A new flavour of Global Warming denial

The IPA is the Australian version of the CEI, so you don't have to read an article they publish on global warming to know what the conclusions will be. But you do have to read it to find out what pretext will be used to dismiss concerns about warming. In the latest issue of IPA review we find an article by two economists (Sinclair Davidson and Alex Robson) that attempts to spread confusion about the IPCC fourth assessment report.

The article is not online, but most of it is available here.

They start off by taking a leaf from Michael Crichton's book -- they change the vertical scale on the graph of global temperatures by a factor of 20 to make the recent temperature increase look smaller. I used the same technique on the temperature data from the Vostok ice core and ice ages turn into tiny little bumps.

i-7e062921bf8580c9a64626126edb2a21-vostok.png

Why do those silly scientists think the climate was different during the last ice age? Using the Crichton/Davidson/Robson method the temperature is not noticeably different.

Damien Eldridge also finds their argument unconvincing.

The second part of Davidson and Robson's article is a bizarre claim that the "IPCC pulls numbers out of thin air":

There are legitimate difficulties with the IPCC's 90 per cent confidence in anthropogenic warming. It is not ludicrous to question what that number means. The IPCC seems to imply that this number results from a scientific process -that it has tested a hypothesis. Indeed, the IPCC tells us its understanding is based "upon large amounts of new and more comprehensive data, more sophisticated analysis of data, improvements in understanding of processes and their simulation in models, and more extensive exploration of uncertainty ranges". If this is what the IPCC has done, it has very weak evidence. Ninety per cent is the weakest acceptable level of confidence in a hypothesis test. It is not clear from the Summary whether the IPCC has, in fact, undertaken such an analysis. It is more likely that it has neither a testable model nor data available for external researchers to replicate such a test. In other words, the IPCC's 90 per cent confidence has emerged from scientists evaluating whether they think their own work is correct.

But look at what the SPM says

This Assessment considers longer and improved records, an expanded
range of observations, and improvements in the simulation of many
aspects of climate and its variability based on studies since the
TAR. It also considers the results of new attribution studies that
have evaluated whether observed changes are quantitatively consistent
with the expected response to external forcings and inconsistent with
alternative physically plausible explanations.

Most of the observed increase in globally averaged temperatures since
the mid-20th century is very likely due to the observed increase in
anthropogenic greenhouse gas concentrations12. This is an advance
since the TAR's conclusion that "most of the observed warming over
the last 50 years is likely to have been due to the increase in
greenhouse gas concentrations". Discernible human influences now
extend to other aspects of climate, including ocean warming,
continental-average temperatures, temperature extremes and wind
patterns (see Figure SPM-4 and Table SPM-1). {9.4, 9.5}

i-e92d89e0d5da6d132868b6c7c5de1802-spm4.png

FIGURE SPM-4. Comparison of observed continental- and global-scale
changes in surface temperature with results simulated by climate
models using natural and anthropogenic forcings. Decadal averages of
observations are shown for the period 1906-2005 (black line) plotted
against the centre of the decade and relative to the corresponding
average for 1901-1950. Lines are dashed where spatial coverage is
less than 50%. Blue shaded bands show the 5-95% range for 19
simulations from 5 climate models using only the natural forcings due
to solar activity and volcanoes. Red shaded bands show the 5-95%
range for 58 simulations from 14 climate models using both natural and
anthropogenic forcings. {FAQ 9.2, Figure 1}

Despite the SPM including a graph that fills an entire page showing the results of tests of models, Davidson and Robson claim that it is likely that the IPCC doesn't have a testable model. Davidson and Robson are taking denial to another level. They have also confused the IPCC's more than 90% probability (what is the probability that most of recent warming is man-made?) with 90% confidence on a hypothesis test (what is the probability that a model with only natural forcings could produce half as much warming as observed?). The hypothesis tests that the IPCC refers to achieved levels of confidence greater than 95%.

It gets worse. Davidson and Robson also claim:

As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

No, elementary textbooks of statistics do not say that. Mainly because it's not true. A larger data set means that smaller effects will be statistically significant, so it is possibly that an effect could be statistically significant but so small that it is not practically significant. Furthermore, if a test does not achieve a specified confidence level, it does not falsify the hypothesis -- all you can say is that there is insufficient data to draw a conclusion.

Sinclair Davidson is a Professor in the School of Economics, Finance and Marketing at RMIT. Alex Robson is a Lecturer in Economics at ANU. It is worrying that economists at Australia's universities have such a poor understanding of basic statistics.

More like this

Rabett Run has a take on yet *ANOTHER* front group. This one is going to play the "well, it's a problem, but we can't do anything about" song and dance.

It's run by Joe D'Aleo, apparently from his house, judged by the registration of the website.

No, no, I'm not having an affair, and besides, she seduced me!

By Meyrick Kirby (not verified) on 12 Apr 2007 #permalink

If they are changing the graph scale to run from 0 to 1000K, does that mean they are expect to have to accomodate a big spike in temperature to something like say 800K! This would easily fit on the graph, although the paper it is printed on might catch fire.

Australian climate-change deniers are getting an assist from the Roman Catholic cardinal who heads the archdiocese of Sydney. Cardinal Pell thinks Gore and others are scaremongers.

Well yes but the Cardinal also thinks secular democracy is a bad idea.

By Ian Gould (not verified) on 12 Apr 2007 #permalink

According to their own publication in 2004, "the IPCC does not conduct new research, monitor climate-related data or recommend policies."

The argument in our IPA Review article is based on what the IPCC says about itself and its own role. They admit that they do not collect data, and that they do not conduct any research or hypothesis tests.

So the basic question we raise still remains unanswered: if they are not monitoring data or conducting new research, where does their 90% figure come from?

By Alex Robson (not verified) on 12 Apr 2007 #permalink

This is so sad and frustrating. Whoever is running the IPA should be fired immediately.

I've tried discussing this with Jennifer Marohasy on her blog, but she isn't interested.

The IPA refuses to move past this lame science denial. They put all their resources into challenging the science. This means that their articles discussing the actual means of mitigating climate change are few and far between - no more advanced than the odd alan moran article saying 'every climate policy will hurt the economy, though nuclear power is best' kind of stuff.

The political climate in Australia wrt climate change has progressed markedly in the last year. And now, Australia is in desparate need of some credible, intelligent and informed conservative thinkers and opinion writers to participate in public debate about policy creation. They need to catch up.

In the last few months, the Australian govt has banned incandescent lightbulbs, and the opposition has committed another idle $50mil to photovoltaic power. There is also the spread of energy efficient housing regulation, which though commendable, is to an extent poorly targeted and less than effective - it could use a strong and intelligent critique, *with suggestions for alternative approaches*.

We need some conservative writers to be critiquing this kind of populist, heavy handed, yet ineffectual fluff policies.

Banning incadescent lightbulbs is a peripheral policy that targets the emissions of individuals at the exclusion of the emissions of the big emitters - power stations. And it curbs individual liberty - a nanny govt policy. (in any case, everyone will switch to halogens, which are worse).

Its politically acceptable to do that, to target green policies at households, but it isn't effective or efficient.

While the IPA is hung up on arguing the science, they have no legitimate voice in participating in discussion of new policy measures to mitigate emissions.

The least bureaucratic, heavy handed means of mitigating climate change that is widely regarded as one of the least cost approaches, is emissions trading. the IPA should be slamming all these inefficient policy measures like banning light bulbs and promote the policy measures that sit best with their free-market pro-individual ethos.

But instead, they keep spinning this anti-science crap, and painting themselves as mining industy shills and extremist anti-science goons. They need to grow up and get new leadership.

Mainly because it's not true. A larger data set means that smaller effects will be statistically significant, so it is possibly that an effect could be statistically significant but so small that it is not practically significant.

That's called a Type III error. Correct answer, wrong question. It's well known that as n tends to infinity the probability of spurious rejection of the null increases. This problem even has a name and a solution. "Lindley's paradox: tiny errors in the null hypothesis are magnified when large data sets are analyzed, leading to false but highly statistically significant results." The point is though, we don't know how data the IPCC have because they don't reveal how they come to their 90% estimate.

By Sinclair Davidson (not verified) on 12 Apr 2007 #permalink

Lambert: "The hypothesis tests that the IPCC refers to achieved levels of confidence greater than 95%". I have searched TL's source, the SFP

Instead, we find that "there is high confidence (i.e. 80%) that the rate of sea level rise increased from the 19th C to the 20th C". First, as there is no evidence on what the RATE of sea level rise was before 1900, how can the IPPC so "highly" confident that the RATE has increased since 1900? Second, "the total 20th C rise is [highly confidently] estimated to be 0.17 (0.12 to 0.22) m". When the range is 30% either way, the claimed level of confidence is close to meaningless. If your surgeon was highly confident that a course of aspirins would raise your life expectancy by 2 weeks, +- 30%, it could be time to change to another. However I will cite the IPCC to my Mebourne Cup bookie to get him to adjust my odds by 30% either way.

IPCC: Red shaded bands show the 5-95% [i.e. up to] range for 58 simulations from 14 climate models using both natural and anthropogenic forcings. {FAQ 9.2, Figure 1)

Time Lambert The hypothesis tests that the IPCC refers to achieved levels of confidence greater than 95%.

Sinclair, you claimed that this was in any elementary stats book. It isn't. Why don't you provide a cite to an elementary stats book that tells you that you have to increase the significance level with large samples? I agree with [Chris from Mixing Memory](http://scienceblogs.com/mixingmemory/2006/10/jeffreylindley_paradox.php) on Lindley's paradox -- it's not a problem in practice.

In any event it's only a problem with frequentist statistics, and the AR4 report cited plenty of Bayesian attribution studies as well. [For instance](http://luv.dkrz.de/publications_2005/pub_193_372.pdf):

>A Bayesian approach is applied to the observed global surface air temperature (SAT) changes using
multimodel ensembles (MMEs) of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment
Report (AR4) simulations and single-model ensembles (SMEs) with the ECHO-G coupled climate
model. A Bayesian decision method is used as a tool for classifying observations into given scenarios
(or hypotheses). The prior probability of the scenarios, which represents a degree of subjective belief in the
scenarios, is changed into the posterior probability through the likelihood where observations enter, and the
posterior is used as a decision function. In the identical prior case the Bayes factor (or likelihood ratio)
becomes a decision function and provides observational evidence for each scenario against a predefined
reference scenario. Four scenarios are used to explain observed SAT changes: "CTL" (control or no
change), "Nat" (natural forcing induced change), "GHG" (greenhouse gas-induced change), and "All"
(natural plus anthropogenic forcing-induced change). Observed and simulated global mean SATs are
decomposed into temporal components of overall mean, linear trend, and decadal variabilities through
Legendre series expansions, coefficients of which are used as detection variables. Parameters (means and
covariance matrices) needed to define the four scenarios are estimated from SMEs or MMEs. Taking the
CTL scenario as reference one, application results for global mean SAT changes for the whole twentieth
century (1900-99) show "decisive" evidence (logarithm of Bayes factor >5) for the All scenario only. While
"strong" evidence (log of Bayes factor >2.5) for both the Nat and All scenarios are found in SAT changes
for the first half (1900-49), there is decisive evidence for the All scenario for SAT changes in the second half
(1950-99), supporting previous results. It is demonstrated that the Bayesian decision results for global mean
SATs are largely insensitive to both intermodel uncertainties and prior probabilities.

Steve -

This is what I see as one of the worst effects of AGW denialism - it has effectively meant that all suggested policy solutions have come from what I'd call the environmentalist-left.

Unfortunately, this grouping also tend to be highly suspicious of large industrial enterprises (which is fair enough in some ways..) and therefore favours small scale and/or 'natural' solutions. Hence Wind, Biofuels, Efficiency, and at the most extreme Relocalisation. All of which sound great on paper, lead to very nice pilot projects but stand no chance whatsoever of scaling up to the degree required to actually make a difference.

(And if you don't believe me on the above, feel free to show me an instance where any of the above have put a noticeable dent in the CO2 emissions of a country.)

So denialism of global warming has had the (unintended?) side effect of ensuring that reduction/mitigation policies are largely ineffective.

By Andrew Dodds (not verified) on 13 Apr 2007 #permalink

Tim, every stats book should show the confidence bound calculation as being a function of the standard error which is the standard deviation divided by the square root of the number of observations. As the number of obs gets big so the square root get big etc. I am shocked to hear this isn't a problem in practice. In finance data we often have large data sets and this is a problem. The IPCC claim to have a large data set, and if they do then Lindley's paradox might be a problem. Now do they have a lerge data set or don't they? If they do then Lindleys paradox is a problem, if they don't and Lindley isn't a problem then they don't have a large sample. Who do I believe? The IPCC or you? How is the 90% value derived? If they were transparent as they are required to be, then we wouldn't be having this debate.

By Sinclair Davidson (not verified) on 13 Apr 2007 #permalink

"We need some conservative writers to be critiquing this kind of populist, heavy handed, yet ineffectual fluff policies."

Good luck with that. It's probably close to a decade ago that I tried to convince my then-employer the Queensland EPA to shift the subside on hot water systems from the end-buyer to the distributor or manufacturer. This would have been more cost-effective and also probably have resulted in a higher uptake. (I'm not going to argeu the benefits of subsides here, just making the point that a $500 drop in the wholesale price will probably lea to a more than $500 drop in the retail price and therefore to more consumption of the subsidised good.)

We quickly got the word from the political level to drop the idea - what mattered was solely those government cheques showing up in voter's mailboxes.

"Banning incadescent lightbulbs is a peripheral policy that targets the emissions of individuals at the exclusion of the emissions of the big emitters - power stations. And it curbs individual liberty - a nanny govt policy. (in any case, everyone will switch to halogens, which are worse)."

Umm Steve if individuals electricity consumption goes done, what do you think will happen to emissions from power stations?

As for people shifting to halogens, all I can say is that from personal observation compact fluros have virtually disappeared from shop shelves around Brisbane since the ban plan was announced. Somebody's buying them.

"Banning incadescent lightbulbs is a peripheral policy that targets the emissions of individuals at the exclusion of the emissions of the big emitters - power stations. And it curbs individual liberty - a nanny govt policy. (in any case, everyone will switch to halogens, which are worse)."

How I wish that were so, I supply a vital component for halogens and not for incandescents or CFLs. However, from within the light bulb industry that's not what seems to be happening. Before the Australian and EU bans were announced (although after Venezuela and Cuba's) metal halide bulb production was roughly static at some 100 million a year while CFL production this year has ramped up to 1 billion (that's a minimum).

The bans will have very little efect: for the markets were already making the switchover. But at least it will give the politicians something to crow about, even if they didn't actually cause the change.

Dear Sinclair:
What the hell?
Large samples give more power, better stability for non-zero effects, and better stability to estimate effect sizes. Consider the IPCC process as a meta-analysis, across measures, methods and sites. Notice how the estimated effects for warming have not changed at the means since the last report, but the confidence intervals have decreased.
in any case, it's the effect size that's important. We're not talking about a statistically significant, meaningless change of .03 degrees - we're looking at several degrees, which those climatology folk seem to get exercised about. I'm not a climatologist, but I'd take scientists in their own profession at their word, without strong evidence to the contrary.
You wouldn't tolerate that sort of statistical bait and switch nonsense from a left-leaning undergrad, being Conservative doesn't give you a free pass on it either.

Stewart - I don't disagree with your sentiment. I had expected them to have done a meta-analysis. (Although it turns out the IPCC claim not to do any sort of analysis.) But it's not clear that that has happened. It's not clear what has happened. Now if any student had written that piece I would say "where does the number come from? make it obvious". It is not obvious. Tim keeps on saying I don't understand stasitics. Okay fine. Whatever. But if I don't understand what the IPCC are doing in their Summary for Policymakers, why do we expect policymakers to understand what they have done? The IPCC have a mandate to be open and transparent. It is not too much to hold them to that mandate.

By Sinclair Davidson (not verified) on 13 Apr 2007 #permalink

Zeno,

I read Cardinal Pell's article. Here's the best bit:

"We know that enormous climate changes have occurred in world history, e.g. the Ice Ages and Noah's flood,"

By Tony Jackson (not verified) on 13 Apr 2007 #permalink

Sinclair, your claim was not that stats books say that large samples give you smaller confidence intervals, but this:

>As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

Please provide a cite to an elementary textbook of statistics that states this. Surely this cannot be too hard for you?

Sinclair, in their SUMMARY for Policy Makers they are SUMMARIZING their assessment of the research. It is a SUMMARY. Hence the title. The numbers in the SUMMARY refer you to sections in the full report which go into all the details of the research that they ASSESSED in the 4th ASSESSMENT Report. I know this will bounce off your fact shield.

alright, so it seems that:

a. global warming is a scientific theory largely supported by the research conducted with the resources and information available to the scientific community at this time

b. many measures taken/proposed to curb global warming have met extensive-and often justified- criticism because they are ineffective

so, assuming global warming to be a valid theory (frankly, if I received a telephone call saying that fourteen thousand people were about to be shot and that I could save them but only if I gave up my boat I'd rather risk losing the boat for nothing than letting 14 thousand people die for no reason- maybe that's just me, in which case debating the legitimacy of global warming is perfectly constructive)what SHOULD be done? I understand the criticisms of many of the suggested measures, but this is a problem that can be largely controlled, so does anyone have any constructive suggestions?

alright, so it seems that:

a. global warming is a scientific theory largely supported by the research conducted with the resources and information available to the scientific community at this time

b. many measures taken/proposed to curb global warming have met extensive-and often justified- criticism because they are ineffective

so, assuming global warming to be a valid theory (frankly, if I received a telephone call saying that fourteen thousand people were about to be shot and that I could save them but only if I gave up my boat I'd rather risk losing the boat for nothing than letting 14 thousand people die for no reason- maybe that's just me, in which case debating the legitimacy of global warming is perfectly constructive)what SHOULD be done? I understand the criticisms of many of the suggested measures, but this is a problem that can be largely controlled, so does anyone have any constructive suggestions?

"IPCC: Red shaded bands show the 5-95% [i.e. up to] range for 58 simulations from 14 climate models using both natural and anthropogenic forcings. {FAQ 9.2, Figure 1)

Time Lambert The hypothesis tests that the IPCC refers to achieved levels of confidence greater than 95%."

Ouch, that's a hardcore misunderstanding of statistics.

The 5-95% refers to the range in which anthropogenically caused warming is 90% likely to occur. I.e. there's a 90% chance that anthropogenic forcing is responsible for X amount of warming. This is the bright red band in the figure.

A 95% confidence interval is for all intents and purposes the probability the observed data is due to anthropogenic forcing. I.e. there's a 95% chance that the black line is inside the red band because anthropogenic forcing leads to warming (and therefore a 5% chance that that black line is in there due to random chance).*

*More accurately, a confidence interval refers to the probability of the null hypothesis given the data.

By LogicallySpeaking (not verified) on 13 Apr 2007 #permalink

""We know that enormous climate changes have occurred in world history, e.g. the Ice Ages and Noah's flood,""

I knew the Cardinal was in an advanced state of decrepitude but I didn't realise he regarded the ice ages as within the scope of recorded history.

By Ian Gould (not verified) on 13 Apr 2007 #permalink

You'll appreciate I haven't checked each of these books myself, but I suspect all of them will have section on hypothesis testing. Most chapters include a discussion of confidence levels, Type I and Type II errors and the like.

But Tim, you digress. Where does the 90% figure come from?

By Sinclair Davidson (not verified) on 13 Apr 2007 #permalink

I obviously haven't read AR4, and it appears neither have you (you only seem to be aware of the summary for policymakers). That said, I'm not even sure if the full document has been released yet.

Nonetheless, I'd assume that the 90% is derived from peer-reviewed publications. Something along the lines of 90% of climate models require anthropogenic forcing to within a certain confidence interval. Given the amount of skepticism present on the IPCC panel, I'd assume it's a rather high confidence interval, and not just 95%.

By LogicallySpeaking (not verified) on 13 Apr 2007 #permalink

Cardinal Pell isn't worried about global warming because he knows that Heaven is a very hot place, in fact, Heaven is hotter than Hell, as can be deduced from Isaiah 30:26 and Revelations 21:8.

We're talking about the SPM - that has been clear from the beginning. The AR4 report is being released in stages. I am only able to read documents in the public domain.

Nonetheless, I'd assume that the 90% is derived from peer-reviewed publications.

The operative word here is "assume". The IPCC are required to be open and transparent. We should not have to assume anything. They have reported a number (indeed several numbers) and all I'm asking for is an explanation of where that number came from. (Of course, four of the numbers have no human attribution study at all - so where did those numbers come from, given the IPCC admit they don't come from peer-reviewed publications, or indeed any publication).

By Sinclair Davidson (not verified) on 13 Apr 2007 #permalink

Sinclair: I'm 90% certain it was a show of hands

"We're talking about the SPM - that has been clear from the beginning. The AR4 report is being released in stages. I am only able to read documents in the public domain."

Fair enough, but you can't criticize them for not including all of the details in a summary. It would be equivalent to being a handed the abstract of a paper, told that the full paper will be viewable in a few months, and then proceeding to critique the abstract for not being open and transparent.

"The IPCC are required to be open and transparent. We should not have to assume anything. They have reported a number (indeed several numbers) and all I'm asking for is an explanation of where that number came from."

I agree with you here. Could you give us a general idea of whom you attempted to contact that is affiliated with the IPCC that was unwilling to answer your question(s)? Or what their response was when you posed this question of them?

By LogicallySpeaking (not verified) on 13 Apr 2007 #permalink

I am unable to contact the IPCC directly because I don't have ethics approval to collect data from human subjects. I was hoping there documentation would be open and transparent enough to provide an answer to the question. Afterall, that 90% figure is the crux of the whole issue.

By Sinclair Davidson (not verified) on 13 Apr 2007 #permalink

"I read Cardinal Pell's article. Here's the best bit:

"We know that enormous climate changes have occurred in world history, e.g. the Ice Ages and Noah's flood,""

But the ice ages didn't really happen because the world was created in c. 4000 BC (along with all the evidence to trick humans into believing that the earth is much older). Hasn't Pell been keeping up with his Bible studies?

By Chris O'Neill (not verified) on 13 Apr 2007 #permalink

Logically speaking: You are right, I was merely trying to find TL's source in the SPM. His pretty figs at the beginning of this thread are all very fine, but the red and blue bands are clearly stated to be the outcomes of modelling using various assumptions about solar effects, volcanoes, and CO2. Where are the data inputs for these assumptions and statistical analysis thereof (preferably in Excel format complete with cointegration, ts, ps, etc)? Counting up and then averaging computer model simulations is NOT a valid test of an hypothesis.

Sinclair, you didn't say that elementary stats book discuss hypothesis testing but that:

>As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

If your statement is true, it would be easy for you to provide just one example. Why can't you do this? Is it because you claim is a fabrication?

Where did the IPCC get their numbers from?

By Sinclair Davidson (not verified) on 13 Apr 2007 #permalink

It's explained in the full report, Sinclair.

If your statement about stats texts is true, it would be easy for you to provide just one example. Why can't you do this? Is it because your claim is a fabrication?

Fabrication in what sense?

By Sinclair Davidson (not verified) on 14 Apr 2007 #permalink

TL & SD: One recent standard text (Charles Feinstein and Mark Thomas, the late Charles was quondam editor of the EJ) states that "any confidence interval is directly affected by the size of the sample on which it is based" (p.140)

..but the red and blue bands are clearly stated to be the outcomes of modelling using various assumptions about solar effects, volcanoes, and CO2.

Um, where do get the idea that they are assumptions?

Tim C,

No, you said they made assumptions about volcanoes, solar and CO2. Furhter, you said this was clearly stated. Where is it clearly stated?

Abe: The pics at the beginning of this thread state that the bands show the results of about 76 different simulations. If the data did not change, why so many simulations? So am I right that what we have is about 76 alternative theories, none of which has been tested against the data? One million computer models with the same data but differing theories do not aggregate into a test of the nul hypothesis that anthropogenic effects are innocent of causing climate change. What is your hypothesis? what are your data for testing my nul hypothesis?

By Tim Curtin (not verified) on 14 Apr 2007 #permalink

Sinclair: fabrication in the sense that elementary texts do not say that "with large data sets, confidence intervals have to be increased" but rather you and Alex Robson made that part up. It is trivial to prove that you didn't -- just cite one elementary text that says it. How about it?

Where did the IPCC get their numbers from?

What part of "wait for the paper" do you not understand???

By David MarjanoviÄ (not verified) on 14 Apr 2007 #permalink

So what's the effect size? Are you saying GW is real but trivial and makes no difference, or are you saying you don't care, you just found a handy stick that doesn't actually fit the question?

I see that the various National Academies and other learned bodies all take this very seriously. Don't all of these folks have to do something with statistics at times? Maybe the EC and all these first world academics just have deep-seated Stalinist tendencies?

Sinclair, this is just another variation on 'climate scientists are fools', dressed up with a little more statistical jargon. Now. I understand that economists and string theorists are fighting it out to see who is the smartest, and all other disciplines are populated by fools, but they put in the time and effort to learn their discipline. It's rude to say they are fools without clarifying how.

That's a very agressive stance you're taking Tim. You're leaving no wiggle room for yourself. I'm wondering what you're going to do when I name a book?

I'll give you a clue. While some hardcover versions did come out, it's a big fat blue paperback with a spine that cracks easily.

By Sinclair Davidson (not verified) on 14 Apr 2007 #permalink

Stewart, this is about accountability. This is about irritation about climate change hype. The SPM is actually more nuanced than people think and despite drawing on a lot of work the limits of what is known are quickly reached. A number of 90% gets thrown out with no context of meaning. Human attribution numbers get thrown out with the admition there is no human attribution study. They have no brief to manufacture those numbers and they have no brief to hype up their results. As Alex and I say nobody is calling for the environment to be despoiled, and as I have written elsewhere there may be good arguments for a carbon tax indepedent of any climate change. The problem Tim is having is that he has set Alex and I up sterotypical denialists (in his own image of such people). So Tim and I have had this debate here and at Catallaxy for the past week (and an earlier exchange last month) and you'll notice he keeps changing the subject - so right now he wants me to name a textbook in my office bookcase. Rather than concentrate on the issue - how did the IPCC derive their headline number? As David suggests it might be in the main reports (or one of them, at least). This may all be a poor presentation problem and then Alex and my argument will all be a non-issue.

By Sinclair Davidson (not verified) on 14 Apr 2007 #permalink

"Umm Steve if individuals electricity consumption goes done, what do you think will happen to emissions from power stations?"

No need to be condescending, I'm not an idiot.

WHen you consider that electricity is about 34% of australia's emissions, residential electricity is maybe 30% of that, and lighting is <10% of residential electricity, and many people are already switching to CFLs or to halogens, and CFLs are not zero power consumption, then multiplying all those fractions out gives a policy that has small potential for GHG reductions, big impact on the general public, and big media posturing. I'd hate to be the low level policy officer fielding phone calls from fridge light bulb manufacturers, people who get headaches from fluro lights, microwave lightbulb manufacturers, torch lightbulb manufacturers, xmas tree light manufacturers, lava light manufacturers etc who don't know WTF to do and how this new lightbulb policy will affect them.

Where was the conservative criticism? Where were the conservatives saying 'let the market decided how to reduce emissions and stop this proliferation of ad-hoc policies aimed at the punters'? They were busy with the climate change denial.

A sensible and conservative IPA policy is not climate denial. It is acceptance of the consensus, and campaigning for long term targets, steady progress, simple and broad policy responses, and anti lotsa bitsy pricey policies supporting light bulb bans and solar power etc. The IPA should be pro- broadly applied emissions trading and anti every other climate mitigation policy.

I'm not conservative, but i do flinch when i hear some of the inane or even ineffectual policy suggestions coming from some corners of the green-left side of politics. We need a constructive *and credible* yet conservative voice to balance this. The IPA is currently not credible with their denial message.

TimW, when I talk about halogens, i mean the halogen downlights that are currently the norm in most well to do urban homes (3,4, 5+ bulbs per room), not metal halide floodlight kind of gear.

Sinclair, the normal practice when citing a book is to give the author and title. I'm afraid that "big fat blue paperback" isn't a very useful way of citing.

I did not cast you as a stereotypical denialist. Didn't you notice the title of this post? "A new flavour of Global Warming denial". You are doing soemthing different -- denying the existance of the attribution studies the IPCC cites. Even though I posted the abstract and a link to one of them in this thread.

How does
"any confidence interval is directly affected by the size of the sample on which it is based"
imply
"with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid"
?
Particularly when the first statement is true, but that second statement is impossible to interpret in any way that corresponds to actual statistical theory or practice, (or even makes sense on a standalone basis)?

"As the number of obs gets big so the square root get big etc. I am shocked to hear this isn't a problem in practice. In finance data we often have large data sets and this is a problem. "

Let me get this straight. Are you saying that in the graphic above, the fact that the data follows the pink prediction and not the blue prediction is invalid, because there is (or might be?) **too much data**??? And that this argument is commonly held to be valid in the world of finance? If so, that would explain one hell of a lot regarding the strange refusal of trickle down economics to stay decently dead, for instance.

Tim, I'm sorry if if misrepresented your argument. I was taken in by the sentence where you said you don't need to read stuff to know the outcome. Yes, I have accussed the IPCC of not having human attribution studies because they say they don't have the studies. Accuse is too strong a word perhaps, quote would be a better phrase.

Yes, it can happen that having too much data biases standard hypothesis tests. It wouldn't happen unless you have many thousands of data points. I don't know how much data the IPCC have - they say they have a large data set and then report a marginal confidence level of 90%. In that situation my first thought is always "Lindleys paradox? Is it a problem here?" It may not be, but I reckon they never even thought about it. (To be fair, most people don't worry about it because having large datasets is a recently luxury). Now, it may be they don't have dataset large enough for Lindleys paradox to even be a problem, but again we don't know. It's just not good enough. If the IPCC are preaching to the choir then the SPM is fine. But if they are trying to provide a summary of evidence for use by policy makers, they the SPM is poor job. Why is that?

Tim, the book is Judge etal. Intro to practice of econometrics (title from memory) it's out of print now. Another is by Zellner that's an intro to Baysian stats (probably of out of print too). Leamer wrote about this as well in one of his books (probably not an intro, from memory). There are also a few articles aimed at students and practitioners that bring this up. In stock market data this can be a serious problem especially when using high frequency data (or even long periods of faily data). Climate data is not high frequency but there might be several thousand observations in any one dataset if not more(afterall there are millions of years of climate change). It is something that needs to be checked. If not a problem it needs to be footnoted, if a problem it needs to be adjusted for. 90% confidence may not be statistically significant in large sets. Of course we can quibble about the definition of large and the SPM is silent on that.

Thank you, all. This has been a very civilised (and fun) discussion.

By Sinclair Davidson (not verified) on 15 Apr 2007 #permalink

Steve

You are too pessimistic on non-carbon energy sources.

Wind capacity, worldwide, is growing at 30% pa. That kind of exponential growth (doubling capacity every 2.5-3 years) means wind power is going to be a significant source of energy. 60GW installed capacity now, but quite credibly 1000GW installed capacity by 2025. (US is about 800GW installed capacity for all forms of electricity generation).

And it's a big business. In Spain, Germany, Denmark, the UK and the US (notably that home of green sentiment, Texas), it's some of the largest power companies in the world that are investing.

Average cost per GW of wind capacity is falling by c. 18% with each doubling of sector size (the normal learning curve effect).

And offshore wind, which is even more promising (because the wind even 3 km offshore blows much more frequently, and stronger), is barely beginning.

In some markets (Ireland) new wind capacity (without subsidy) is competitive with new gas fired plant.

Because we don't tax carbon emissions, wind still requires subsidies to be competitive (but, like nuclear, the capital cost is all up front, the operations & maintenance is a relatively small figure, whereas with a gas-fired combined cycle (CCGT) plant, fuel is 2/3rds of the lifetime cost of plant).

I am all for sensible macro policies (like carbon taxation).

Where there is a role for 'regulatory' solutions is in areas where:

- consumers aren't necessarily motivated by energy costs. Economists have shown consumers will not make energy saving expenditures (eg buying a better fridge) that have a 3 year payback (40% Internal Rate of Return). Compact Fluorescents have a positive NPV, yet consumers don't buy them.

That's a 40%, guaranteed, annual return that consumers are turning down.

Interestingly, when it comes to energy conservation incentives, industry functions on similar payback rules (2-3 years to justify) which is a far higher (and safer) return that venture capital demands.

See all the papers on 'hyperbolic discounting' by Laibson et al, as well as the work of Kahneman, Tversky and Thaler and Meir Statman ('Prospect Theory' and 'Behavioural Finance') to see why this might be so.

- situations of limited information when consumers don't know what the lifecycle energy costs of what they are buying is

- split incentive problems eg in commercial lets, the tenant pays the energy cost, but the landlord specifies the building (typically at lowest cost). The tenant won't be around long enough to reap the benefits of more efficient heating, ventilation, air con etc, and the landlord doesn't care

- 'white roofs' - this one has been studied to death at Berkeley's Energy lab. Painting the roofs of the houses and buildings of the southern 2/3rds (roughly) of the USA white can save up to 10% of all air conditioning bills (the offset in terms of lost winter insolation is about 1%). Much of the benefit of this action actually accrues to your *neighbours* (who don't get the heat spilled out from your air con) and people *driving by* ditto. So it won't happen if we don't collectively mandate it (benefit to me isn't worth the hassle).

Whilst electricity consumption per head in the US since 1980 has risen by 40%, in California it has risen not at all, despite California being the 5th (?) richest state in the Union. This is the consequence of tough energy efficiency standards and a model of what the rest of us can achieve.

By Valuethinker (not verified) on 15 Apr 2007 #permalink

Valuethinker, somehow "Theory and Practice of Econometrics (Probability & Mathematical Statistics S.)" doesn't sound like an elementary text to me.

Apparently the publishers don't think so either: "This broadly based graduate-level textbook covers the major models and statistical tools currently used in the practice of econometrics."

I'm sure Sinclair had something else in mind.

By Ian Gould (not verified) on 16 Apr 2007 #permalink

1. A low number of samples guarantees high variability
2. For a large number of samples to cause trouble the noise probably has to be non-Gaussian in ways that are not understood (for example assuming white noise when it is red).

Sinclair, the IPCC SPM says they have attribution studies. I already quoted the abstract and linked to one. Care to comment on it? Oh right, you're not going to because then you would have to admit that exists. Why don't you just simplify things and deny the existance of the IPCC while you are at it?

I guess that is also why you haven't looked at the graphs in my post that show attribution studies using the last 100 years of data. That's not a lot of data, and the only reason why can detect significant effects is because the effects of anthro ghgs stick out like a sore thumb.

And no, the SPM did not do a bad job. The fact that you went over it looking for excuses to dismiss and couldn't come up with anything of substance demonstrates that they did a good job.

Tim, the IPCC have a footnote to the table saying there is no attribution study. You will recall I said this had occurred in three cases, and you corrected me by saying it was in four cases. So last week at Catally you agreed there were no attribution studies, now you deny it? Why would I deny the existence of the IPCC? Again you're debating a caricuture and not me.

What I want to know is where did the 90% figure come from? What does it mean? Afterall that figure is the nub of the whole issue? Tim, if you don't know, just say so.

Value - I have in mind the baby version of the book you linked to.

By Sinclair Davidson (not verified) on 16 Apr 2007 #permalink

Value: Falling costs of windmill capacity are important but costs per GH HOUR actually delivered are also highly relevant; unfortunately low capacity utilisation rates tend to offset falling capex costs and low (but not zero) running costs. To compare only installed capacity is seriously misleading: what is windmills' share of annual output of GWh in say Spain as % of its share of installed capacity?

Sinclair Davidson and Alex Robson of the Australian Financial Review agree with me that there is no statistical significance to prove that humans are the cause of increased temperatures.

Tim Lambert, in his rebuttal of their article also concludes that "all you can say is that there is insufficient data to draw a conclusion."

So thanks Lambert in saying that we don't have enough data to draw a conclusion. Unfortunately as proven by me previously, we do, and the result is still insignificant.

http://gustofhotair.blogspot.com/

Johnathon Lowe thus, by virtue of a blog comment, overturns the findings of a generation of scientists. Scientists publishing hundreds if not thousands of papers relating their empirical findings.

Galileo Johnathon will certainly become a millionaire and enjoy well-catered events on the Heritage Victory Tour and the Mighty Wurlitzer Dream Team parades.

Sadly, Johnathon will become fat at these events, leading to thousands of enviros derisively calling him fat and energy-wasting, negating all his arguments and putting us back to square one before Johnathon's Galileo-like strike at the heart of the environazi movement. Or something.

Best,

D

No Dano,
my comment is purely to suggest that the 90% as given by the IPCC is a purely political statistic that is simply just made up. It has no statistical base whatsoever, and if it did (which is doesn't) fails at the 5% level of significance.

Havent been back in a while, but it appears Lambert is just the same blowhard. What was with the argument that it WASN'T an elementary text? Why even bother dealing with that? How pathetic.

I am sick of the peicemeal approach the IPCC has in releasing information. Hold on to it untill you can release it all, instead of releasing soundbites here and there to whip up hysteria and to get pavlovs climate-dogs salivating.

Value, i think you'll find we are on the same page. my point isn't so much to disparage energy efficiency or renewables, its to demostrate the role that conservative groups like the IPA should be taking instead of putting themselves in the 'to be ignored' bin with their attempts at climate science analysis.

Although, I think that it is premature to be spending money directly on wind power, or confusing everyone with a vast array of piecemeal initiatives (such as lightbulbs) when we dont have a carbon price. first things first - put a price on carbon and let the best technologies win. AFter that, it will be easier to target supporting policies where they are required.

---

PS what do you think the reason is that people dont put in CFLs without prodding, even though it will save them money?
Its not because they need government to regulate them to do it. Its because they quite understandably see quality of light as a much much much more important issue than the small expenditure difference on the electricity. I'm keen to be green and I have CFLs throughout the house, but I can honestly say that even the new, warmer light CFLs dont provide as good ambience as a bank of halogen downlights. You might disagree. So you can put in CFLs and i wont (i will, but for arguments sake, assume i dont), but i will pay for the privilege and reduce emissions via the market.

Steve, what you suggest re. setting a carbon price and letting the market sort things out is exactly what I have been advocating here and elsewhere for years.

One small comment though: this isn't really a "conservative" strategy - its a sensible market-based strategy which should be supported by economically literate people across the political spectrum.

The lack of support from both ends of that spectrum simply shows how rare economic literacy is.

By Ian Gould (not verified) on 16 Apr 2007 #permalink

Sinclair Davidson and Alex Robson of the Australian Financial Review agree with me that there is no statistical significance to prove that humans are the cause of increased temperatures.

Looking forward to reading about this in a peer reviewed scientific journal.

When do you expect it to come out?

By Ken Miles (not verified) on 16 Apr 2007 #permalink

Thanks for finally providing a proper cite, Sinclair. The UNSW library has a copy of "Introduction to the Theory and Practice of Econometrics" (2nd Edition) by Judge et al. In section 3.5 Hypothesis Testing I find (page 98):

>As a final note on the power of a test, note that for a given level of significance of the test, α, as the sample size increases (to infinity) the power of the test increases (to one) for every β ≠ 1. The intuition for this is based in the fact that the test is constructed around a consistent estimator. As the sample size increases, the sampling distribution of the estimator collapses about the true parameter value, and thus the probability that we would reject a false hypothesis goes to unity. Tests with this property are called *consistent tests*.

Judge provides no support (in over a thousand pages) for Sinclair's claim:

>As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

I also went to the UNSW book store and looked at all the elementary textbooks on statistics and econometrics. None of them said what Sinclair claimed they did. None of them.

Sinclair, I think you need to send a correction for your article to IPA Review.

Johnathon, I hate to break it to you and the ideological minority to which you adhere, but the society train has left the station wrt man-made climate change. Let's act out we're saying buh-bye to you and your ilk, shall we:

[Opens paper]

Huh.

[Reads]

"ConocoPhillips has joined several other major corporations urging Congress to require limits on greenhouse gases tied to global warming, the first major U.S. oil company to take such a stance."

Gee.

[Turns page, reads]

"The Supreme Court ordered the federal government on Monday to take a fresh look at regulating carbon dioxide emissions from cars...

"In many ways, the debate has moved beyond this," said Chris Miller, director of the global warming campaign for Greenpeace, one of the environmental groups that sued the EPA. "All the front-runners in the 2008 presidential campaign, both Democrats and Republicans, even the business community, are much further along on this than the Bush administration is."

...The world's leading climate scientists reported in February that global warming is "very likely" caused by man and is so severe that it will "continue for centuries."

Golly.

[Turns page, reads]

"On Friday, Massachusetts joined Oregon, Connecticut and five other states in adopting California's tough greenhouse gas rules, which limit the amount of carbon dioxide and other gases that can be emitted from vehicle tailpipes. These new rules would supplement federal exhaust pollutant standards already in place. Two other states are in the process of adopting the rules."

Whaddya know.

[Turns page, reads]

"Duke Energy Corp.'s Chief Executive Jim Rogers said this morning's release of an international report that blames humans for global warming should spur approval of a national cap on carbon dioxide he and other business leaders proposed last month."

Wowie.

[Turns two pages, reads]

"As lawmakers on Capitol Hill push for a cap-and-trade system to rein in the nation's greenhouse gas emissions, an unlikely alternative has emerged from an ideologically diverse group of economists and industry leaders: a carbon tax...

[A] coalition of academics and polluters now argues that a simple tax on each ton of emissions would offer a more efficient and less bureaucratic way of curbing carbon dioxide buildup, which scientists have linked to climate change."

Even th' polluters. Sheesh.

[Puts paper down. Pause. Looks out the rear window of the society train, to the receding station platform. Turns to companion]

"Say, who's that jumping up and down, waving their arms?"

"Dunno. Looks like one of them denialists or maybe a contrascientist or somebody like that."

"What's he yelling?"

"Can't tell. We left too long ago to hear."

"Shall we stop the train?"

"What for? What have they ever said that was worth listening to?"

"Eh. You're right."

[Opens paper]

Huh.

[Reads]

"Germany, the second largest market for photovoltaics, positioned itself with the 100,000 Roofs Program, launched in late 1998, which provided 10-year low-interest loans for PV installation (it ended early, in 2003, when all targets were met). Germany now leads the way with an Electricity Feed-in Law that started in 1999, which permits most customer applications to receive 45.7 euro cents per kilowatt-hour (kWh) (56¢ per kWh) for solar-generated electricity sold back to the grid."

Best,

D

Tim, eye on the ball. I also provided Zellner and Leamer as refs. I have others too, there is a nice example in Walpole, Introduction to Statistics (but he doesn't expand on it), and Rao. But unless you want to argue I fabricated Lindleys paradox (I'm sure I would have called it 'Davidson's paradox'), and the formulas that underlie hypothesis testing (especially the bit about dividing through by the square root of n) I'm not sure where this leaves your argument about the IPCC. This isn't about me. This is about the IPCC and their claims about AGW. They have a figure of 90%, where did that number come from? Where did the numbers that the IPCC admit have no human attribution study underlying them come from? This is not hard. If you don't know, just say so.

By Sinclair Davidson (not verified) on 17 Apr 2007 #permalink

Apparently Sinclair's references weren't sufficiently introductory. So let's look at some more. How about Peter Kennedy's (1998) "A Guide to Econometrics", Fourth Edition, Cambridge, MA: MIT Press?

On page 64, Kennedy writes:

"One of the more interesting problems is the fact that almost any parameter can be found to be significantly different from zero if the sample size is sufficiently large. Thus, although a researcher wants a large sample size to generate more accurate estimates, too large a sample size might cause difficulties in interpreting the usual tests of significance. This is called the too-large sample size problem. It is suggested that the significance level be adjusted downwards as the sample size grows. For a formalization, see Leamer (1978, pp88-9, 104-5)."

According to the back cover, Kennedy's book is "the first-choice text for teachers and students throughout the world who require an intuitive introduction to the subject without the notation and technical detail that characterize most textbooks."

I have quite a large private library in my ANU office. Sinclair owns hundreds of books. How many references would you like us to cite?

By Alex Robson (not verified) on 17 Apr 2007 #permalink

Alex, how about one - just one - that includes that bit about the hypothesis being falsified?

By Kevin Donoghue (not verified) on 17 Apr 2007 #permalink

Sinclair, you didn't fabricate Lindley's paradox -- you just don't understand that it is of little practical significance, which is why elementary stats textbooks don't mention it, including the one you claimed did. Here's what you wrote again:

>I'll give you a clue. While some hardcover versions did come out, it's a big fat blue paperback with a spine that cracks easily.

and

>Tim, the book is Judge etal. Intro to practice of econometrics (title from memory) it's out of print now.

Why did you name a book that did not support your claim? Can you explain why the 1000+ page book that you did name did not support your claim:

>As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

Do you think Judge et al is a bad text book or what?

Why do you keep asking where the 90% probability comes from when you 've been told the answer over a dozen times?

Why do keep trying to pretend that they don't have attribution studies when I've posted [this one](http://luv.dkrz.de/publications_2005/pub_193_372.pdf)?

>A Bayesian approach is applied to the observed global surface air temperature (SAT) changes using multimodel ensembles (MMEs) of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) simulations and single-model ensembles (SMEs) with the ECHO-G coupled climate model. A Bayesian decision method is used as a tool for classifying observations into given scenarios (or hypotheses). The prior probability of the scenarios, which represents a degree of subjective belief in the scenarios, is changed into the posterior probability through the likelihood where observations enter, and the posterior is used as a decision function. In the identical prior case the Bayes factor (or likelihood ratio) becomes a decision function and provides observational evidence for each scenario against a predefined reference scenario. Four scenarios are used to explain observed SAT changes: "CTL" (control or no change), "Nat" (natural forcing induced change), "GHG" (greenhouse gas-induced change), and "All" (natural plus anthropogenic forcing-induced change). Observed and simulated global mean SATs are decomposed into temporal components of overall mean, linear trend, and decadal variabilities through Legendre series expansions, coefficients of which are used as detection variables. Parameters (means and covariance matrices) needed to define the four scenarios are estimated from SMEs or MMEs. Taking the CTL scenario as reference one, application results for global mean SAT changes for the whole twentieth century (1900-99) show "decisive" evidence (logarithm of Bayes factor >5) for the All scenario only. While "strong" evidence (log of Bayes factor >2.5) for both the Nat and All scenarios are found in SAT changes for the first half (1900-49), there is decisive evidence for the All scenario for SAT changes in the second half (1950-99), supporting previous results. It is demonstrated that the Bayesian decision results for global mean SATs are largely insensitive to both intermodel uncertainties and prior probabilities.

Do you think there is something wrong with study or you are going to pretend that it doesn't exist again?

A little Googling finds a [more complete version of Alex's quote](http://www11.hrdc-drhc.gc.ca/pls/edd/SP_AH_676_01_05_434009.htm):

>"For a number of reasons, tests of significance can sometimes be misleading... One of the more interesting problems in this respect is the fact that almost any parameter can be found to be significantly different from zero if the sample size is sufficiently large. (Almost every relevant independent variable will have some influence, however small, on a dependent variable; increasing the sample size will reduce the variance and eventually make this influence statistically significant.) Thus, although a researcher wants a large sample size to generate more accurate estimates, too large a sample size might cause difficulties in interpreting the usual tests of significance... One must ask if the magnitude of the coefficient in question is large enough for its explanatory variable to have a meaningful (as opposed to "significant") influence on the dependent variable. This is called the too-large sample size problem. It is suggested that the significance level be adjusted downward as the sample size grows..."

Kennedy is making the same point about practical significance versus statistical significance that I made in my post. Did you read it, Alex?

Tim Curtin: "To compare only installed capacity is seriously misleading: what is windmills' share of annual output of GWh in say Spain as % of its share of installed capacity?"

I recall a newspaper article that said Spain's wind generators recently set a record of generating 27% of demand at some point in time. It didn't say what time of day that was but for rule-of-thumb purposes I'll assume it was at the time of peak demand. It also said the wind generators had generated 9% of GWh in the previous year. On that basis if they could install enough wind generators to supply 100% of demand when they are operating at full power, then they may be able to supply 33% of GWh. 33% is only 33% but that is a good start and elctricity supply authorities are considering pumped hydro schemes independently of wind energy that would allow wind energy to supply more than 33% of GWh relatively economically.

By Chris O'Neill (not verified) on 17 Apr 2007 #permalink

Here's the wiki on Lindley's paradox:

http://en.wikipedia.org/wiki/Lindley%27s_paradox

I don't know how anyone can say whether it has a small or large practical effect in any given instance without first evaluating the dataset. Unless we assume Sinclair is lying, it sounds like he runs into situations where it matters on a regular basis.

FWIW, IMO there does seem to be a fair amount of evidence for anthropogenic warming, enough we should be at least be taking non-economically-destructive action, though it would be more convincing if we were at a solar minimum. But I also think that there is way too much apocalypticism out there (I'm looking at you Al Gore), often from the same people who deride Bush's "politics of fear."

Al gore is right down the middle of the road as far as I have read. If you want catastrophism, try Lovelock. Oddly enough almost nobody is taking him seriously.

Davidson,

Under what circumstances can Lindley's paradox have a practical effect for N=78, or N=19, for time series?

What magnitude of 'broadening' of the confidence intervals would one expect for N=78, or N-19?

Do N=78, or N-19, constitute "n tends to infinity" in a practical sense?

Well. I have no dog in this fight, however it calls to mind exchanges I had with fellow business students in the later 1990's early 2000's - wherein "dumb" old me (with a bankruptcy law - forensic accounting background) could not understand how the, then, exciting new business models for internet businesses worked. I judt could not understand how the valuation for such money losing enterprises could be explained by the numbers. I cannot tell you how many smug, polite, head-shaking responses I received. "You just don't get it." they all told me. Well, they were right. I did not "get" it as it was not to be "gotten". The entire model was fictional. The resort to personal inquiry i.e. "why don't you get this?" was a dodge as the speaker HAD NO ANSWER. So they turned it back on me. I see that in the above exchange. It seems that this report has come down ex cathedra and a definitive supporting statement need only reference that it as come from a college of scientific cardinals, who "know" these things - no need to look behind that curtain! Repeating, louder each time, that the Report has come out! or that It comes from Knowledgible Persons! hardly amounts to an explaination or defense of how the cited provisions were arrived at. Perhaps Mr. Lambert has reasons to dismiss Mr. Davidson - but viewing this exchange it seems, I note respectfully, that Mr. Davidson has a question about data and Mr. Lambert is either unwilling or unable to answer it - hardly confidence inspiring.

By Californio (not verified) on 17 Apr 2007 #permalink

guthrie,

Compare Gore's 20-foot flooding scenarios in "AIT" with the IPCC's estimates of 23 inches. It's as bad as if Dick Cheney were going around claiming Saddam was about to nuke half the world's major cities.

It's not Type I, Type II, or III; IMO it's OCD. NOt that I know _anything_ about statistics, but this comment section's full of data.

TallDave the IPCC's 23 inches number doesn't include accelerated melting. Here's another number that mention that includes melting:

>The last time the polar regions were significantly warmer
than present for an extended period (about 125,000 years ago), reductions in polar ice volume led to
4 to 6 metres of sea level rise.

6 metres is the same as Gore's 20 feet.

Californio, the IPCC assessment 0f 90% probability is supported by a detailed report which relies on a whole pile of peer-reviewed scientific papers. I've included an abstract and link to just one of those papers. Sinclair just pretends that none of this research exists.

TallDave,

Actually, the AR4 estimates range from 0.18 to 0.59 meters by end of century, EXCLUDING dynamical ice changes.
Dynamical ice changes are being observed, and are not well understood, so their effects were not calculated - but they are almost certain to increase these estimates, not decrease them.

Al Gore stated that IF the greenland and antarctic ice shelves collapse (ie major dynamical changes) we could get 20 feet. This is true, and it was presented with the appropriate qualifiers.

Dano: "Scientists publishing hundreds if not thousands of papers relating their empirical findings."

Would these be the ones you're talking about:

Oreskes research

"Researchers who tried to replicate Oreskes findings came up with quite different results. Searching the same database using the same keywords, Benny Peiser, of John Moores University, found 1,117 peer reviewed publications with abstracts. In contrast to Oreskes, he found that:

Nearly three times as many studies (3 percent) either rejected or doubted that humans are a cause of the current warming as those that explicitly endorsed the "consensus view" that humans are causing warming (1 percent).

Another 29 percent implicitly accepted the consensus view, but most focused on the projected impacts of climate change rather than its causes.

Two-thirds of all of the studies either made no mention of human influence or dealt with methodological issues, possible responses to climate change or natural factors that contribute to it."
- - - -
"The number of scientists who strongly disagreed with the consensus view (10 percent) outnumbered those who most strongly supported it (9 percent).

Contrary to Gore's claims, 55.8 percent is hardly as strong a consensus as science ever produces about a theory."

From another site:

"She got her search terms wrong and thought she was looking at all the articles when in fact she was looking at only 928 out of about 12,000 articles on "climate change."

Coleen: If you're still here. 1) "global warming is a scientific theory largely supported by the research." Global warming is not a theory. It is a name applied to observation of data collected and statistics applied to those data; some good, some bad. Theories regard the causes of man-made global warming, which is to what I think you actually refer.

On that point, AGW is not largely supported by research and, in fact, several alternative theories regarding the various natural causes are just, if not more, supported by rigorous research. 2) Your analogy falls apart because you imply that your choice (i.e., saving lives vs. sacrificing your boat) is a given. That is, it is known that one of the two outcomes must occur. On the other hand, the efforts to curb man-made CO2 levels -- regardless of their proven minimal impact on worldwide concentrations -- are not known to have a significant, if any, effect on global warming. Therefore, you are willing to "sacrifice" for the so-called greater good, "just in case." DDT was banned in the absence of real data and millions have died uneccesarily from malaria due to an overreaction to bad and made up data presented in a novel. A similar outcome is possible from efforts to curb GW; that is, we could greater weaken strong economies and wreck attempts at growth in the 3rd world by taking ineffectual and, possibly, uneccsesary, action.

Better to know the facts then to act on presumptions.

Lee, I agree that Lindley's paradox applies to large data sets and not small data sets (like you describe). I've even said so above. The IPCC claim to have a large data set. They claim to have a 90% confidence. With a large data set 90% may or may not be statistically significant - this depends on the sample size. In addition, I would be very sceptical of a result showing AGW with as few as 19 observations - to be frank, I'd be sceptical of any result with n = 19. Climate needs to be evaluated over a long time period, which is why issues such a Lindley can be important.

By Sinclair Davidson (not verified) on 17 Apr 2007 #permalink

DDT was banned in the absence of real data and millions have died uneccesarily from malaria due to an overreaction to bad and made up data presented in a novel.

DDT was never, ever banned, as has been discussed ad nauseam on this very blog. Yet somehow there's always a commenter ready to trot out this myth.

Your other claims are similarly misinformed, such as:

...several alternative theories regarding the various natural causes are just, if not more, supported by rigorous research.

How about a reference to an "alternative theory... supported by rigorous research"? Preferably something peer-reviewed. It would be nice to have something substantive to rebut.

"With a large data set 90% may or may not be statistically significant - this depends on the sample size."

Would someone please tell me what the hell this sentence means?

A 90% confidence interval is, well.. a 90% confidence interval. It is statistically significant at the 90% confidence level. The interval will vary depending on the distribution of observations and the sample size, but it will be the 90% confidence interval - stating that it might or might not be significant depending on the sample size is jibberish, a statement in which I can find no meaning.

Now you might try to claim that the 90% confidence interval was incorrectly calculated - well, you did try to claim that - but if so, you would need to show that something specific to this data set was neglected or done incorrectly. You just admitted that the Lindley effect yo keep citing is not applicable to these confidence intervals for this sample size, so your argument is left floating in the aether, with no target - and this jibberish about a 90% interval perhaps pot being significant based on sample size is no improvement.

Kennedy is making the same point about practical significance versus statistical significance that I made in my post. Did you read it, Alex?

Practical v statistical significance is a separate problem. Too-large sample bias (Lindley's paradox) is an issue of statistical significance even before we get to practical significance.

Tim - you really struggling here. The distinctions you're making are getting finer and finer. Judge et.al make the point "For a given significance level the probability of a Type I error is held constant whatever the sample size, and the probability of a Type II error declines as T increases. This situation favors H0 when T is small and favors H1 when T is large. ... the significance level would need to be a decreasing function of sample size".

If the IPCC have a large data, as they claim, 90% may not be statitically significant. This is set out in textbooks, like Judge (see my quote above) and Kennedy (see Alex above).

By Sinclair Davidson (not verified) on 17 Apr 2007 #permalink

I think Tim is toast here.

By Husky_Jim (not verified) on 17 Apr 2007 #permalink

Sinclair, again, what the hell does this mean:
"If the IPCC have a large data, as they claim, 90% may not be statistically significant."
You have read the summary, and without having read the report, you are throwing hypothesized issues, issues for which you have NO DATA and NO ANALYSIS.

I could just as easily read a summary of something you've done, and then say 'well, they may not have tested to see if the data meets the assumptions of the methods they used, or hell, they may not have tested assumptions that might or might not be relevant to this report, and if they didn't, the analysis might not be valid, so don't trust Sinclair's work."
That criticism would be precisely as valid as the one you are blowing here.

I'm still going through my undergraduate econometrics library. It is a lot of fun.

This latest quote is from the book I used as an undergraduate - Maddala, G. (1992) "Introduction to Econometrics", Second Edition, New York: Macmillan.

In case anyone is in any doubt - this book is an introduction to econometrics. Hence the title. On page 32, Maddala says:

"The problem with a preassigned significance level is that if the sample size is large enough, we can reject every null hypothesis. This is often the experience of those who use large cross-sectional data sets with thousands of observations. Almost every coefficient is significant at the 5% level. Lindley ["A Statistical Paradox", Biometrika, 1957: 187-192] argues that for large samples one should use lower significance levels and for smaller samples higher significance levels. Leamer ["Specifiation Searches: Ad Hoc Inference with Non-Experimental Data", New York: Wiley, 1978] derives significance levels in the case of regression models for different sample sizes that show how significance levels should be much higher than 5% for small sample sizes, and much lower for large sample sizes."

By Alex Robson (not verified) on 17 Apr 2007 #permalink

Lee, I am not the person proposing AGW as a hypothesis. The IPCC have the job of evaluating the evidence. They make claims, and I am checking those claims. The person who makes the claim needs to produce the evidence. The SPM purports to provide a useful summary, and I do realise that summaries are incomplete. This summary, however, is too incomplete. With the amount of evidence and data the IPCC claim to have, 90% confidence is poor evidence, not good evidence. As I've said above, did they think they were preaching to the choir?

By Sinclair Davidson (not verified) on 17 Apr 2007 #permalink

Sinclair, you have thrown out a statistical issue that may or may not be relevant to this, with no evidence that it is in this case, and call that criticism?

And you still have not answered - what does this mean?:
"90% may not be statistically significant"

Lee, this isn't the only issue Alex and I addressed. Tim in his argument and post chose to concentrate on this aspect of our IPCC criticism. This is one sentence in our IPA Review article, and we don't even make that argument in our Australian Financial Review op-ed. So most of this thread is about 31 words, in a 1500-odd word article.

The answer to the question is, the IPCC may have failed to demonstrate/support/show AGW.

By Sinclair Davidson (not verified) on 17 Apr 2007 #permalink

Sinclair, you have been defending that sentence in the context of the AR4 SPM for this entire thread. Now you minimize it and point to other unspecified arguments?

And once again, what the hell does this mean?

"90% may not be statistically significant"

Lee.
Asked and answered. Google Lindleys paradox and look it up if you can't understand it. From my memory Lindleys paradox answers it well.

By Husky_Jim (not verified) on 17 Apr 2007 #permalink

Tim Curtin

Actually those are costs per GWhr. The capacity utilisation rates aren't changing, they are what they are-- so they are not impacting costs of wind power (actually, we are getting better at understanding local winds, so we are making some improvements there). Costs are falling because of learning curve and scale effects in the manufacture and installation of wind turbines.

(capacity utilisation or load factor varies by technology. Hydro c. 50%, nukes as low as 50% and as high as 90%, coal fired around 70%, gas fired around 90%. There is a big difference between the 'capacity credit' that the Grid gives you for constructing capacity, and the actual Load Factor that you run-- the former is typically lower, especially in the case of wind and nuclear (because their downtime is not predictable)

The answer in the case of Spain is just under 10% of all generated electricity.

Steve

Agree there is an issue about CFLs and a carbon price would be better than the current subsidy approach to nuclear power and to wind power.

However, since we don't have that carbon price, we can't wait around. The wind industry has been created by government effort over the last 20 years (a drop in per Gwhr energy costs of something like 60-70%). Which was true of the microelectronics industry, the jet aircraft industry, the satellite industry and the internet. And of course the nuclear power industry is entirely a creation of the Cold War and government subsidy (Hyman Rickover's submarines and then the subsidies pumped into civilian nuclear power). It's also broadly true of the pharmaceutical industry (which exists on basic science and scientific training done by governments and universities).

On lightbulbs and other energy saving devices, there is ample evidence that it is not *just* a quality of light issue. I can tell you that in Canada, or the UK, there is widespread ignorance about these devices, and they are not in use in many settings where they could be (offices, communal corridors etc.).

On energy conservation generally the sorts of things I talked about, that consumers and businesses are immune to economic logic because of information problems, transactions costs problems, split incentive problems and 'hyperbolic' discounting, prevail.

California has proven you can do something about this.

Chris O'Neill

There is a wideranging argument about just how big wind can be of a national power consumption pie.

The central problem is wind is not 'despatchable' ie responsive to grid demand and electricity cannot be cheaply stored.

Some countries (Spain would be an example) have a lot of potential for pumped hydroelectric storage. Pump the water up in the night when the wind is blowing and demand is low, and run the generators during peak times. Ontario (which is quite flat) is looking at doing that in disused mines.

The UK would have great difficulty building that level of resource (anything that threatens flooding land in the UK starts a fight, especially in Scotland and Wales, if it is to the benefit of their Sassenach cousins).

West Denmark 'cheats' in a sense, by being tied into the German and Scandinavian grids. So when there is too much wind power, they export it, and too little, they balance load off hydro power in Scandinavia and coal and nuclear in Germany.

In a more isolated grid, like the UK, this is a lot harder.

A 'smart grid' which can draw in power from Combined Heat and Power and backup generators, and also which can restrict peak demand in some ways, would be helpful. But might take decades to implement. However Ontario operates an electricity tariff which allows the utility to shut off air conditioners, washing machines etc. for 30 minutes every 2 hours. That is a measure, I think, of the way things are going-- California is working on similar policies (or may have them).

At the moment, there is reasonable certainty an electricity grid can take 10% wind power (by consumption ie GWhr). The capacity credit for the UK grid from the National Grid Company is 20%-- 1GW of wind displaces a requirement for 200MW of other capacity (at a theoretical 100% load factor, but nothing runs at that, so say 200/0.9=222MW of gas-fired).

Probably the UK grid can take 20% (if we can get the planning permission for the sites-- we have some of the worst delays in the world on this). That would also be true, I suspect, of Texas (which is basically isolated from the rest of the US grid, and has strong and constant winds).

Whether we can get beyond that is uncertain (but see 'smart grids').

I also have considerable hopes for 'local wind' and 'local solar'. With a little tweaking (a 25 volt DC domestic service, say), a house could be run, most of the time, on a small vertical axis windmill and some storage batteries.

By Valuethinker (not verified) on 17 Apr 2007 #permalink

Alex: I'm still going through my undergraduate econometrics library. It is a lot of fun.

I'm sure it is. But you evidently haven't found anything to support your claim:

"As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified."

None of the texts you have cited so far supports that.

By Kevin Donoghue (not verified) on 17 Apr 2007 #permalink

It's kind of fun to see the people who don't know the difference between a probability estimate and a confidence interval go all twisty-turny like a twisty-turny thing.

I'll second that, Zarquon -- it's pretty absurd to see something like this:

With the amount of evidence and data the IPCC claim to have, 90% confidence is poor evidence, not good evidence.

in light of Tim clearly pointing out that the 90% was a probability estimate, not 90% confidence. I'm wondering if the posters making this argument even read Tim's actual post; I'll quote it for their sake:

They have also confused the IPCC's more than 90% probability (what is the probability that most of recent warming is man-made?) with 90% confidence on a hypothesis test (what is the probability that a model with only natural forcings could produce half as much warming as observed?).

Sinclair, Alex, is it true that you did something with a temperature scale running to near absolute zero and then claimed you were making a point about the climate of Earth? That sounds a little scandalous to me. I think that economists and novelists oughtn't be too presumptuous about the value of their deep thoughts to the field of climatology, and I'd hope you'd agree.

You say "There is an even greater problem with the analysis. The IPCC provides a breakdown of seven extreme weather events ... Somehow this all adds up to 90 per cent". In this case you are certainly confused because there is no way that your quote of the IPCC:

"Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations."

should mean that the consensus position of the world's recognised climatologists need in any way involve a "90 per cent" certainty of anything at all regarding those particular extreme weather events. I think this confusion alone would warrant a clarification of the wording in your article.

You are right that people should discount "hysterical commentary".

Leaving your article aside, just what do you think the IPA would accept as being a sensible free market approach to anything which threatened "to despoil the planet and leave an environmental mess for future generations"? I'm interested.

Sinclair, Alex, is it true that you did something with a temperature scale running to near absolute zero and then claimed you were making a point about the climate of Earth? That sounds a little scandalous to me.

What's even more scandalous is that Tim suggests we did do that. We show two diagrams, first the temperature anomaly and second the temperature level in degrees centigrade. The first figure has a scale from minus 0.8 to plus 0.6 and the second has a scale from 0 to 30. Most Review readers would be familiar with temperatures in this range and might even experience temperature variation in that range (if not more and less).

We stand by our criticisms of the IPCC SPM - we will not modify anything. We have answered all the substantial comments posted here including quoting from introductory textbooks.

I cannot speak for the IPA, but I would have thought before endorsing government action it would be sensible for there to be some proof that human actions were despoiling the planet. As you can imagine, I'm not convinced by the SPM, but will read the remaining reports over the course of the year.

By Sinclair Davidson (not verified) on 17 Apr 2007 #permalink

Your article Sinclair is badly confused on the relationship between those extreme weather events and the matter of the IPCC's 90% certainty of something else, but it's your article.

Now we all deal with threats all the time despite never having "proof" that calamity would necessarily befall us did we not take out life and car and house insurance, try to cut back on our smoking and drinking and overeating, often avoid certain areas of our cities at certain times, learn to swim before diving in the deep end, etc etc etc.

Why would the risk that we may "despoil the planet and leave an environmental mess for future generations" be of less interest to someone or the IPA than is their car insurance? It wouldn't, so I wonder what you would be willing to do today.

I agree. People try to be sensible. When buying insurance I shop around. I don't buy the most expensive insurance. There is some probability that my car may get stolen (this has actually happened to me) and my house robbed etc. Is there a probability that we're despoiling the planet? Probably. Is it a certainty? No. Even the IPCC think it's only 90%. So I would like more information. That's a plausible thing to do. I read the information broucher before buying insurance, why should any other decision be any different? The IPCC SPM brief is to provide that information; Alex and I are underwhelmed. So we'rem not buying, and we've told others why we're not buying. They are free to believe us or not. There is a market for ideas.

By Sinclair Davidson (not verified) on 18 Apr 2007 #permalink

My post only contained one paragraph about Sinclair and Alex's misrepresentation of what elementary stats texts said. The reason why there has been so much discussion of this point is that it's the only one that they have been willing to discuss. The main point is referenced in the title -- their denial of the existence of attribution studies. Here's what I wrote again:

>Despite the SPM including a graph that fills an entire page showing the results of tests of models, Davidson and Robson claim that it is likely that the IPCC doesn't have a testable model. Davidson and Robson are taking denial to another level. They have also confused the IPCC's more than 90% probability (what is the probability that most of recent warming is man-made?) with 90% confidence on a hypothesis test (what is the probability that a model with only natural forcings could produce half as much warming as observed?). The hypothesis tests that the IPCC refers to achieved levels of confidence greater than 95%.

Neither Alex nor Sinclair have a response to this. I wonder why not?

Now let's look at this again:

>As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

Elementary stats texts do not say that you have to increase significance levels with large samples and they must definitely do not say that you should reject the alternative hypothesis if the specified level of significance is not achieved. Alex and Sinclair have now resorted to quote doctoring to try to make it appear that they do. In the quotes below I have added in bold the words they left out from their quotes.

Sinclair's quote of Judge et al

>"For a given significance level the probability of a Type I error is held constant whatever the sample size, and the probability of a Type II error declines as T increases. This situation favors H0 when T is small and favors H1 when T is large. **In contrast, the Bayesian approach treats both errors symmetrically and favors neither hypothesis as T increases. For the sampling theory effect to be achieved within the Bayesian framework, we would need to make the prior odds ration a decreasing function of sample size. Similarly, for the Bayesian effect to be achieved within the sampling theory framework,** the significance level would need to be a decreasing function of sample size".

Judge is contrasting Bayesian and frequentist hypothesis testing. He is not, as Sinclair tried to make you think with his quote doctoring, advocating that the significance level needs to decrease with bigger samples. Compare the original with Sinclair's version and ask yourself if he was being honest.

Next we have Alex's quote of Kennedy. Bolded are the bits he left out without even an ellipsis:

>"One of the more interesting problems is the fact that almost any parameter can be found to be significantly different from zero if the sample size is sufficiently large. **(Almost every relevant independent variable will have some influence, however small, on a dependent variable; increasing the sample size will reduce the variance and eventually make this influence statistically significant.)** Thus, although a researcher wants a large sample size to generate more accurate estimates, too large a sample size might cause difficulties in interpreting the usual tests of significance. **McCloskey and Ziliak (1996) look carefully at a large number of empirical studies in economics and conclude that researchers seem not to appreciate that statistical significance does not imply economic significance. One must ask if the magnitude of the coefficient in question is large enough for its explanatory variable to have a meaningful (as opposed to "significant") influence on the dependent variable.** This is called the too-large sample size problem. It is suggested that the significance level be adjusted downwards as the sample size grows**; for a formalization see Leamer (1978). See also Attfield (1982) Leamer would also argue that this problem would be resolved if researchers recognized that genuinely interesting hypotheses are neighbourhoods, not points.**

He says (in the bit Alex omitted) "that statistical significance does not imply economic significance". But Sinclair claims that Kennedy is not writing about "Practical v statistical significance". Note further that he states the problem does not apply if the hypothesis is a neighbourhood, which is, of course, the case here. (Hypothesis being "most of recent warming is man-made".)

Last, we have Alex's quote of Maddala. Again, bold is the bit he left out.

>**The usual procedure that is suggested (which is called the Neyman-Pearson approach) is to fix α at a certain level and minimize β, that is choose the test statistic that has the most power. In practice, the tests we use, such as the *t*, χ2, and the *F* tests.**

>**There have been some statisticians who disagree with the ideas of the Neyman-Pearson theory. ... There are some statisticians who think that the significance level used should depend on the sample size.**

>"The problem with a preassigned significance level is that if the sample size is large enough, we can reject every null hypothesis. This is often the experience of those who use large cross-sectional data sets with thousands of observations. Almost every coefficient is significant at the 5% level. Lindley ["A Statistical Paradox", Biometrika, 1957: 187-192] argues that for large samples one should use lower significance levels and for smaller samples higher significance levels. Leamer ["Specifiation Searches: Ad Hoc Inference with Non-Experimental Data", New York: Wiley, 1978] derives significance levels in the case of regression models for different sample sizes that show how significance levels should be much higher than 5% for small sample sizes, and much lower for large sample sizes."

Alex made it appear that Maddala said that you should use lower significance levels for large samples when, in fact, he said that the usual procedure was to use fixed levels.

To summarize, none of the text cited by Alex and Sinclair supported their claim that:

>As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

So Alex and Sinclair resorted to quote doctoring to make it look like that they did.

And none of this applies to the SPM in any case, because the attribution studies don't use large samples, some of the attribution studies use Bayesian methods, the significance levels were greater than 90%, and the null hypothesis was not a point.

It's also telling that they don't mention changing the vertical axis of the temperature graph. Fortunately, this is also dealt with in an elementary text: How to Lie with Statistics.

Wait a minute, are we talking about Sinclair Davison being a professor of something, and thus a respected member of society?

Also, he appears unable to see that there is not a market for scientific ideas comparable to that for, say, dieting fads.

I'm shocked, I tell you.

I don't really see any issue here. What exactly is the discussion about? That the Earth's trend is towards warming based on the data we have and that the recent abberations are atypical and meaningful rather than measurement sophistication or some other factor? That we can indeed compare ice cores in Antartica to air in Hawaii? Or that we can prove or disprove any of it. Seems like a lot of opinion on cause/effect going around.

The global average temperature rose from 13.5C to 14.4C on a 5 year average from 1865 to 2000, but who's to say one or the other is too cold or too warm?

So if the average is about 14C, what happens if it went down to 9C or up to 19C on the average? Is it bad to be one or the other?

Why can't we graph out the GHCN-ERSST data for 1880 to 2006 of -.2 to +.3 (low -.73 1793 High +.6 2002) on a scale of +/- 5C (What's 5C among friends?) One could say a puny +/-1C isn't meaningful enough to purposely make the trend look so scary by not using +/- 2.5 or 5 or 10 degrees.

What's a troublesome rise or fall? I think it should be graphed on that scale. What is that number? How is it decided? Who decides it?

My main question is; what's the margin of error in the readings? We should try and factor that out as an issue in this discussion.

We've gone from +.6 to +.3 in the last 4 years -- is that a big deal? Is it in the margin of error? Is it any more or less troublesome than +.27 in 1942 to -.38 in 1950 or -.38 in 1950 to +.27 in 1958??

http://www.ncdc.noaa.gov/gcag/gcag.html

By Robert S. (not verified) on 18 Apr 2007 #permalink

The big deal is that apparently you have read stuff, but appear unable to decide what it means.
What it means is that we are looking at around 3 degrees of warming above the natural background from 50 years ago, over the next century. This would be higher than any period for thousands of years.
The effects are expected to be unpleasant for ecosystems and lots of people.

Well, really, I have decided. It means little or nothing. I know what it's supposed to mean, but I'm not convinced the apparent trend will continue. Even if it does, which yes, it might, I'm not convinced that an average of 17C is "bad". It's all conjecture right now. We could just be measuring better (or worse).

Look at the facts; in 125 years it's only gone over .7 off average once. -.73 in 1893 The highest has only been +.6 And since then, it's gone back down slightly lower than where it was in 2001 when we started spiking. We've only gone over +.3 like 6 periods in the last 20 years and we've been there before: early 40's and late 50's. I just don't see what all the fuss is about.

Now don't get me wrong, I'm not denying the Earth is warming. But yes, I'm not accepting it either. I'm neutral about it. Maybe it is, maybe it isn't. I think there's a lot of questions that need to be asked and answered better than they are currently (rather than "tends to" or "appears if" or "probably is):

Is this just an apparent warming due to margin of error, change of measurement methods or something else?
If not, is it real warming due to some external factor (clouds, sun, cities) other than CO2?
If the warming is real (and it certainly looks as it is, if we accept the measurements are correct, valid and out of a margin of error within the sampling interval), can we make more than a casual link between the warming and CO2?
Can we do enough to reduce CO2 to stop the warming either way?
If so, is it worth the money to do so?
Regardless, is a x% rise (or fall) in global temperature good or bad?

How bad is 15C vs 13C? Given the -.73 to +.6 variation, I'd say this doesn't look like much to me. Especially since the trend is now down. I suppose we'll see. I myself will hold judgement for a few years.

Maybe I'll worry about it when we go over +1 or +2 Trouble is, nobody will know it, as it appears we'll all be dead of old age before it does.

By Robert S. (not verified) on 18 Apr 2007 #permalink

By the way, yes, I do agree the trend line from 1880 does look scary, but then again, I think the scale is too low. Plus we're on the edge of the graph, a bad place to be (as anyone trying to guess future stock prices based upon past stock prices has found out in the short term.)

How do we know the measurements are not just more accurate every 5-20 years? Or that atmospheric aerosols are masking what's really going on one way or the other?

As the IPCC said:
While the radiative forcing due to greenhouse gases may be determined to a reasonably high degree of accuracy... the uncertainties relating to aerosol radiative forcings remain large, and rely to a large extent on the estimates from global modelling studies that are difficult to verify at the present time.
(Although I wonder why they didn't specific what "reasonably high" was as a percentage.)
In any case, what will the continued efforts by the EU and the US to reduce particulate emissions from vehicles do to the weather?

I just don't see why anyone thinks this is a big deal. We can increase fuel economy, reduce vehicle and industrial emissions, recycle, plant trees, and clean the air -- and see what happens. Surrender is a perfectly acceptable option. No, I meant to say, why spend billions on burying CO2 in the ocean? Is it making a big dent in anything? Can't we spend the money more effectivly, like on combating nuclear proliferation and AIDS and starvation and disease instead? It just doesn't seem like a very good decision on what to do with limited resources.

Graphing 2000 to 2006 only has an 11% significance. 1995 to 2006 76% (and it doesn't look so bad) So I'll come back in 2010 and we can discuss 2000-2010 at that time.

By Robert S. (not verified) on 18 Apr 2007 #permalink

Tim, quote doctoring is a serious allegation. Can you make an argument for how our quoting changes the meaning of the original texts, or have you just found that we quoted the important aspects of the text? Afterall I quoted nothing from the previous 305 pages of Judge etal.

By Sinclair Davidson (not verified) on 18 Apr 2007 #permalink

Robert, have you actually read anything about the science behind this?
Ignore the stats for now. Do you have any comprehension of what temperature rises mean in real life?

What on earth are you blithering on about with regards to cleaning up our emissions and surrendering? Your not making any sense to me.

I already explained how you changed the meaning. Here's what I wrote about your doctored quote from Judge:

>Judge is contrasting Bayesian and frequentist hypothesis testing. He is not, as Sinclair tried to make you think with his quote doctoring, advocating that the significance level needs to decrease with bigger samples. Compare the original with Sinclair's version and ask yourself if he was being honest.

Do you have any explanation to offer for your misconduct?

Graphing 2000 to 2006 only has an 11% significance. 1995 to 2006 76% (and it doesn't look so bad) So I'll come back in 2010 and we can discuss 2000-2010 at that time.

You know, I like that.

Good idea: all the denialists should do that. Just go away until 2010. Buh-bye! Buh-bye now!

Best,

D

Dano: Thanks for the vote of confidence! lol
But I'm not a denier. I'm a fence sitter. I never said it's NOT happening. I say the evidence, such as it is, is not clear enough for the level of time, energy and money we're putting into it. The trendline is clear; if the measurements are accurate and complete enough and are made the same over time (which I'm not totally convinced they are, obviously), it's warming. Certainly, there's enough data to tend to point to a general warming trend. I'm still curious as to the margin of error in the measurements, care to share some?

In any case, I just can't get excited about .05C per decade, if that's even out of the margin of error. Whichever it is, in the margin of error or not, sorry I don't agree with you on the importance of it.

So, last year, it went down .2 or so; does that trend continue, or does it spike up again the next year? And no matter what it does, what does it mean? To me, not much.

By Robert S. (not verified) on 19 Apr 2007 #permalink

Guthrie: I've read enough of it from many of the "both sides" to not have enough faith in all the models, nor many of the predictions. A lot of them seem like guesses. I've read a lot of the IPCC stuff, there's a lot of wiggle statements in there and I think many times everyone's jumping to conclusions. I also am rather of the mindset the predictions are mostly far too pessimistic.

Now, see, I'm not saying we shouldn't do anything at all about it, I'm just saying we have to approach it in a calm, logical manner and maximize the results we get for whatever it is we do. I'm not convinced sequestering is the major answer, or even the main one, nor that CO2 is the only culprit (at least not from the emissions only standpoint) or what all the feedback loops are doing or are going to do. Yes, I know the effect lags by a great number of years. But I don't think there's enough of a link that's been proven to take drastic action (yes, I know things can happen fast and without warning). But it's just not anything I see. Where was the "Super El Nino" last year, for example.

I also look at the huge population growth over the years; billions breathing out CO2, building cities and removing vegetation, farming, creating polution, driving vehicles that expel a lot of stuff... The other is the number of animals (breathing, um methane, solid waste) that goes along with the number of people.

I would get more concerned over the temperature effects over the landmass of the U.S. 1880-2005 (-4.5 to +2) or Europe (-4 to +3.5) But those charts, even though trending up, are not only all over the place, the trendline is only from -.1 to +.1 and I'm not too worried about a .2 variance over 126 years. For a 33% increase in CO2 over that time period? I just don't get upset over it. Sorry.

I really tend to think we're just measuring it better (or at least differently (and notice I said tend to). And there are far too many variables to really know, at least in my opinion. What is our margin of error? I never hear about the exactness of we're measuring, when we're talking about rising an average of .005 a year -- I know it's not a perfect measurement (although I do admit that as long as it's been trending up, it probably removes a lot of that error given the trend) but there is something.

If I were everyone, I would worry more about what the rapid industrialization of China and India, as well as what's going on in Russia, is going to do to the temperature, environment and economy of the world, rather than spending billions of dollars to sequester carbon for what I see is a very low rate of return.

That's what this is all about, not AGW, but rather what we perceive as to how bad it is, and how to figure out what to do about it.

Sorry about the surrender thing, C3PO says it in Empire Strikes Back: "I really don't see how that's going to help. Surrender is a perfectly acceptable alternative in extreme circumstances...."

I just don't think the circumstances are all that extreme. Obviously many here disagree with that.

Look, this probably sounds insulting, but merely saying
" there's a lot of wiggle statements in there and I think many times everyone's jumping to conclusions."
without any references, without any suggestion of why, in effect relying upon your gut instinct, is neither how you do science or carry out a reasoned argument.
Can you tell us precisely what it is you have trouble with?

Bear in mind that the science is not nailed down to tha accuracy of quantum mechanics (21 decimal places I believe), therefore there are caveats, and anyway good scientists always put in caveats. It might be that your misunderstanding comes from miscommunication.

Anyway, people and animals breathing in and out does'nt matter, really. We consume food and breath out CO2, things tend to balance out. A rabid anti-science anti-environmentalist once claimed that we could live for thousands of years if all the plants immediately died. I did some rough calculations, and they were correct, even without plants to recycle our CO2 we could live for thousands of years before having any trouble. Of course they didn't think about whether we would like to live in a world without plants.

Anyway, your comments do demonstrate that you have not actually understood the science behind it. For example, the 33% increase is mostly within the last 50 years, not 126. Secondly, we know pretty well what caused the trends in the past century or two, and all that is around to cause our current trends, is our fault because of CO2. REmember that there are other influences on the climate than just CO2.

Why do you think we are measuring CO2 differently? Have you heard of the Keeling curve? Do you know what methods were used 100 years ago, and why the modern infra-red method is much much better? Until you understand what I am talking about, you are in no position to throw around thoughts such as "I think we're just measuring it differently".

Some posts about measuring it:
http://rabett.blogspot.com/
Almost half way down, a post called "Found in the margins"

Or, if you want a more reputable source, try this:
http://www.aip.org/history/climate/co2.htm

Robert S

What IPCC stuff are you refering to or any other literature? I don't recall the papers or sections of IPCC reports describing:

"the trendline is only from -.1 to +.1 ... about a .2 variance over 126 years"

Everyone is entitled to their own opinions but you are not entitled to your own facts.

JP

Now you laying a charge of academic misconduct? Please, go ahead.

So what have we got? Fabrication and misconduct. I think you've been shown up Tim. You challenged me and the best you can come up with is this? Vague allegations of misconduct? Tsk, tsk.

By Sinclair Davidson (not verified) on 19 Apr 2007 #permalink

Guthrie: No worries, not insulted. I know this is not exact, sure. I just remain unconvinced. I'm not trying to sway anyone, just that some of us think differently is my point, and that not all of us deny that something is going on, nor are we saying we shouldn't do anything about it. It's out of science, it's into policy. So.

Yes, I'm aware most of the CO2 is the last 50 years. And I know where they get the readings from and how they get them. In that case, starting 20 years ago, we should have seen bigger temperature changes from the sharp rise (if going from 310 to 400 ppmv is all that sharp) that started in 1960ish. (Myself I'm more worried about the methane.) But come on, IPCC guessing 540 to 970 by 2100? I might see 140 in 90 years (but doubt it) but 570? Does anyone know with any degree of certainty thse three things: a) that's going to happen on that scale b) that will affect the temperature equally and c) the temperature effects will be bad I might buy c but b is ify and a I highly doubt. You don't agree with that assesment, but it's the one I have. Hopefully I'll live to be 135 and see it.

As far as the measurements, I was talking about the temperature readings, on a global scale. And regardless of the IPCC, the fact remains the data looks meaningless to me on the scale, given all the factors. Again, that's just my opinion.

I'm being generic about the IPCC because there's so much in there that bothers me. It's wishy-washy. Well, maybe that's too strong. It's more WGI puts out too much information that seems rather meaningless to me (and in general somewhat overblown and too politically and academically focused) WGII takes that information and makes it too emotional an argument for drastic action. I just don't like the overall tone, nor believe it all. I can doubt it in its entirety, can't I?

Not just a gut instinct, more like a bad taste in the mouth. At least for the TAR; I will admit I haven't ready much of the 4th, it struck me as more of the same. I should read the entire thing, because I could be wrong.

Let me see, well, an example.

Oreskes: "Human activities ... are modifying the concentration of atmospheric constituents ... that absorb or scatter radiant energy. ... [M]ost of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations" [p. 21 in (4)].
4. J. J. McCarthy et al., Eds., Climate Change 2001: Impacts, Adaptation, and Vulnerability (Cambridge Univ. Press, Cambridge, 2001).

This is actually what she cherry-picked to get that, pretty much (and hides the source in the footnote) Emphasis mine:

WGII of the IPCC Technical Summary: Impacts, Adaptation, and Vulnerability

Disclaimer at start of Technical Summary
This summary was accepted but not approved in detail at the Sixth Session of IPCC Working Group II (Geneva, Switzerland ⢠13-16 February 2001). "Acceptance" of IPCC reports at a session of the Working Group or Panel signifies that the material has not been subject to line-by-line discussion and agreement, but nevertheless presents a comprehensive, objective, and balanced view of the subject matter.

{Rather contradictory, as well as seeming to be a debating trick and logical fallacy.}

First paragraph of section 1.2

1.2. What is Potentially at Stake?
Human activities--primarily burning of fossil fuels and changes in land cover--are modifying the concentration of atmospheric constituents or properties of the surface that absorb or scatter radiant energy. The WGI contribution to the TAR--Climate Change 2001: The Scientific Basis--found, "In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations." Future changes in climate are expected to include additional warming, changes in precipitation patterns and amounts, sea-level rise, and changes in the frequency and intensity of some extreme events.

That's what we're supposed to base spending billions of dollars on?

I am simply saying we could better spend the money. I'm not trying to dog anyone out, I appreciate that those are the honest opinions of others that think it is sufficient. Is that fair?

By Robert S. (not verified) on 19 Apr 2007 #permalink

JP: I didn't use IPCC data, I pulled it right from NOAA data figures. You can go graph it yourself here, 1880-2006:

http://www.ncdc.noaa.gov/gcag/gcag.html

I used the GHCN - ERSST Mean Temperature Anomalies.

I admit, I didn't take the time to do an exhaustive comparison with the other data sets, I just chose that one because it came up first. Pseudo-random I suppose.

The Europe landmass is long 0 to 20, lat 44 to 53 Basically the edge of France to Budapest and then Bremen Germany to Genoa Italy

I don't have the long/lat any more for the U.S. chart, but it's basically the four extreme tips of the US on lines that basicially include the entire country trying to minimize the amount of water (although I suppose I could have just used the surface data) I was rather sloppy on that one.

The entire globe starts at .-2 (1880) and ends at +.2 (2006) so it's double the areas I looked at, .4, but much more consistent from year to year. Correct me if I'm wrong, but I believe the error in the measurements is +/- .7

Anyway, I also took the raw data for the globe and charted it on a notional 9-19C graph, just to see what it looked like at the +/- 1 points on what I consider to be a more meaningful scale, assuming if you live in a place that goes from 9 (48 F) in the winter to 19 (66 F) in the summer, what does that low off average of -.73 to high off average of +.6 look like within the 1 degree range of 9-19. Looks pretty meaningless, considering some places go from a winter of -6C to a summer of 38C (for example).

Chart the variation off average of 1880-2006 on a chart of Europe (say) for on a graph from -6 to 38 Can't even see it.

By Robert S. (not verified) on 19 Apr 2007 #permalink

Maybe I am thick. But I see IPCC say (to quote a poster above) that there is a more than 90% probability that most of recent warming is man-made.

But I don't understand how they get such a high level of confidence, when they clearly acknowledge how much is uncertain, for example, the knowledge about forcings.

Perhaps someone more enlightened than me can explain how the IPCC can be so confident about something that they themselves describe as having many uncertainties.

I don't get it.

That's the problem; they don't give a percentage. What the hell does "likely" mean? Or half the other stuff they say, like what is "some extreme events"?

By Robert S. (not verified) on 19 Apr 2007 #permalink

Robert

I have already plotted global and regional temperature anomalies using a variety of data sources, that why your values stood out, they were not consistent with the data. I believe that you made an error in your exploration of the data on the NOAA site. When calender years (January to December) using the combined land and sea data set are plotted over the interval 1880 to 2006, the linear trend (blue line) begins at approximately -0.4 C and ends at +0.2 C. You may not be able to feel 0.6 C, but natural systems can. Take a closer look at the graph, and examine the trend over the last 30 years. Then extrapolate.

You may wish to explore a similar dataset at the GISS website. There are some interesting interactive tools that allow you to explore the spatial distributions of temprature changes. There are also some materials at the GISS site on error in these datasets.

Maybe I am thick. But I see IPCC say (to quote a poster above) that there is a more than 90% probability that most of recent warming is man-made.

They get such a high level of confidence because the theory of AGW is based on well known physical properties, confirmed in lab experiments and confirmed by observations. There are next to zero studies that point to a different cause for warming.

I'd say that the 90-95% is a very safe estimate of the state of the science.

That first sentence should be a blockquote from trevor. The one time I don't hit preview....

I don't think it's fair on the evidence to accuse Sinclair and Alex of dishonesty.
What they've actually shown is that they don't understand either statistics generally or the subject they've commented on particularly (the IPCC) quite as well as they've presumed, and consequently have written nonsense about them. It is true as Sinclair says that there's a free market for ideas out here ... so perhaps I shudder to think of the number of dupes who'll be buying in to this ill-founded commentary. That doesn't cover the IPA which will buy into anything it calculates should please its sponsors, while remaining unable to answer even simple questions about the possibility of free market solutions to important matters (as opposed to the trivial issues that they do try to grapple with).

C'est la free market for ideas however, buyer beware.

Sinclair I commend you on your reasoned and balanced posts.

Please remember though that Tim Lambert is more political than scientific in his conduct so you should expect vague allegations of no substance from him as part of posting here.

guthrie, I agree that it likely they write nonsense because they don't understand statistics, but I've asked Sinclair more than once to explain why he turned this quote from Judge:

>"For the sampling theory effect to be achieved within the Bayesian framework, we would need to make the prior odds ration a decreasing function of sample size. Similarly, for the Bayesian effect to be achieved within the sampling theory framework, the significance level would need to be a decreasing function of sample size".

into this:

>"the significance level would need to be a decreasing function of sample size"

and claimed it supported his claim that:

>As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

I'm hoping he can explain why he thinks that was honest quoting, but he keeps being evasive.

The bots gavotte, and hate it when it doesn't work. The usual result is the Sinclair slide and the Peter M back-get.

Of course, we see it here at Deltoid about once a week. We should number the denialist quibblings, evasive maneuvers (manoevers) and tactics like that old joke about numbering jokes.

Best,

D

Tim you've been asked numerous times how the IPCC reaches its 90% figure and have failed to answer that. We are still waiting. No personal attacks or evasion please.

- I agree. People try to be sensible. When buying insurance I shop around. I don't buy the most expensive insurance. There is some probability that my car may get stolen (this has actually happened to me) and my house robbed etc. Is there a probability that we're despoiling the planet? Probably. Is it a certainty? No. Even the IPCC think it's only 90%. So I would like more information. That's a plausible thing to do. I read the information broucher before buying insurance, why should any other decision be any different? The IPCC SPM brief is to provide that information; Alex and I are underwhelmed. So we'rem not buying, and we've told others why we're not buying. They are free to believe us or not. There is a market for ideas.

Posted by: Sinclair Davidson | April 18, 2007 06:33 AM

Sinclair:

Suppose your car is stolen. You lose your car. You replace it.

Suppose your wife, kids and everyone else you know or have ever met dies. You can't replace them. This because there is a reservoir above the town, but it was a tax rise to strengthen the wall of that reservoir. You voted against the tax rise as 'unecessary', and one day, the reservoir collapsed.

Clearly the insurance policy you buy against the latter, which costs you your car is going to be a very different financial decision than the insurance policy you buy to save your town (or your planet).

I would argue that we need less than 1% chance of dangerous climate change, to justify urgent and expensive action. Because the loss, if you do lose, is potentially so vast.

This is particularly true as reinforcing the wall, in this case, is likely to take at least 50 years.

By Valuethinker (not verified) on 19 Apr 2007 #permalink

The interesting thing, Robert, is that most of the equivocation and comments about not having been line by line approved arise, as far as I can tell, because this is an extremely political arena, with as you point out billions of pounds hanging on what is said and done. Hence the requirements for oversight, and demands that things be gone through line by line, as if changing a couple of words will change emphasis and attitudes.
And what do you know, it's true.
Meanwhile, the science speaks for itself.

Tim, thats Frankis your talking about, not me. I havn't accused Sinclar et al of anything.

According to Robert S., http://www.ncdc.noaa.gov/gcag/gcag.html says that "The entire globe starts at .-2 (1880) and ends at +.2 (2006)".

When I look at the graph, the trend starts at -0.4 (1880) and ends at 0.2 (2006). Perhaps what Robert actually did was take the actual value at 1880 (-0.2) but the value of the trend at 2006 (0.2). When you have a predetermined conclusion, it's an easy mistake to make. (By the way, there wasn't too much global warming from 1880 to 1908, global cooling in fact, and not too much ACO2 either.)

By Chris O'Neill (not verified) on 20 Apr 2007 #permalink

Tim, I still waiting for amplification of the academic misconduct charges you've laid against me. You wouldn't want to deny me natural justice, now would you? Facts, please.

By Sinclair Davidson (not verified) on 20 Apr 2007 #permalink

Sinclair writes:

"Is there a probability that we're despoiling the planet? Probably. Is it a certainty? No".

Clearly, Sinclair you must be living on another planet if you really think that it is not a certainty that humans are 'despoiling' the planet. However, before I engage in banter on this apparent comic book level of understanding, I would like to know exactly what you mean by 'despoiling'. Is this restricted to climate change or does it cover all of the other anthropogenic changes to the biosphere? For instance, other forms of pollution; disruptions in biogeochemical and hydrological cycles; the loss of forests and other habitats; biological homogenization of the biosphere through the introduction of species into non-native ecosystems; overharvesting natural capital. Including any or all of these anthropogenic processes make it patently obvious that humans are 'despoiling the planet'.

By Jeff Harvey (not verified) on 20 Apr 2007 #permalink

Dano wrote: "Good idea: all the denialists should do that. Just go away until 2010. Buh-bye! Buh-bye now!".

This is a great idea, but I'd prefer an even longer time frame - I'd say that the denialists should go away for at least the next 50 years, or until I am dead and gone. Then I won't have to listen to them anymore!

By Jeff Harvey (not verified) on 20 Apr 2007 #permalink

Making the planet uninhabitable for future generations would be despoiling. Enhancing natural attributes is not despoiling.

By Sinclair Davidson (not verified) on 20 Apr 2007 #permalink

Enhancing natural attributes is not despoiling.

A...AHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAAAAAA!!!

HA......HA.....

HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA

Hoo...hoo boy.

Uh...uh...ha...

uh-oh...

HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA

heep...heep...

OK. Some people contribute comments to make us laugh, and I thank you for that Sinclair. Good 'un.

Now, seriously go away until 2010 what is your definition of 'despoil', if you actually have a clue?

Best,

D

Sinclair,

Combining the anthropogenic effects I mentioned above, and based on your definition, humans are clarly despoiling the planet. In simple terms, our species is spending natural capital like there is no tomorrow. This is clearly seen in the loss of groundwater supplies, deep rich agricultural soils and biodiversity. We are spending this capital as if there is no tomorrow. In effect, we are conducting a global experiment on our ecological life-support systems; these sytems are incredibly complex and function in little explored or understood ways. Yet environmental scientists realize that these systems generate conditions over variable scales of space and time that make the planet habitable. Against this background, humans - especially in the overconsumptive ad wasteful develped world - have adopted a slash-and-burn for profit approach to the biosphere. The empirical evidence of the causes and consequences of human activities on nature is massive. Yet you come back at me by saying, 'Enhancing natural attributes is not despoling'. Are you serious?

I assume you are the same Sinclair Davidson that is a business economist in Australia. With no disrespect, what do you know about environmental science, population ecology and other related fields? What do you understand about the human effects on natural systems and on the services that emerge from them that permit humans to exist and to persist? Another business economist, Julian Simon, wrote a lot of nonsense before he died in which it was claimed that the human carrying capacity of the planet is limitless due to the three bulwarks of neoclassical economics: human ingenuity, substitutability, and efficiency (Simon's most laughable quote was to claim that the world has enough resources to feed an ever expanding population for the next seven billion years; at an even limited 1% growth rate human biomass would be expanding faster than the universe; within 700 years there would a person on every square meter of the planet's surface). More recently the same tired theme has been reperated by the likes of Bjorn Lomborg. Neither Simon nor Lomborg has or had any pedigree in the life sciences, which might explain why both dismiss the natural economy in their analyses and focus instead on the material economy, suggesting that humans are exempt from the laws of nature. But the material economy represents a very small subset of the natural economy. Further, as more ecologically minded economists like Geoff Heal, John Gowdy, Herman Daly and others have explained, the three foundations of neoclassical economics that I mentioned are flawed. Brian Czech demolishes them in his book, 'Shoveling Fuel for a Runaway Train'.

By Jeff Harvey (not verified) on 20 Apr 2007 #permalink

"Making the planet uninhabitable for future generations would be despoiling. Enhancing natural attributes is not despoiling."

Ozone, radon, carbon monoxide, nitrogen dioxide and sulphur dioxide are all "natural attributes" of the atmosphere, do you want them "enhanced"?

By Ian Gould (not verified) on 20 Apr 2007 #permalink

Jeff Harvey "More recently the same tired theme has been reperated by the likes of Bjorn Lomborg. Neither Simon nor Lomborg has or had any pedigree in the life sciences, which might explain why both dismiss the natural economy in their analyses and focus instead on the material economy, suggesting that humans are exempt from the laws of nature."

Think of it as a Triumph of The Will.

By Ian Gould (not verified) on 20 Apr 2007 #permalink

Sinclair, I already explained how you doctored the meaning. Yet again. You turned this

>"For the sampling theory effect to be achieved within the Bayesian framework, we would need to make the prior odds ration a decreasing function of sample size. Similarly, for the Bayesian effect to be achieved within the sampling theory framework, the significance level would need to be a decreasing function of sample size".

into this:

>"the significance level would need to be a decreasing function of sample size"

and claimed it supported your claim that:

>As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

Judge is contrasting Bayesian and frequentist hypothesis testing. He is not advocating that the significance level needs to decrease with bigger samples.

I have repeatedly asked you to explain yourself. You have not done so. Yet again, do have any explanation to offer for your actions?

JP: Yes, sorry. Let me be more exact. The -.16 is the 1880 temp and +.28 is the 2006 temp. But yes, on the trend line, it's -.4 to +.2 I tend to not want to extrapolate. Even though I expect that .3 fall from 2005 to 2006 will rocket up again at some point as it has done over and over since 1880, it could just as well go down under the 0 line as it's done many times also. And although the trend over time has been +.05 a decade, the swings in each decade tend to be less than .5 I don't know what that type of variation means, and I don't think anyone has a firm grasp on the import.

As far as 30 years, given the wide swings over the last 126, the National Research Council themselves said in 2001 (+.33, +.05 compared to 2006) (which is interesting -- in 5 years, we've already hit the .05 per decade trend -- but downward). In any case, they "...concluded that the observed difference between surface and tropospheric temperature trends during the past 20 years is probably real, as well as its cautionary statement to the effect that temperature trends based on such short periods of record, with arbitrary start and end points, are not necessarily indicative of the long-term behavior of the climate system."

But of course, yes, over the globe, the general trend is up. If, as I said, that's accurate and out of the margin of error of the measurements.

I do understand that there are those that think the science is clear enough to act upon it now, that the change is too much, that we're causing most of it, that we can do something meaningful about it, and that the effects will be dire. I just hope others understand that some of us disagree with one or more of those. It doesn't mean we say nothing's happening nor that we say nothing should be done.

It's moved out of science and into policy.

By Robert S. (not verified) on 20 Apr 2007 #permalink

guthrie: It's interesting you point out the bit about the line-by-line is that's my point - this is very political. And I agree, the science does speak for itself. Two very different things. (And I'm still waiting for somebody to tell me the margin of error.)

Now it's up to those that have created the science to prove what it specifically means to consumers, governments, businesses, and educational institutions. The people that will actually spend the money, spend the time, and spend the energy to implement these things need to be convinced of them. Somebody has to convince them.

Showing them charts of a trend of 5/1000th of a degree centigrade a year average rise in the mean is not going to. Why do you think I keep saying it was -.2 in 1880 and +.3 in 2006? You're not going to convince the to spend 50 billion dollars a year with a variation of .5C over the chart period. Nor with a trend that's produced a rise of .7

(Government official: "Oh, really, you're telling me .7 rise in 100 years is more to worry about than a .7 drop in 11 or a .5 rise in one year? Who let you in, again?")

They don't care if it's .2 or .5 or .7 or 1 up. (My mistake earlier, the trend is -.4 to +.3(not .2)) They'd say things like "The place I live in is usually about -10 to -5 C in the winter and +34 to +38 C in the summer. I can't get concerned about 1C or even 5C over the course of 100 years -- I vary up to 48 C in one year. Some days the temperature changes 10 C that one day. Good day, and thank you for the information. We'll take it under advisement." And when you leave, you're lucky if they file it in something other than the circular file.

"Nice chart. Hmmm. That does look bad. But not bad enough to do anything about."

"Why is that only on a scale of -1 to +1? That doesn't seem like anything."

"What about this drop here at the end of the chart? It'll keep doing that, big deal."

"What's the margin of error on the measurements?"

Those are the questions that will have to be answered and objections satisfied. On a policy level. To the people that run things. Not to me, not to bloggers, not to the newspapers. To the folks with the money.

And it's not going to be done with "Future changes in climate are expected to include additional warming, changes in precipitation patterns and amounts, sea-level rise, and changes in the frequency and intensity of some extreme events."

The head of some large organization is going to think "So?" At the least, somebody's going to ask one or more of these:

How long is this future?
What percentages are the expectations?
How much additional warming?
How many changes and of what types in precip.?
How much of a rise and with what impact?
What changes in frequence and intensity?
What exterme events?

And they're not going to read the entire (or maybe not any) of the IPCC report(s), nor are they going to give you the time to explain it to them, nor are they discuss it with you like we're doing here.

By Robert S. (not verified) on 20 Apr 2007 #permalink

Tim, I stand by my interpretation of the literature. Do you stand by your allegation of academic misconduct?

By Sinclair Davidson (not verified) on 20 Apr 2007 #permalink

Chris O'Neill: Yes, the trend starts at -.4 and (my mistake) ends at +.3
I was talking about the values (-.16 and +.28) mostly. I guess I didn't make which was which clear enough for everyone.

I don't have a predetermined conclusion, I'm saying "The data was at x in year y and a in year b". Then at various other times, I'm saying "The trend line from those two points is c to d". Sorry if I've made anyone confused by that. I should stick with one or the other, sorry. Just trying to make it replicatable and explain the start and end data points.

As I explained my last remark, probably nobody you're going to talk to is going to care if it's .5 actual temps from start to end or a .7 trend in the period. (I would bet that's in the margin of error for the measurements anyway (sorry for sounding like a broken record on MoE, but it's pertinent to what we're looking at).)

In any case, at least I gave the link, the numbers and the methods.

By Robert S. (not verified) on 20 Apr 2007 #permalink

Looking at some of the comments, and thinking about providing information to replicate things, let's see what happens when you don't.

Questions about a paragraph about a "study" from an originally published work a couple years ago:

What section(s) of the ISI database did you search?

How does the "drafting of such reports and statements" correlate with published papers?

Did you mean papers published that had abstracts, or did you really mean what you said, abstracts that were published?

How do those abstracts/articles/papers prove "legitimate dissenting opinions" are not being downplayed? Since it seems to be work from the same people who are making the statements or have the same mindsets, explain how showing us that material proves no downplaying.

What was your criteria for determining if that particular abstract was about climate change or not?

'An analysis' was made, then 'our analysis'; who did the analysis?

Why was the term "climate change" picked, your final paragraph references "anthropogenic climate change"; why didn't you search on that?

The paragraph as originally published:

"The drafting of such reports and statements... ...might downplay legitimate dissenting opinions. That hypothesis was tested by analyzing 928 abstracts, published in refereed scientific journals between 1993 and 2003, and listed in the ISI database with the keywords "climate change" (9)."

Footnote:
9. The first year for which the database consistently published abstracts was 1993. Some abstracts were deleted from our analysis because, although the authors had put "climate change" in their key words, the paper was not about climate change.

I removed "...involves many opportunities for comment, criticism, and revision, and it is not likely that they would diverge greatly from the opinions of the societies' members. Nevertheless,..." because it's inane (or is that a non-sequiter or misleading?) but mainly because it makes it difficult to understand what point's really trying to be made. The entire thing op/ed is here of course: http://www.sciencemag.org/cgi/content/full/306/5702/1686

By Robert S. (not verified) on 20 Apr 2007 #permalink

I rarely find myself agreeing with Jeff Harvey, but I found his post of 20 April 9:25am one that I can agree with much of.

My question to you Jeff is why don't we focus our resources on those issues where we can actually make a difference in a reasonable time frame?

We have all benefited greatly by the work of conservationists in raising consciousness about environmental issues, and the actions taken in response. Much progress has been made.

Major cities like London, Sydney (two I know well) now have much cleaner air than was the case 40 years ago, and we also have much cleaner water in Sydney Harbour than was the case then. There have been many other gains. Mining practices for example, in most countries now, are environmentally responsible with mining companies focussing on restoration once their mining activities have been completed.

There is clearly much more to be done, but there is a lot of recognition of the issues among the wider population.

My concern is that focussing so much effort/attention/publicity on dubious AGW issues detracts from efforts that could bring major gains quite quickly. For example, as the Copenhagen Consensus exercises have shown, improve drinking water quality for the world population, deal with communicable diseases/HIV/Aids, foster economic development to raise the standards of living for those living in the developing world (people become more environmentally responsible once their basic needs are met), and focus on damaging exercises like uncontrolled residential development in sensitive areas, old forest logging, questionable farming practices etc.

Bruce: I agree. There's a lot of things we can do now and that give us more of a benefit now and that cost less.

Chris O'Neill: Correction. If you're talking about what I think you are, the -.2 to +.2 you mentioned first is the trendline (not start and end) for the 0-20/44-53 area of Europe (landmass) from 1880-2005 (Although when I look at it again, it's more like +/- 2.5) The start and stop for the entire globe is more like -.15 to +.3

By Robert S. (not verified) on 20 Apr 2007 #permalink

Once again, Sinclair - and no, you haven't answered this - what the hell does this piece of statistical jibberish mean:"If the IPCC have a large data, as they claim, 90% may not be statistically significant."

90% is not a magical number proving statistical significance - it is, in Sinclair's claim, a confidence interval. It is what it is, it is a value range that results from a calculation. Not 90%, nor 95%, nor 99%, nor 99.9%, magically confer 'statistical significance.' The value that one will consider significant is CHOSEN, with attention paid to the risk of Type I and II errors. To say that "90% may not be statistically significant" is either a meaningless truism, or betrays deeply muddled thinking about statistics. I suspect Sinclair means 'the true value may be lower than 90%" but if he puts it that way, he has to admit he has no evidence for that claim.

And even more, This argumetn from Sinclair IS IRRELEVANT TO THE 90% VALUE HE IS DISPUTING. The 90% value Sinclair is attempting to say 'may not be significant" (I shudder to repeat that jibberish) IS NOT A CONFIDENCE INTERVAL. It is a probability estimate. IPCC are saying 'the probability is 90% that" and NOT 'We reject the null hypothesis at the 90% level." Those are deeply different statements. The nit that Sinclair is picking is relevant to confidence intervals, AND THIS 90% VALUE IS NOT A CONFIDENCE INTERVAL.

Flipping a fair coin gives a probability for [heads] of 0.5. That is not a confidence interval, it is not a statistical test, issues of statistical testing to do not apply to it. It is simply the probability.

The IPCC number Sinclair is disputing is a PROBABILITY, not a confidence interval - and yes, I'm repeating the point, hoping Sinclair the statistician will respond to it. I don't know how IPCC arrived at that number - I suspect I'll have to read the full report to find out. But I do know that a possible large-sample corner case that is applicable to CONFIDENCE INTERVALS is not relevant to this PROBABILITY value - no matter how much data IPCC has.

What ARE confidence intervals, are those bands in the attribution figure (IPCC SPM Fig 4). Sinclair has already admitted that Lindley does not apply to those confidence intervals.

In the introduction to our Review paper, Alex and I write,

... Importantly, the summary states that there is a "very high confidence that the globally averaged net effect of human activities since 1750 has been one of warming". In other words, human events since the industrial revolution began have contributed to global climate change. Most of the increase in average temperature is very likely due to human activity. Readers who struggle through the entire 21 page document - with 33 drafting authors and 18 draft contributing authors it is a difficult effort - will notice the terms "very likely", "very high confidence" and the like. But what do these terms mean? The IPCC employs very clumsy terminology and, indeed, manage to conceal precise meanings in their report.

'What does the 90% figure mean?', is our question. If they have a large data set, have they corrected for Lindley's paradox? (I suspect not), if they only have 19 observations then the whole process is a waste of time. I, however, don't think the IPCC process is a waste of time - but on the evidence to date, I am yet to be convinced that AGW is occurring. I stand by that argument.

By Sinclair Davidson (not verified) on 20 Apr 2007 #permalink

Tim, you've come a long way in this argument. You started by denying I had any evidence for my statements, and now you're contesting the meaning of my evidence. To be fair to you, I understand your difficulty; what else could you say?

By SInclair Davidson (not verified) on 20 Apr 2007 #permalink

Davidson - very bluntly, bullpucky.

On page 4 of the SPM, footnote 6 define what each of those 'likelihood' phrases means:
"In this Summary for Policymakers, the following terms have been used to indicate the assessed likelihood, using expert judgment, of an outcome or a result: virtually certain, gt99% probability of occurance, extremely likely, gt95%..."

They go on to assign a PROBABILITY to each of those phrases.

Now, one more time - are you standing by your application of potential issues with confidence intervals (for which you have no evidence BTW, other than a vague "they claim lots of evidence"), to apply those to assignment of probabilities? If so, on what basis?

Yes. I stand by my comments. How hard can this be?

Further in the paper we write,

Hidden away in the footnotes, the IPCC report translates these terms. "Extremely unlikely" means less than 5 percent probability and "very high confidence" means "at least a 9 out of ten chance of being correct", or 90 percent probability. These terms indicate "the assessed likelihood, using expert judgement, of an outcome or a result". The layman reading this might think that there is a 90 percent probability that human activity is causing global warming - indeed, the Australian newspapers reported the IPCC is that manner. Yet, it is unclear what that 90 percent represents.

By Sinclair Davidson (not verified) on 20 Apr 2007 #permalink

Davidson, you are blatantly ignoring multiple questions. I can only assume you have no intention of responding to them. One wonders why?

The 90% number is a PROBABILITY, "using expert judgment" (a direct quote) of the outcome. So one more time - are you standing by your use of Lindleys paradox (which if it applies at all, applies to confidence intervals) to a probability assessment? Does Lindley's paradox apply to probabilities? Better yet, do yo stand by your apparent statement that a cited probability is a confidence interval?

Also, the IPCC process is based on evaluation of literally thousands of papers. Does Lindley's paradox apply to meta-analyses of multiple studies, none or few of which individually have data sets large enough for Lindley to be an issue?

Sinclair, you don't have any evidence. Which is why you fabricated it by doctoring a quote from Judge. You haven't offered any defence at all against this charge. I'll let the jury decide whether you are guilty or not.

Tim, I'm sorry, but your last comment is just wrong. You asked for evidence of a book, I provided it. You then claimed to be unable to find any evidence in the book, I provided that too. Now you claim I engaged in academic misconduct.

If you believe I am wrong, and that is your right, then you'll also believe these articles are wrong too:

Robert Connolly, 1989, An examination of the robustness of the weekend effect, Journal of Financial and Quantitative Analysis, 24(2), 133 - 169.
D. J. JOHNSTONE, 1990, Sample Size and the Strength of Evidence: A Bayesian Interpretation of Binomial Tests of the Information Content of Qualified Audit Reports Abacus 26 (1), 17-35.
D. J. JOHNSTONE. 1994, A Statistical Paradox in Auditing Abacus 30 (1), 44-49.
D. J. JOHNSTONE and D.V. Lindley, 1995, Bayesian inference given data 'significant at α': Tests of point hypotheses, Theory and Decisions, 38(1), 51 - 60.

Writing responses to all these articles should keep you busy for the next while. (It might be harder than you think, though, Johnston 1990 had both Lindley and Judge as discussants).

By Sinclair Davidson (not verified) on 20 Apr 2007 #permalink

Lee, As best I can work out, your questions are:
1. Do I stand by my critique of the IPCC? Yes.

2. Does Lindley's paradox apply in the case of the IPCC SPM? Maybe. It depends on what they did and how much data they have. If they have a small sample then no. If they have a large sample then maybe.

3. Does Lindley's paradox apply to meta-analysis? The IPCC do not appear to have conducted a formal meta-analysis, but I would expect in a study of thousands of papers that sample issues may be important.

MY QUESTIONS: What does 'expert judgement' mean? Did they survey the experts? Where is the analysis? Did they do a meta-analysis? Where is the analysis? What did they do?

By Sinclair Davidson (not verified) on 20 Apr 2007 #permalink

Robert S: "If you're talking about what I think you are, the -.2 to +.2 you mentioned first is the trendline (not start and end) for the 0-20/44-53 area of Europe (landmass) from 1880-2005"

OK, so when you say:

"The entire globe starts at .-2 (1880) and ends at +.2 (2006)", you're still wrong. The error was in the subject rather than the oject. At least we know we can't rely on what you say.

Robert S: "The start and stop for the entire globe is more like -.15 to +.3"

I have no idea how Robert S gets those figures. Starting on http://www.ncdc.noaa.gov/gcag/gcag.html , leave the button on "GHCN - ERSST" and click "submit", leave Lon West at -180, Lat North at 90, Lon East at 180, Lat South at -90, leave Begin Month on January, Set End Month on December, and click "Make Graph" gives a trend graph starting at -0.4 (1880) and finishing at 0.2 (2006).

Until Robert provides some explanation for this discrepancy, I won't be believing anything he says.

By Chris O'Neill (not verified) on 20 Apr 2007 #permalink

Robert S.: I just wonder what grounds you don't find sufficient evidence to support AGW. You're either claiming "all of the climatologists are wrong on these grounds" or "I just have a gut feeling". If it's the latter, please just come out and say it. In the case of the former..

If you think the models (all what.. 70 something of them?) are wrong, then what parameters need to be changed to fix them? Is snow albedo treated improperly? Are certain feedback processes (clouds, for instance) given too much or too little weight? Are scientists forgetting a forcing agent (atmospheric aerosols ARE accounted for, regardless of an earlier comment)? And of course, what evidence do you have for any of this?

Is it more fundamental? Do you not believe that atmospheric CO2 concentrations are rising due to humans? Or that CO2 absorbs strongly in the infrared? Once again - what evidence?

You spend a lot of time discussing surface air temperature anomaly measurements, but there are a plethora of other proxies to suggest that the Earth is indeed warming. Sea surface temperatures and associated sea level rise, glacier and artic ice cover retreat, circulation changes, etc.

Evidence aside, your point about framing (if I dare to use that word on a blog right now) the science for politicians is an excellent one. I don't feel like elaborating at this time, other than to say I see the difficult in conveying the danger in a 1K warming to the public.

By LogicallySpeaking (not verified) on 20 Apr 2007 #permalink

I'm afraid that to me (Layman in stats), it looks like Tim et al have shown that Sinclair has actually confused two differetn ways of playing about with numbers, and then proceeded to attack the IPCC with them, even though his numbers have no relation to what is measurably going on in real life.

Umm, robert, you said:
"guthrie: It's interesting you point out the bit about the line-by-line is that's my point - this is very political. And I agree, the science does speak for itself. Two very different things. (And I'm still waiting for somebody to tell me the margin of error.)"

As far as I am concerned the margin of error between politics and science can be infinite, but we don't know how to measure it yet. So, given this trifling problem, I still think your maundering on. Loo, the prediction sthat have held steady so far are for somethin glike a 3 degree average rise with a doubling oc CO2 levels, whcih will be achieved this century no problem at all if we don't do anything. We donot have a full undertanding of the consequences, but every one that is studied turns out to be bad.
I don't know where your getting this 0.7 in a century warming idea from, suffice it to say whatever numbers you pull out your backside are irrelevant. Answer the science, or look like a fool.

Sinclair, I doubt that you understand the journal articles you cited, but in any case none of them are an "elementary textbook of statistics". You claimed:

>As an elementary textbook of statistics reminds its readers, with large data sets, confidence intervals have to be increased, so a 90 per cent confidence level would not then be valid -- the hypothesis is falsified.

The only support you've offered for this is a fabricated quote. But you're standing by it.

No Tim. I have not manufactured a quote. That is a very serious allegation of misconduct that you keep making. I have added these journals as additional evidence of the paradox in use. You are familar with the concept of evidence and journals, aren't you?

By Sinclair Davidson (not verified) on 21 Apr 2007 #permalink

Let us start small. The perfectly stupid way of fitting a noisy data is to draw a straight line between two endpoints. For one thing this ignores all the other data you have taken. Robert S. appears to have found this as many denialists before him. One can, of course dress this fallacy up as the many claims we have heard that there has been no warming since 1998. I am greatly surprised that our new friend Sinclair has not commented thereon. The noisier the data, the worse the error. Usually the instructor gives an F-- for this and proceeds to make an example of the perpetrator.

Sinclair the Ponderer: "Fabrication in what sense?"

William Jefferson Clinton: "It depends on what the meaning of the word "IS" is."

"serious allegation"

Sinclair, the only thing you have proven is that you do not have easy access to science materials. Did you really think you could get away talking statistics without knowing what 90% percent means? You are a dirty liar Sinclair.

OK. So it seems Davidson does NOT know the difference between a probability and a confidence interval. And he's an economist?

Scholar, Lee - you are, of course, entitled to your opinions and I respect your right to be wrong.

By Sinclair Davidson (not verified) on 21 Apr 2007 #permalink

Scholar, Lee - you are, of course, entitled to your opinions and I respect your right to be wrong.

By Sinclair Davidson (not verified) on 21 Apr 2007 #permalink

Well, in fairness, you seem completely unaware of the difference between probability and confidence interval - at least you do not demonstrate it here. Furthermore, you fail to respond to his points which (in my opinion) are very clearly laid out.

To recap what he's saying (and he can correct me if I'm wrong):
- the 90% figure in the IPCC is a probability
- Lindley's paradox which you keep talking about only applies to confidence intervals
- probabilities and confidence intervals are completely different things
- probabilities never convey a statistical significance (that phrase is meaningless)

Now, maybe Lee is wrong on one or more of these points. If he is, you should address this and explain which assertion of his is wrong. Your continued failure to do so simply looks like you don't grasp the difference between probabilities and confidence intervals.

On a separate note, you said you were unable to contact the IPCC directly because you don't have ethics approval (although I'm not entirely sure what that means - it's unethical to ask someone a question?). Anyway, if you honestly want your question answered (how is the 90% determined?), the best, and often the only, "person" to ask is the source itself.

By LogicallySpeaking (not verified) on 21 Apr 2007 #permalink

I have never - ever - heard of a requirement, at a university or any other organization, that the organization ethics committee sign off on contacting another scientist or organization and asking about their work.

In the article we wrote that we thought the IPCC were expressing an opinion. I need ethics approval to ask people about their opinions. If I want a reference or a copy of the paper, I can contact them, but if I ask how did you form the opinion that you formed, I would need to have some ethics approval. (In my day job, I would be the person who asked researchers to explain why they didn't seek ethics approval, so I do have some practical experience here.)

Lindley's paradox applies to hypothesis testing (in cases where the sample size is large). When I've used it (or seen it being used) a formula is applied to modify the critical t value (that translates into a p-value). The 90% confidence intervals mentioned above relate to the IPCC forcasts from their reported simulations - this is not hypothesis testing. The 90% I'm talking about comes from here:

The understanding of anthropogenic warming and cooling influences on climate has improved since
the Third Assessment Report (TAR), leading to very high confidence7 that the globally averaged net
effect of human activities since 1750 has been one of warming, with a radiative forcing of +1.6 [+0.6 to
+2.4] W m-2. (see Figure SPM-2).

That's on page 5, Tim. For the record I'm doctoring this quote by not quoting the 4 pages before, or the the rest of page 5, or the remaining 12 or so pages.

The confidence intervals that are causing the excitement are on page 11. These are separate issues.

By Sinclair Davidson (not verified) on 21 Apr 2007 #permalink

Davidson, you failed to quote footnote 7, also on page 5, which clearly shows that you are wrong.

"7 In this Summary for Policymakers the following levels of confidence have been used to express expert judgment on the correctness of the underlying science; very high confidence at least a 9 out of 10 chance of being correct..."

Please let me point out the words 'used to express expert judgment" in that footnote. I'll leave as an exercise for the reader to deduce why this renders Davidson's point meaningless, if not absurd.

I'll also point out that Davidson's explanation of the ethics requirement is similarly absurd. That strict a definition would render any conversation between scientists that touches on anything outside strict confirmation of data or analytic methods, to be subject to prior ethics committee approval. By extension, nearly every conversation I have ever had or heard of at any scientific conference ever held, would be subject to prior ethics committee approval.

It looks to me like Davidson is taking ethics appropriate to human subjects of studies, and pretending they apply to conversations between researchers or research organizations. That is simply absurd.

That's rich, I need ethics approval to ask a question at a meeting? GMAFB. Folks, Sinclair and Co. have been leading you around by the nose. The IPCC SPM (and the WGI reports) are expert evaluations. Ensemble of model runs shown in the original post give the range of results between 5 and 95% (equivalent to a confidence limit) and can be directly compared to each other and a confidence limit evaluated.

On the other hand, there are many different kinds of observations and models. They cannot be directly compared with each other since they deal with different things, but they are consistent in pointing to how we are changing our atmosphere and our climate. Here, expert evaluation of the strength of all of the evidence must be used. That is what the SPM means when it says:

The understanding of anthropogenic warming and cooling influences on climate has improved since the Third Assessment Report (TAR), leading to very high confidence7 that the globally averaged net effect of human activities since 1750 has been one of warming, with a radiative forcing of +1.6 [+0.6 to +2.4] W m-2.

and

Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level

and

Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations12. This is an advance since the TAR's conclusion that "most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations". Discernible human influences now extend to other aspects of climate, including ocean warming, continental-average temperatures, temperature extremes and wind patterns

The SPM pretty clearly explains this in

Note that a number of uncertainty ranges in the Working Group I TAR corresponded to 2-sigma (95%), often using expert judgement.

and

In this Summary for Policymakers, the following terms have been used to indicate the assessed likelihood, using expert judgement, of an outcome or a result: Virtually certain > 99% probability of occurrence, Extremely likely > 95%, Very likely > 90%, Likely > 66%, More likely than not > 50%, Unlikely < 33%, Very unlikely < 10%, Extremely unlikely < 5% (see Box TS.1 for more details).

and for the Sinclair's amongst us

In this Summary for Policymakers the following levels of confidence have been used to express expert judgements on the correctness of the underlying
science: very high confidence represents at least a 9 out of 10 chance of being correct; high confidence represents about an 8 out of 10 chance of being correct (see Box TS.1)

Gonna have to wait for the WG1 report for that Box.

Davidson, you failed to quote footnote 7, also on page 5, which clearly shows that you are wrong.

err, no.

By Sinclair Davidson (not verified) on 21 Apr 2007 #permalink

So IOW, Sinclair, you already knew the content of footnote 7, and either you cant understand a simple statement that this is not a hypothesis test (and therefor Lindley is not applicable and yo are at best borderline incompetent) or you continue to present it as if it is a confidence test (and therefore you are dishonest - and pretending it is so does not make it so, so Lindley STILL is not applicable).

Which is it?

Eli,

"Folks, Sinclair and Co. have been leading you around by the nose."

There comes a point when one continues prodding simply through a curious fascination to see where the next response will spin to.

We don't know what the 90% is. What does 'expert assessment' mean? That is the whole point here. I would actually be happy if it were some survey, even a show of hands ("okay, people, are we happy to say 90%"). I expected a meta-analysis. End of the day, we have a contextless number.

I agree, this prodding is adding no value apart from (morbid) cusiousity. I'm having a good time.

By Sinclair Davidson (not verified) on 21 Apr 2007 #permalink

All this kefuffle about 90% probability v confidence levels is surely missing the real point. Which is: How can the IPCC justify a statement in the SPM saying that there is a 90% probability that most of global warming is caused by man's activities, when careful perusal of the rest of the document demonstrates a great deal of uncertainty about many elements.

How come?

Sinclair, you misquoted. Those footnotes do NOT say "expert assessment." They say "using expert judgment" and "express expert judgments." The meaning is quite clear - the represent the opinion of the experts. The overall Sumary SUMMARIZES the conclusions and opinions of the full report. Teh details will be in teh full reports.

But, on topic here, an expert judgment is not a hypothesis test. You raised specific concerns WHICH ARE NOT APPLICABLE HERE and you have not withdrawn those criticisms. I am prodding here because I'm finding it quite funny to see a economics professor continue to stand by such egregious howlers of statistical misrepresentations.

Regardless of how the 90% was arrived at, it is clear that it is NOT A HYPOTHESIS TEST. Lindley DOES NOT APPLY. Are you willing to admit that your entire defense of Lindley was misplaced, and that you misapplied your suspicion?

I am always ready to admit I may be wrong - that afterall is part and parcel of the scientific process. (Are you ready to admit you may be wrong?)If the IPCC have a large dataset Lindley may apply, if they don't then it may not. But if the IPCC don't have a large sample, then how can they be sure AGW is occurring? Why did they say they did? The details may well be in the reports, or not. We won't know until they are fully published. I suspect, however, they won't be. But I may be wrong. Time will resolve uncertainty.

By Sinclair Davidson (not verified) on 21 Apr 2007 #permalink

Yes, 'expert judgement' not 'expert assessment'. Same principle, how did these experts assess, etc.?

By Sinclair Davidson (not verified) on 21 Apr 2007 #permalink

This week in House...

Dr Davidson: Au contraire doctors, have you considered Marie-Strumpell Spondylitis? Any elementary medical textbook will tell you.

Dr Lee: But he's got asthma.

Dr Davidson: Yes but it's a problem with inflamed ligaments.

Dr Lee: It's a respiratory problem.

Dr Davidson: are you questioning my credibility?

Dr Lee: No we're saying he's got asthma.

Dr Davidson: But how can you be sure? Have you tried bending his leg?
...

Sinclair Davidson: "The IPCC claim to have a large data set,"

"large data set" meaning a large number of papers they can refer to and a large amount of data they can choose from.

"and if they do then Lindley's paradox might be a problem."

I don't think selecting information from a set of papers the way the IPCC is doing is anything like the situations that Lindley's paradox applies to. For it to be so, the IPCC would have to be extracting some variable from each of a large number of papers and determining a confidence interval from that data set. The IPCC are not doing this. Maybe their 90% figure is an "expert opinion" and doesn't come from any paper and could be criticized on that basis but that has nothing to do with Lindley's paradox.

By Chris O'Neill (not verified) on 22 Apr 2007 #permalink

An early (1996) example of how expert opinion can be used is Jim Titus' estimations of sea level rise for EPA.

It is beyond amusing, sort of ROTFLMAO, that an economist is trying to beat the IPCC over the head with this. To poke the beast, I note that the requirement of ethics approval to ask questions has now been lifted, which indicates the degree of honesty and ethics with which it and pretty much everything els the person who raised possesses.

And yes dear Trevor, when you have many different results, all pointing in the same direction, some strongly, some not so strongly, maybe even a few which are equivocal, you can have a high degree of certainty about the overall outcome

Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations12. This is an advance since the TAR's conclusion that "most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations". Discernible human influences now extend to other aspects of climate, including ocean warming, continental-average temperatures, temperature extremes and wind patterns

Anthony, the problem is that to deal with the Dr. Davidsons you have to question their credibility, because at bottom that is the issue.

Cripes, Sinclair the Joker does not even know what Lindley's paradox is. If you RTFR (shame on us) it becomes quite clear that climate data is nowhere near the conditions you need for Lindley's to hold, ie

Lindley's paradox describes a counterintuitive situation in statistics in which the Bayesian and frequentist approaches to a hypothesis testing problem give opposite results for certain choices of the prior distribution. . . .

These results can happen at the same time when the prior distribution is the sum of a sharp peak at H0 with probability p and a broad distribution with the rest of the probability 1-p. It is a result of the prior having a sharp feature at H0 and no sharp features anywhere else.

Climate data/models are noisy due to both random processes and results being determined by multiple parameters which do not track each other, not quite white noise, but more like red noise which concentrates at low frequencies. The models also have this characteristic. This means that for Bayesian statistics one uses uniform priors or broad expert priors, thus the situation leading to Lindley's paradox never arises, and since it never arises, one is left with another clear evidence of Sinclair's ethics or expertise.

Were there not lurkers it would not be worth the water to flush such trolls down the toilet.

Eli, thanks for your comment.

Clearly you believe that "Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations12." as IPCC says.

To a 90% probability level, no less. I do concede that human activity is having an influence on climate - it is measurable. It is called the Urban Heat Island effect - if you haven't already, buy a car that has a thermometer readout and watch how the temperature changes as you drive about.

I also accept that human land use activities are likely having an impact. However, I think it by no means proven that human emissions are causing warming. In fact, it is even questionable just how much warming there actually is. I have to say that I am not impressed by climate scientists that publish temperature series that they have adjusted, but who refuse to disclose their data, methods etc to be examined and replicated.

But it seems to me that variations in solar activity could be a factor, and also, I really doubt that we understand the CO2 cycle. For example, increased CO2 levels stimulate plant growth. What is the response of the global biomass to increased CO2 levels, what are the lags, how much CO2 is sequestered in the biomass?

And as to the effectiveness of models, it seems to me to be similar to the models that predict the stockmarket. And given the relative simplicity of the stockmarket compared with the climate, I wish you luck in getting models that can accurately predict future climate conditions.

I think that it is up to the IPCC to prove their assertion that it is 90% probability that human emissions of CO2 are causing warming. So far as I can see they haven't done that, and the abundance of sceptical and alternative views kind of suggests that the claimed consensus is perhaps a bit shaky, except of course in the eyes of journalists who have been snowed by Al Gore et al.

You can see that I am not convinced.

Umm, Trevor, to save time it would help if you read this:

Hadley centre briefing that explains why it is not the urban heat island effect

As for solar effects, the radiation levels from the sun have not changed that much over the past 30 years, certainly not enough to explain the warming we have seen.
The IPCC report will give you all the information about the carbon cycle and biomass and suchlike, suffice to say we don't have time to regurgitate it on demand for people like yourself. Go and read some of the large amount of literature available online and then come back to us when there are bits that don't make sense to you.
Some more urls:

www.realclimate.org
http://www.aip.org/history/climate/

Realclimate is a website run by real climatologists who are trying to communicate their work to the public. Thesecond url is an entire book available online, called "the discovery of global warming", covering more than a century of history of our knowledge of the climate.

Trevor

Re: "I have to say that I am not impressed by climate scientists that publish temperature series that they have adjusted, but who refuse to disclose their data, methods etc to be examined and replicated."

These data are entirely public domain. If you want the data, you can buy the data from all of the national weather services that are part of the WMO. You will also find an extensive literature describing the methods etc.

Then you can run your own independent analysis. Please update the world after you have completed your work.

"And as to the effectiveness of models, it seems to me to be similar to the models that predict the stockmarket. And given the relative simplicity of the stockmarket compared with the climate, I wish you luck in getting models that can accurately predict future climate conditions"

Nonetheless, millions of people not only stick their spare money into the stock market on the basic premise that, while we can't predict what it'll be tomorrow, we have a pretty good idea how much it'll go up in a decade; but win on that bet. Oddly enough, the ones who are the biggest bettors on that game being the ones who explain to us the impossibility of doing similarly well with climate.

Trevor if one reads exactly what was stated the range the IPCC experts chose was GREATER than 90%, not to a 90% probability. Your constant mis-stating this subtle difference is indicative. Were you at all introspective and not dogmatic, you might be experiencing a bit of self doubt.

And yes, we have heard about the Urban Heat Island effect, as has anyone who has seriously considered the issue of mankind's effect on the climate. We also understand that what is measured are anomalies at each station, and that the UHI effect has been quantified by comparing anomalies at urban and rural stations. Do you know what an anomaly is? Someone gave you stuff to read.

Do you know that climate is governed by physical laws and physical laws are more dependable and rational than people.
RTFR

Chris:

How did I get the figures? By reading the numbers in the table after pulling up the data.

What was the temperature in 1880? The 1880 data point is -.16

What was the temperature in 2006? The 2006 data point is +.28

Since we're talking about a difference between the start and end temperatures of .44 I just went ahead and rounded both up, -.2 to +.3 to get a difference in temperature of +.5

The trendline for the period is from about -.41 to +.25 and that's a different subject. The trend off average. Rounded it's about +.7 The low is -.73 in 1893 and the high is +.6 in 2002. I'm not sure I can get any clearer.

I'm still saying the same thing; nobody involved in spending the money cares if it's a +.7 trend or a +.5 difference.

If the temperature where you live goes from -5 to +34 in a year: .44 or .66 or .5 or .7 or 1 or whatever.

As far as the other numbers, if you chart 0 W 53 N 20 E 44 S, which pretty much is the landmass of central Europe as far as I can tell, there is a trend of -.25 to +.25 (It's closer to +/-.25 than +/-.2, which is what I originally said. But that's Europe I'm talking about, not the globe.)

That's a low temperature of -1.99 in 1880 to -.57 in 2006 The lowest off average is -4.1 in 1963. The highest off average is +3.1 in 1975

Time series: Temperature January , 1880 - 2006
GHCN-ERSST Data Set
Selected Region: Longitude: 0.0 to 20.0 Latitude: 53.0 to 44.0

Trend: 0.07°C/decade Significance: 98.5%
Point at the lineplot to see temperature anomaly values.

By Robert S. (not verified) on 23 Apr 2007 #permalink

Robert, your doing a good job of demonstrating why it is hard to explain this to ordinary members of the public.

LogicallySpeaking: I'm not saying the climatologists are wrong, nor am I saying I just have a gut feeling. I'm saying that to me, based upon the evidence, my opinion is the case appears to be overstated and rather alarmist. And there are others who say it also, and I happen to agree with the ones that say it.

I agree WE are creating a lot of CO2. That is the one thing that's certain.

I agree the temperature's gone up. If I assume that we can accurately measure within +/-.1 or whatever, and that the measurements are accurate and meaningful, then it is warming. I'd say that's a fair assumption to make.
(Although not something that's for sure, right? Uncertainties. Most. Likely. Probably. It's all over the place. A lot of "We think so, based upon what we know".) But they're probably right about it. Probably.

I agree the models show there are possible or probable negative effects, and if we assume that with so many, some will be accurate, and if we also take it for granted the results will be in the middle of the range of possible results, if it happens, that's a bad thing. But it's not a given.

I agree that there is probably a correlation between the CO2 levels and the warming; although it seems to me that given the concentrations, there should either be more warming, or that the rises and drops should be less variable and pronounced than I see them. No, I can't prove anything. Who can?

As far as the forcing of aerosols, I basically asked the rhetorical question "How much are they masking what's really going on with the temperatures vis-à-vis CO2 in either a positive or negative direction?" I didn't say they weren't counted. I'm just wondering about their import (and how they affect the rest of the equation).

I know the ranges in um that CO2 absorbs, not denying it, low end of the thermal infrared mostly.

One question I have, which I do not consider unreasonable (and certainly others have asked), based upon what I consider to be a reasoned examination of all the factors involved in this huge complex system with many unknown or poorly understood mechanisms, that may be modeled incorrectly or not, is given the more reasonable estimates of the half-life of CO2, is it possible that the planet wants the amount of CO2 to be in the 400 range right now at this time? Or asking, does the warming trend continue as it has, or is it just getting to be where it should be? How about the possibility more plants and more temperate regions are a good thing? Or that if we weren't warming things, we'd be going into some other normal cyclical event that would harm us?

Are these unreasonable things to wonder about? I can certainly see how someone could come to the determination that it's all bad, that the danger is present and immediate, and that action must be taken regardless of the costs. It seems at times that others are incapable of understanding others could come to a different conclusion. And it's not just me, wondering, there are climate and climate-related bodies and scientists asking and wondering themselves. Not a lot, certainly, but they are there. Isn't that what science is about, asking questions and searching for answers? I don't know that Lindzen's correct or not correct about clouds etc, or variously that Bray, Jaworowski, Singer, Hansen, Pearce, Stern, Gray, Romm, de Freitas, Pulwarty, Lomborg, Mann, Kolbert, Pilkey, Svensmark, Ball, Abdusamatov, Pielke, Michaels, Rowland, Horner, Akasofu, Christy, Carter, Balling, et al are correct or not about what they think or ask. I don't know if the people here, at Real Climate, or which of the folks editing the global warming sections of Wikipedia are correct or not. There is not universal agreement, although it's clear where the majority is on their thinking.

To answer your question on modeling, I don't know which feedback processes may or may not be given too little or to much weight. I don't think anyone knows, there are just assumptions made based upon the information we have that may or may not be correct. I don't put a lot of confidence in models, since many are so often proved (eventually) to be horribly wrong.

Is there really any non-speculative or non-arguable way to predict the future based upon the past in any field? People have been trying to do that with food supplies vs. population, the stock market, and any other number of methods that sometimes look really really good -- and don't work at all. This may be the case, is that unreasonable to think, or even unreasable to ask?

These are not my words:

-----------------------
"...the observed difference between surface and tropospheric temperature trends during the past 20 years is probably real, as well as its cautionary statement to the effect that temperature trends based on such short periods of record, with arbitrary start and end points, are not necessarily indicative of the long-term behavior of the climate system."

"From the body of evidence since IPCC (1996), we conclude that there has been a discernible human influence on global climate. Studies are beginning to separate the contributions to observed climate change attributable to individual external influences, both anthropogenic and natural. This work suggests that anthropogenic greenhouse gases are a substantial contributor to the observed warming, especially over the past 30 years. However, the accuracy of these estimates continues to be limited by uncertainties in estimates of internal variability, natural and anthropogenic forcing, and the climate response to external forcing."

"The committee finds that the full IPCC Working Group I (WGI) report is an admirable summary of research activities in climate science, and the full report is adequately summarized in the Technical Summary. The full WGI report and its Technical Summary are not specifically directed at policy. The Summary for Policymakers reflects less emphasis on communicating the basis for uncertainty and a stronger emphasis on areas of major concern associated with human-induced climate change. This change in emphasis appears to be the result of a summary process in which scientists work with policy makers on the document. Written responses from U.S. coordinating and lead scientific authors to the committee indicate, however, that (a) no changes were made without the consent of the convening lead authors (this group represents a fraction of the lead and contributing authors) and (b) most changes that did occur lacked significant impact."
------------

In any case, I hope I made my point on this. I am not convinced that it's going to continue to warm, or that if it does, it will accelerate. Even if it did, I'm also not convinced 1 or 2 or 3 degrees off average is that catastrophic. And even if it is, we may run out of oil, radicals might take over the world and put us back into barbarism, a nuclear war, etc, might happen first. Or "they" may be right about 2012. Or a meteor might hit us.

I am fairly confident that regardless of what the truth is or might be, the human spirit, ingenuity and technology will adapt along with us as we go forward, and it will all be okay. Obviously, many don't agree with me. That's fine, we all have our opinions on things that others disagree with.

Sincerely,

Remaining Unconvinced

By Robert S. (not verified) on 23 Apr 2007 #permalink

guthrie:

I meant the margin of error in the yearly temperature measurements.

The .7 is not in a century, it's a century and a quarter. 1880-2006 trendline (fairly close to the .5 start and end temperatures) mean global average. I pulled them from the NOAA/NCDC figures that I've linked to a number of times.

I agree with those scientists and researchers that think a) CO2 will not double and/or b) if CO2 were to double the temperature rise will not be anything like that order of magnitude and/or c) we don't have models that are accurate enough to predict the entire system, and/or d) whatever warming we're having is not bad, e) tc etc etc

You don't. I'm just giving my opinion on it. What's the problem? Can't I say "here's what I think" and why and not have everyone act like I just burned down an orphanage? Why is it so difficult for you alarmists to understand there's those of us that don't think .7 is a big deal regardless?

I may be doing a good job at showing how hard it is to explain to the public. I wish I was doing a good job at explaining that nobody really cares, so it doesn't need to be explained.

Everyone's so busy trying to poke holes in my reasoning and highlight any mistakes to understand that some people who have looked at the data, understand the science and even agree a number of the issues (even if it's just on a "probably" basis) don't think it's important; how is the typical person going to care about it?

By Robert S. (not verified) on 23 Apr 2007 #permalink

Eli: When did I deny it was warming? Not being convinced isn't denial. Is it denial to not agree with you that the warming is important or wonder if it's going to continue, or know that it's not a 100% certainty that we have the data correct? I'd agree with the 90% figure, which probably means it is correct -- but I'm not so egotistical to proclaim it's a certainty, because it's not.

I never said there's been no warming since 1998 or anything near it, and I've never said it's NOT warming. In fact, I have made it quite clear it probably is, that I think it probably is and I have provided the data. Then I commented upon it, not as clearly as I could have, certainly. I thought this was for a discussion of views and reasoning to learn, clarify and understand.

That's unfair. I didn't just draw a line between two points; I gave the .5 difference between the two ends as well as the .7 on the trendline.

What I would ask the professor is "Are you seriously telling me that providing you with my data, and explaining the information on it by stating the start and end temperatures, the high and low temperatures in the data, and the trendline rise two different ways is some kind of trickery?" Or "Are you kidding me? .5 vs .7? Are you telling me that .2C difference over 126 years is some kind of statistically significant number when talking about a global mean surface/air temp graph that isn't even a certainty?" Then I'd withdraw from the class, since I doubt I'd be learning anything from somebody that gave me an F for giving three pieces of information from a chart that they are looking at.

If your agenda is to implement your proposed solutions to what you think is a problem that demands immediate attention, you need to spend more time coming up with better arguments for Ms. Average and Mr. Ordinary and have discussions not attacks. Nit picking details is a great way to pound the table, but it's not impressing me. And your target audience is not going to give you 10 seconds to try and humiliate and belittle them, they'll tune you out, nod their head like they agree, and go along not caring about what you said. Because they don't care.

Noisy data is right; You are drowning out the fact I gave the .7 trend as well by ignoring it and using logical fallacies and debate tactics to hide it.

In the future, I'd appreciate you not attacking me personally with debate tactics to obfuscate the issues, or by calling me a denialist, a perpatrator of a fallacy, stupid, needing to have things explained to me starting small, and deserving of an F.

By Robert S. (not verified) on 23 Apr 2007 #permalink

Because, Robert, merely giving your opinion is not science. My opinion could be that you are living on Mars. As a statement of opinion, thats all very well, but in relation to the facts that Mars has not been colonised by humans (leaving aside the conspiracy theories), the lack of internet access from Mars, etc, it is an opinion that is very unlikely to be correct.

And so we come to the warming. The point is that your taking the last century and a quarter is illegitimate because of the fact that at that stage our CO2 emissions were not noticeably affecting the climate, in fact were completely negligible.
What matters in this case is the last 50 years and our increasing CO2 output, and how we have started forcing the climate over that period. Then the picture changes from your rather blase 0.7 in a century and a quarter.

As for the Earth wanting more or less CO2, thats a fairly nonsensical statement. The EArth doesnt want anything. What we have observed in the historical record (in the current interglacial), is that CO2 levels have oscillated around a level far below what we have made now. This suggests that actually when things are happening normally, without great human influence, given the current placing of landmasses and mix of plant and animal, the normal CO2 level is indeed much lower than just now.

As for increased plants due to CO2, more recent field trials with CO2 have shown that in real life outside labs the effect is very small. Moreover, whilst some areass such as the Arctic may grow more plants, the spread of deserts in drier areas of the planet may lead to a decrease in biomass overall.

"I may be doing a good job at showing how hard it is to explain to the public. I wish I was doing a good job at explaining that nobody really cares, so it doesn't need to be explained."

Actually polls show acceptance of the AGW theory and support for immediate reaction running at 80% or more in virtually every country in the world.

Perhaps it's you and your fellow bitter-enders who should be asking themselves why they lost the debate so comprehensively.

By Ian Gould (not verified) on 24 Apr 2007 #permalink

z

Actually the climate is relatively simple relative to the stockmarket.

I worked as a professional economist, and have a postgraduate degree in an related discipline.

Climate obeys *physical laws* which are well modelled in the lab and on smaller scale. So we know a lot about what happens to a body of gas if we increase the CO2 and water vapour concentration (answer: it blocks reradiated infrared light).

Contrast that to the stock market. We don't know if an increase in the money supply increases stock prices, or lowers them: a lot depends on how market sentiment will react. Similarly we don't know if inflation is good for stock prices, or bad. Ditto unemployment. It is often the case that a company announces stronger profits, and the share price *falls*. Anyone who claims they can predict stock markets (let alone exchange rates) is spouting bunk.

Add to the confusion: money supply is almost unmeasurable (the Fed has actually quit reporting many monetary aggregates). Inflation varies on how you calculate it (how do we price a Dell PC with 3.0ghz dual pentium and 2GB of RAM, vs. the cost of that same Dell in 1979?). So does unemployment (2 rival methodologies give Sweden unemployment of 5%, and 15%).

It was guite a revelation to look at scientific models of climate, and realise there actually are modelling disciplines where the necessary simplifications make sense, are theoretically defensible, conform to well understood physical laws, and the practitioners know and admit the weaknesses.

The main factor which we are beginning to get a handle on (Hansen's famous prediction of the effects of Pinatubo, in 1991, which came true, of a 0.5 centigrade fall in average world temperature) is aerosol forcings. In particular, SO2 emissions have been masking the impact of our releases of greenhouse gases. Once Japan, the US and Europe cracked down on SO2 emissions in the mid 70s, that effect was lost (although China has picked up the slack).

By Valuethinker (not verified) on 24 Apr 2007 #permalink

I like the 'bitter-enders' bit.

I've been using 'dead-enders' to show a similarity to the wargasmers in our country, but bitter-enders is so much more evocative. I hope you don't mind, Ian, if I steal it. We can arrange royalties via PayPal... :o)

Best,

D

guthrie

It's conceivable we will get some type of CO2 fixating algae bloom, in response to increases in world CO2 concentrations.

But the speed at which we are increasing atmospheric CO2 is almost unprecedented in geologic history. It's unlikely the natural environment will evolve that quickly. Even a 1,000 year delay, let alone a 10,000 or 100,000 year one, is going to be too late, for practical human purposes.

And in particular we are destroying the rainforests, which are a huge natural carbon sink.

A second, perhaps even more terrifying risk, is increased methane release from the permafrost, leading to 'the day the Earth melted'. We know the methane is under the permafrost, and we know that if the permafrost melts, it is released.

Interestingly, the latest studies in Siberia say that methane release is 4 times what we estimated.

By Valuethinker (not verified) on 24 Apr 2007 #permalink

It was guite a revelation to look at scientific models of climate, and realise there actually are modelling disciplines where the necessary simplifications make sense, are theoretically defensible, conform to well understood physical laws, and the practitioners know and admit the weaknesses.

I think you sum that up quite nicely. You can get a similar view coming from the sciences to look at the huge amount of variables in economics.

As for an algae blom, last I knew iron was a limiting factor in their growth, and we don't know what the effects of seeding the ocean to promote blooms will be. Those who want to try it don't seem to have done any research on its effects that I have read about. (ADmittedly I am not that widely read perhaps)

Robert S:

"What was the temperature in 1880? The 1880 data point is -.16

What was the temperature in 2006? The 2006 data point is +.28"

I still don't know how these numbers come about. My running of http://www.ncdc.noaa.gov/gcag/gcag.html gives -0.22 for 1880 and the latest number is 0.51 for 2005.

"The trendline for the period is from about -.41 to +.25 and that's a different subject."

Indeed, and a rather more significant one, to say the least.

"The trend off average. Rounded it's about +.7 The low is -.73 in 1893 and the high is +.6 in 2002."

-.73 and +.6. More numbers whose source is a mystery.

"I'm not sure I can get any clearer."

I'm glad you think you're doing everything clearly.

"If the temperature where you live goes from -5 to +34 in a year: .44 or .66 or .5 or .7 or 1 or whatever" is insignificant.

I'm probably talking to someone who is deaf here but it doesn't take anything like a -5 to +34 change in the average to have major effects on many things. For example, a 2 degree C warming causes coral bleaching of many reefs of the Great Barrier Reef. Once the ocean average temperature is 2 degrees C warmer, these reefs will bleach nearly every year. Result: they will be permanently bleached and just end up as piles of rubble. A 3 degrees C (and probably only 2 degrees) average total warming will cause nearly all of Greenland to melt or slide off in a few hundred years. A 2 degree warming is about the same average temperature increase as occurs through moving 400-500 km closer to the equator at latitudes around 30 degrees. In the places I'm familiar with, there is a substatial ecological difference in native forests separated by 400-500 km of latitude in the same climatic zone. Warming by 2 degrees will take these forests out of the zones they were adapted to in probably less than the lifetime of individual trees. The Australian ski industry will be wiped out by a 2 degree increase in average temperature. A 2 degree increase is equivalent to raising the snowline by 300 metres. The vast majority of ski runs extend no more than 300 metres above the existing (very fragile) snowline. A 2 degree increase will have much larger effects on local climates than the effect of simply raising the average temperature, it can change rainfall patterns that have a major effect on agriculture. These are some of the more obvious effects of "small" temperature increases.

And the issue is not that the effects of a 0.7 degree increase is all that we have to worry about. The issue is that the temperature WILL increase more, even in the humanly impossible event that all CO2 emissions were switched off today. The temperature will increase about 0.6 degrees more in this practically impossible event. Even with the very optimistic assumption that no further coal-burning power stations are built, existing ones do not have their design-lifetimes extended and oil and gas are consumed until they run out, the temperature will most likely increase at least another 1.3 degrees.

"the human spirit, ingenuity and technology will adapt along with us as we go forward, and it will all be okay. Obviously, many don't agree with me."

Strawman alert. No-one disagrees that humans are capable of avoiding carbon emissions if they want to. The issue is whether humans can control their greed to achieve this. Humans don't have a great track record in controlling greed.

By Chris O'Neill (not verified) on 24 Apr 2007 #permalink

To everyone: I hope nobody's thinking I'm trying to convince anyone of anything (except maybe that you need to change your tactics when talking to policy makers). I know all your minds are made up, just like mine is. You think it's important, and I think it's not. I'm just telling you why I think it's not a big deal. Do I think it's going to keep going up? To some point. And maybe it keeps going. We'll never know. I'm curious to see what it will do until I die. And regardless of the support, 40% or 99%, the simple fact is, nobody's going to do anything about it. It's not greed, it's a different risk/reward ratio than you have. Which, again, is why I say this won't go anywhere unless you learn to think from the other side.

guthrie: And that's your opinion, too.

Ian: You mean bitter-ender as the opposite to an overreacting-alarmist? What 80% of people believe doesn't make true. From a policy standpoint the results are inconclusive enough. Just because some keep saying they are conclusive doesn't make that so, either. you think you're going to convince anyone with "we think probably maybe"?

Dano: Ditto

By Robert S. (not verified) on 24 Apr 2007 #permalink

Chris: Actually, I meant the variation in 1 single year, in someplace that goes from -5 to +35 (or whatever), say a city, compared to the total change in _either_ direction since 1880; that trend of .7 is dwarved by what happens in 1 year in 1 place.

Of course the Earth doesn't "want" anything, it's not human. But things happen, and perhaps this is what's supposed to be happening.

I'm not deaf; I understand that a 2 degree change will make things happen, and you think those things are bad. (And they might be, I don't know. So the reefs all melt or the glaciers all melt, or it's 13 or 15 C on average. So? Tell me exactly what it's going to do when that happens.) But it's moot -- it's never been more than .6 above average.

You think it will go over that. I don't know what it's going to do, but I certainly have admitted that looking at the figures, it certainly seems as if it will. You do notice I'm agreeing with you that the trend looks like it will keep warming, and I don't think I've ever said it wasn't. I have said it doesn't mean the trend will continue, but can't I make some "probably maybe we think so" predictions of the future myself? Or do you have to be Michael Mann or Richard Lindzen or somebody to have permission to make guesses?

On the other hand, '42 to '72 had a certain look to it also. That's a fall of .61 (numbers not trend) within 30 years. I mean, from '78 to '06 it went up, what, from average to .3 (numbers not trend) above? With all the carbon dioxide, it went up .3 total over 28 years?

How the heck are we going to get to +2?

Yes, yes, yes, I know, the trend is the only important thing, it tells us all.

It's not a strawman argument, it's not an argument at all. My opinion is we'll take care of it. But possibly we won't. If it gets over the 1 degree above average mark, I might take it more seriously. All I see right now is noise around what what's been a 1.5 range for 126 years.

And if you chart that same variation on a CO2 graph from 280 to 380, the temperature covers up the 0 line (eg, graph the temp variation after adding 360 to it and 360 is your zero line)and that's about it.

Regardless, .5 vs .7 -- I'd hardly call .2 C "significant" from an average of about 14 C You're telling me to worry about 1.4%? of the total between .5 and .7? 1.4%? The measurements aren't nearly anywhere near that accurate. It's a thimble in a hurricane. Or is that a tempest in a teapot?

And even so, okay, a .7 trend. Uh, 5% over 126 years is something to worry about? I just don't get you guys.

Where did I get the numbers? Rather than argue the numbers, go graph it. I said I was using the GHCN-ERSST Data Set in comments 109 and 198 both, so I would think you are also using that set. Which now goes to 2006 (+.28). If you are not using that data set, that would explain your confusion.

http://www.ncdc.noaa.gov/gcag/GCAGdealtem?dat=BLEND&mon1=1&monb1=1&mone…¶m=Temperature&non=0&klu=1&proce=80&puzo=0&nzi=99&ts=6&sbeX=-180.0&sbeY=90.0&senX=180.0&senY=-90.0

Or read their chart:

2006 0.28 12
2005 0.51 3
2004 0.48 4
2003 0.56 2
2002 0.6 1
2001 0.33 10
2000 0.19 21
1999 0.38 7
1998 0.48 5
1997 0.21 18
1996 0.12 26
1995 0.39 6
1994 0.14 24
1993 0.23 17
1992 0.28 14
1991 0.28 13
1990 0.2 20
1989 0.01 42
1988 0.38 8
1987 0.09 29
1986 0.11 27
1985 0.04 38
1984 0.1 28
1983 0.29 11
1982 -0.0 46
1981 0.36 9
1980 0.14 23
1979 0.01 43
1978 -0.03 51
1977 -0.04 55
1976 -0.16 72
1975 -0.0 47
1974 -0.28 96
1973 0.17 22
1972 -0.34 106
1971 -0.02 49
1970 0.05 35
1969 -0.21 87
1968 -0.26 92
1967 -0.12 63
1966 -0.13 65
1965 -0.15 71
1964 -0.08 59
1963 -0.05 56
1962 0.0 45
1961 0.0 44
1960 -0.13 68
1959 -0.0 48
1958 0.27 15
1957 -0.19 82
1956 -0.27 94
1955 0.02 40
1954 -0.28 97
1953 0.04 39
1952 0.08 32
1951 -0.35 107
1950 -0.38 112
1949 0.05 36
1948 0.05 37
1947 -0.19 81
1946 0.08 31
1945 -0.03 52
1944 0.2 19
1943 -0.13 66
1942 0.27 16
1941 0.06 34
1940 -0.13 64
1939 -0.06 58
1938 0.02 41
1937 -0.16 76
1936 -0.2 85
1935 -0.25 90
1934 -0.29 98
1933 -0.27 95
1932 0.13 25
1931 -0.04 53
1930 -0.31 104
1929 -0.45 119
1928 -0.05 57
1927 -0.19 80
1926 0.09 30
1925 -0.35 108
1924 -0.26 91
1923 -0.25 89
1922 -0.37 110
1921 -0.08 60
1920 -0.13 67
1919 -0.3 101
1918 -0.33 105
1917 -0.46 120
1916 -0.2 84
1915 -0.18 79
1914 0.07 33
1913 -0.42 116
1912 -0.29 99
1911 -0.52 124
1910 -0.39 114
1909 -0.58 126
1908 -0.39 113
1907 -0.4 115
1906 -0.18 78
1905 -0.29 100
1904 -0.54 125
1903 -0.19 83
1902 -0.08 61
1901 -0.23 88
1900 -0.27 93
1899 -0.15 70
1898 -0.04 54
1897 -0.16 77
1896 -0.16 73
1895 -0.48 122
1894 -0.48 123
1893 -0.73 127
1892 -0.3 103
1891 -0.37 109
1890 -0.3 102
1889 -0.14 69
1888 -0.43 117
1887 -0.43 118
1886 -0.16 74
1885 -0.48 121
1884 -0.21 86
1883 -0.37 111
1882 -0.02 50
1881 -0.1 62
1880 -0.16 75

Hope that helps.

By Robert S. (not verified) on 24 Apr 2007 #permalink

Actually Robert, we only want to stop the casual reader from believing that you have a clue. True you sling the stuff hard fast and long, but you obviously don't have a clue about climate. Why don't you compare the raw data with the seasonally detrended data (you take the average for each month over 30 years and then subtract the average from the data month by month.

Of course, the trends are larger when you look at high latitudes.

Next you can talk with folks who know about how animals and plants are affected by a different change of seasons and many other such things. Hint...it is not a pretty picture.

Robert S: " To everyone: I hope nobody's thinking I'm trying to convince anyone of anything (except maybe that you need to change your tactics when talking to policy makers)."
...
"Ian: You mean bitter-ender as the opposite to an overreacting-alarmist? What 80% of people believe doesn't make true."

You miss my point Robert - which is that the side that's winning decisively in the public debate hardly needs to take debating tips from the side they're thrashing.

By Ian Gould (not verified) on 24 Apr 2007 #permalink

Robert, which particular bit is my opinion? I'm just going by science (2007). Maybe you are going by science (1980) or science (1890) or something. It is rather hard to tell. You have not come up with a single scientific argument, just a lot of opinionated handwaving.

Over at the old Quark Soup, there was a commenter there, similar to Robert but not as sharp. He'd throw out all kinds of goop as justification for his ideology too.

When we'd show how his goop was cherry-picked, out of context, old, or simply wrong, he'd feign ignorage and change the subject. Then, two weeks later, he'd bring out the same discredited, cherry-picked goop.

He'd do this so often I just started calling him lala (lalalalaaaa...I can't heeeeear you).

Once one recognizes it is all about the tactics (I see them called out just above), one can then skip over the comment, knowing the motive for the content is obfuscatory and mendacitic in nature.

Best,

D

Robert S (man of mysterious numbers): "On the other hand, '42 to '72 had a certain look to it also. That's a fall of .61 (numbers not trend) within 30 years."

According to http://www.ncdc.noaa.gov/gcag/gcag.html , 1942 global was 0.04 above base level and 1972 was -0.05 relative to base level, thus a fall of 0.09 from 1942 to 1972. How Robert S gets his numbers is a total mystery because running his link:

http://www.ncdc.noaa.gov/gcag/GCAGdealtem?dat=BLEND&mon1=1&monb1=1&mone…¬âm=Temperature&non=0&klu=1&proce=80&puzo=0&nzi=99&ts=6&sbeX=-180.0&sbeY=90.0&senX=180.0&senY=-90.0

once his error characters "¬â" are corrected to "¶" (clicking on his link gives an error report) gives a set of numbers totally different from the ones he is feeding us e.g., the 2002 figure is 0.45 while Robert S feeds us 0.6.

Considering how incompetent Robert S is with the numbers, it's no surprise that he's incompetent at understanding any other issue to do with global warming.

By Chris O'Neill (not verified) on 25 Apr 2007 #permalink

One question for everyone, why are we doing a linear trend and not a logarithmic one? (Seriously, I don't know) Oh well, probably not important.

Eli: Just because I don't agree with you on the details doesn't mean I don't have a clue about climate, but sure, not an expert. I just think the current apparent warming's danger is being overstated. (Is it so impossible for somebody to look at the same data you are and come to the conclusion it's not as bad as some make it out to be?) But yes, I could be wrong. I don't understand your agressive behavior just because I don't agree with you on the details. Maybe if everyone spent more time coming up with solutions and answering questions instead, something might get accomplished in the climate sciences arena.

Interesting graph, seen it before. Doesn't look like anything to worry about. I could be wrong. (That's a .6 trend from '70 to '06 or around the same 5% as 1880-2006)

I see a lot of this being driven by the IPCC, but it seems a mainly political body that's overstating the case to compel action, because there are many that feel as passionate about it as you do.

And in fact, I have nothing against that at all.

But they're too obvious about what they're trying in the first place, and I just don't think they're doing a very good job at compeling action, at least not right now. They seem to be getting better though.

I know what the effects could be. I think you're overreacting, but that's just my opinion. But now it's time for mitigation and adaptation strategies to be implemented according to a plan of action; sound policy decisions made according to how we can get the most done, in the least time, with the least expense. More than anything, I'm saying a poor job is being done with getting specific action taken. Too much emotion and not enough logic.

Ian: Fair point. Raising fears with propaganda to get the masses reading all the news stories to worry about things (not that it seems much action is being demanded). Now that the public debate (I thought it was a discussion, but there you go) is over, all that needs to be done is something to get policy enacted. That's the trick, isn't it? Get the policy in place. That's not debate advice, it's a question of what you plan to do next, because nothing seems to be happening.

I fully support reasoned, intelligent, worthwhile action on this, just in case it's true. Not to the degree of urgency of course. It just appears that there's too much arguing about details goes on. And competitive coversations like this one we're all having.

I have never said "The Earth is 100% for sure NOT warming." nor anything close. I've said it probably is, haven't I?

If people that agree with all this in general get this type of treatment, how will anything get anywhere (not on the debate, on the implementation) with people in government, academia and industry?

guthrie: That this is something to worry about is an opinion. What the import of the data is is an opinion. What's not an opinion is that we've never gone warmer than .6 over average. I'm sorry, but I just can't get excited about it.

Try this: Get the Law Dome and Mauna Lua data (at CDIAC), graph it from 280 to 380 from 1832 on, which is pretty much the entire graph space, 280-380. Then graph the mean temp variation from the GHCN-ERSST Data Set globally from 1880-2006 by adding 340 to each data point and have a 340 line for the CO2.

The region the temperature variation takes up, and the reaction of the temperature compared to the huge update in CO2, is puny. Yes, I know about CO2 forcing, and the lag, but why aren't we seeing more of an effect? It's still in the same 1.5 range it's always been. Science?

Also, look at the GHCN-ERSST for 2002 to 2006. Back down to +.3 Yes I know the trend line. I'm saying I am not concerned about a linear trend 5% (.7 of 14) raise over 126 years, nor with the same trend over the last 35. Sorry.

dano: I'm not cherry picking anything. We're talking global warming, I'm looking at data on global warming. Are you saying there's something wrong with the GHCN-ERSST data? Something bad with the CO2 data from the Carbon Dioxide Information Analysis Center? Am I mis-stating that we've never been more than .75 off average, ever? Should I be using another data set? Should I be graphing things from HadCRUT3 on a -.6 to .6 scale to accentuate a huge graph? You haven't showed me anything, you've spent most of your time attacking me rather than answering my points, except by giving me the same information I told you I don't agree on the importance of in the first place, over and over.

Chris: Now that you've attempted to run me around and around so I forgot you never answered my question by acting as though my saying a winter of -5 and a summer of +34 in one year was instead saying the globe's average changed that much, and by repeatedly asking me where I got -.73 and .6 and -.16 and .28 - and I've told you three times where they're from, would you care to answer my question about why .5 or .7 over 126 or 35 or whatever years is something to worry about?

By Robert S. (not verified) on 25 Apr 2007 #permalink

Chris, regarding your comments on the data:

First of all, the blog messing up the link doesn't make me incompetent. It didn't work for me either.

Second of all, I put the numbers in the message also, they're right there to look at: 1942 0.27 16 and 1972 -0.34 106. (The third number is the rank.)

Third of all, I've given the link 3 times now to the main page, all you have to do is go get them yourself since the link doesn't work and the data is unformatted in the message.

Fourth of all, here's how to do it:

1. Go to http://www.ncdc.noaa.gov/gcag/gcag.html

2. On that page, Time Series "Global" and "GHCN-ERSST" as the dataset.

3. Click "Submit"

4. Click "Create Graph" and wait. (The defaults are the lon/lat for the globe from Jan 1880 to jan 2006 on a line plot.)

5. The chart will come up, interactive with numbers on the data points and the chart with the data points below that.

Fifth of all, Your opinion on my understanding global warming or not is a meaningless non-sequiter. And you don't seem to be having much luck with the numbers either. At least I know where to go get them, and I've told you. It's certainly not my problem you can't find them and it has nothing to do with me understanding global warming.
(It's trending +.7C above over the last 35 or 126 years, it's around .3 above for 2006, CO2 concentrations has gone up around 100 ppmv since 1832, there's more methane, the oceans are warming, the poles are melting, animals are migrating, vegitation is vanishing, UHIs are creating heat, there's billions of people contributing to the environmental and ecological systems of the Earth, India and China are becoming major industrial powers, the US is performing research and mitigation methods but the Senate won't ratify Kyoto, which nobody seems to be adhering too anyway. etc etc etc. What's to understand?)

Lastly, rather than details; Why is .7 C over 35 years something I need to worry about to the point where I have to make sure something, anything and everything is done, right now, no matter how expensive it is, no matter how small the impact it has, no matter how it impacts other mechanisms in climate, global and national economies, food production, and disease, and regardless of what other scientific research and projects are going to be defunded to pay for it.

By Robert S. (not verified) on 25 Apr 2007 #permalink

Robert S

Lets try a different approach. Why is sea level rising? Why is the extent and concentration of sea ice in the Arctic declining? Why have huge amounts of timber been recently lost in British Columbia? Why is it difficult to get insurance for coastal properties on the US Gulf Coast? Why are many species experiencing changes in their range? etc etc

This tiny insignificant amount of climate change that we have already experienced is responsible. If you want to know what is to come, begin by reading the Summary for Policy Makers (Working Group II, Impacts, Adaptation and Vulnerability) from the IPCC fourth assessment reports. You can download the file at www.ipcc.ch

After reading the document you may have some questions or comments, there are many that could help you and discuss. However, the shotgun approach is not very effective. Start with one point.

JP:
Thank you, an answer at last! "Most of us are 90% or more certain those events are due to the warming trend of .7" That sounds reasonable. (Although in the case of insurance, it's probably because more people are building more expensive homes on the shores, and events like Katrina have happened)

Now, if you'll go back to my comment, 109, you'll see I basically asked one multi-part question; what is the margin of error in the measurements in the data of GHCN-ERSST, is low-high of -.2 to +.3 troublesome, is the graph better at +/-5 and was falling from 2002-2006 to +.3 (or falling/rising some other periods) any more or less troublesome then those variations.

Somebody could have just said something like:
1. We don't know the margin of error but it's probably statistically insignificant.
2. The high and low are not as important as the trend, which is .7 The .2 difference between the start and end of .5 to .7 is a large difference given the effects.
3. "Simply" a .7 trend is bad enough, and is causing tremendous issues with the environment, but enough scientists think it will continue to grow even past that to make it as proven as can be with science. The 2 degrees they think it would rise would be catastrophic, and we can't afford to wait to see if it rises 3 degrees in 50 years.
4. What's needed is rational and calculated steps to mitigate and adapt to these changes, and a rational and lucid conversations on the issues, the proposed solutions, and the costs, to assist policy makers in implementing sound policy.

I guess I should have given somebody the opportunity to eventually get around to some kind of answer like that before posting more random thoughts. My fault.

Anyway, in that case, if the prevailing opinion of those involved in guiding the consensus and involved in in producing the IPCC FAR is that the .7 trend is causing all the climate-related issues and it's only going to get worse, than all of the discussions should be about how we get the people in power to do what the IPCC is suggesting, and to get rational, reasoned conversations going on how to best go about it.

In reality, the truth of it is immaterial as far as that standpoint goes, as long as we're not introducing unforseen consequences into the equation.

What do we now do to mitigate and adapt to the warming? That's all that should be important, right? No, I don't have the answers, nor the questions. Nor is there anyone I can convince to take action. (Well, I could survey the public and find out 8 of 10 answer 'global warming is real' but won't do anything about it.

Hopefully, somebody will do something about it without doing silly things like spending a trillion dollars to freeze CO2 to make barely a blip in the concentrations or suggest silly things like killing half the humans on the planet.

Here's what's not helpful:

When people don't agree with you, attempt to belittle them, and when it doesn't work, don't answer any questions, just put your fingers in your ears and sing to yourself, pouting. The policy makers see that, and that makes them not only not want to take action, it makes them doubt the entire IPCC process, and doubt there is any real scientfic consensus.

This is not helpful either:

I don't see why .5 is a big deal.

You're an idiot, it's .7 and you're making your numbers up.

I got them here, and okay, let's go with the trend. Why is .7 a big deal?

I don't see where you got the numbers.

Here. So what's .7?

Don't you know what will happen if it rises 2? You're an idiot.

But it's never gone over .6

The trend is .7

Okay, so how do we get to 2 when it's just dropped .3 since 2002, when it was only .6?

Don't you know how many polar bears will die as they migrate out of land with a rise of 2?

I thought we were talking about a trend of .7 over x years or something.

It's going to get worse.

Probably. But maybe not.

You're a denier!!!

I agree you're probably right that it will keep warming, how am I a denier? But what's .7, isn't that a little alarmist?

You obviously have no clue and are a bitter-ender.

You don't agree it might possibly not keep going up?

You know nothing of science.

Uh, what's that?

It's a chart.

Yes, it shows the same .7 trend over the last 35 years as it does for the entire 126 which is what I've bascially been saying.

That's not science, it's your opinion.

I'm just looking at the numbers. Anyway, again, I just don't think it's that big a deal.

The IPCC thinks so, I think so, science thinks so!!!!

Those are opinions also.

You are obfuscatory and mendacitic in nature.

Well, okay. Thanks for the clarification of your viewpoints on the importance and impact. Good luck with your getting policy implemented.

By Robert S. (not verified) on 25 Apr 2007 #permalink

"Fair point. Raising fears with propaganda to get the masses reading all the news stories to worry about things (not that it seems much action is being demanded). Now that the public debate (I thought it was a discussion, but there you go) is over, all that needs to be done is something to get policy enacted. That's the trick, isn't it? Get the policy in place. That's not debate advice, it's a question of what you plan to do next, because nothing seems to be happening."

You mean other than the three carbon-trading bills currently before the US Congress; the imminent release of plans for a national trading scheme for carbon emissions here in Australia; China adopting some of the world's most stringent car emissions laws; and Great Britain has committed to a 60% cut in emissions by 2050.

The policy makers are persuaded, apart from a certain delusional cowboy in Washington, they were persuaded 9 years ago when they signed the Kyoto Protocol.

BTW Robert, I spent a decade as a policy officer in various government Departments advising government on various issues. I think I have a better idea than most of what's involved in persuading policy makers.

Oh and your misrepresentation of the tactics of the advocates of action to reduce global warming are wrong, vile and deeply offensive.

By Ian Gould (not verified) on 25 Apr 2007 #permalink

Robert S

In my previous comment, the main point that I was attempting to make was: what may appear as a very small change in climate can and does have substantial impacts. Many of these impacts are on the hydrosphere and biosphere. The same hydrosphere and biosphere that provide us with essential services.

I will address one point that you raise. How much error is in the data set. The data you examined was a combined land and sea record. The sea temperature data (ERSST) are described in:

Smith, T.M., and R.W. Reynolds, 2004: Improved Extended Reconstruction of SST (1854-1997). Journal of Climate, 17, 2466-2477. The paper is available on the NOAA website at:

http://www.ncdc.noaa.gov/img/climate/research/sst/ersst-v2.pdf

From the abstract: "The 95% confidence uncertainty for the near-global average is 0.4 C or more in the nineteenth century, near 0.2 C for the first half of the twentieth century, and 0.1 C or less after 1950."

Thus, there is less error in the data set in the most recent decades. The margin of error is small relative to the trend in anomalies. There is similar documentation available for the terrestrial data.

There may well be many reasons why you seem to advocate for inaction. However, there is no lack of quality data on the march of climate change and information on impacts.

BTW Robert, I spent a decade as a policy officer in various government Departments advising government on various issues. I think I have a better idea than most of what's involved in persuading policy makers.

I do it now, Ian, with a different title but same tune.

The decision-makers in the American West know global warming is helping to reduce our snowpack and helping to kill our trees, with vast economic impacts. They don't listen to wingnut cr*p about .5 this or .7 that. That's over, except for some loud bitter-enders on the Internets.

The problem is finding good leaders with political will.

One last bit:

Last week I spoke at a business conference about what the future held for this area, and the limiting factor for most of us is water. We have a hard build-out.

Now, these were big water users from back east, unfamiliar with the arid American West. So they listened. One guy in the audience tried to do the "AlGore is fat" routine after I explained about future water prospects, and that lasted about 4.06 seconds, until 3-4 of the others effectively told him to shut his yap.

Best,

D

"Last week I spoke at a business conference about what the future held for this area, and the limiting factor for most of us is water. We have a hard build-out."

Don't worry Australia knows all about that.

Irrigators in the Murray-Darling have been told they'll get zero-zip-nada water this winter since what little is left is all required for municipal water supply in the towns of the region.

Oh and the South Australia government just had to deny rumors they only had one months worth of water left for Adelaide.

By Ian Gould (not verified) on 25 Apr 2007 #permalink

So, may this self-doubting sceptic ("Were you at all introspective and not dogmatic, you might be experiencing a bit of self doubt" Eli asks above) ask a question of you-all exalted geniuses who know all there is to know about climate?

That is, I live in Australia, and I am very aware of the water crisis here. But can someone explain the relationship between AGW (assuming that it can be demonstrated) and water shortages? I don't understand the relationship, but I suspect that it is more complex than saying that higher T means less H2O.

Actually I think the people saying "although I have no qualifications whatsoever in climatology I know better than the entire world community of climatologists" are the ones who thnk of themselves as "exalted geniuses".

At the simplest level, water levels in waterbodies are determined by the balance between inflows from rain, catchments and groundwater and outflows from transpiration.

Even if rainfall levels remain unchanged, higher temperatures are likely to lead to higher transpiration and therefore lower water levels.

Secondly though, rainfall in a region is determined be a whole range of factors, such as the temperature of the oceans and ocean currents. Changing the balance between all those factors shifts rainfall.

As a whole, Australia isn't necessarily experiencing less rain in total - but rain in the inland west has increased dramatically in recent years - which isn't much help to the MDB. Similarly, Brisbane has received above-average rainfall this year - but it odes us no good because we get our water from dams inland and north east of the city where rainfall has dropped dramatically. It only requires the rain-bearing winds to shift a few kilometres on average to miss the catchments where we get our water from.

By Ian Gould (not verified) on 26 Apr 2007 #permalink

Dear Ian

You said: Even if rainfall levels remain unchanged, higher temperatures are likely to lead to higher transpiration and therefore lower water levels.

What happens to what transpired up? does it never come down again? If not where does it go? could it be clouds' cover and their cooling effect?

Tim C : Another paradigm shift What goes up,stays up
See also : tree rings are themometers

If temperatures increase and relative humidity stays constant, more will go up than comes down until a new equilibrium is established. Once more demonstrating for chrisl and trevor that it is not even what they don't know that labels them but what they know they know that is wrong.

Ian: I didn't mean to offend you, I appologize if I did. However, I wasn't talking about advocate tactics in general. I was commenting on the nature of the discussion here, which I imagine is similar to how others are treated on other blogs. And comments have been directed at me here in an offensive way quite a few times. For example, Dano's comment in #223, or yours in #204 to me, or in #226 to trevor, which I imagine is focused at me at least partially. "I know better than the entire world community of climatologists and therefore I am an exalted genius. My opinions are facts; proven, carved in stone, and the only possibilities." I don't think I ever said that, did I?

Did you talk to policy makers like that when you were in the business?

Bills, plans, committing to. China and their cars, well they had to do something, nobody wants all that pollution. Contrary to popular belief in some circles, countries usually do try to act environmentally responsibly on their own without having to be forced to; it makes sence on both health and economic fronts.

In any case, most of the action being taken is directed by economics, politicians wanting to look like they're doing something, or because of other practical matters, not necessarily or even because of global warming itself. Still it is action, and that's all that's important. I'd say in many ways, things are happening in spite of what WG II's been saying and how the rank and file has been saying it, rather than because of it.

Delusional cowboy? Hahahaha. That's funny. Seriously, the US Senate under Clinton refused to deal with Kyoto on something like a 95-0 vote. It's a poison pill for the US, nobody in their right mind there would agree to it.

JP:You're the kind of person that needs to be "talking this up", it's a way of "speaking" that is taken seriously.

It still seems as if a rise of ~100 on CO2 should have more effect then it has: regardless of the effect even a "small" rise in temperature mean has it seems that rise should have been greater. (As in, the effect is one thing, the amount of rise is another issue)

However, I suppose the absorbtion of CO2 into the oceans, the amount of plants that have been grown, and the effects of aresols (as well as certain other factors) has been masking a lot of the CO2 effects, at least so far.

Two questions I have are

1. Is it possible the rise in temperature trend is actually partially due to improving the EOM from .4 to .1

2. Is it possible that the effects are being overestimated (or overstated) to the extent it makes people doubtful of the extent that mitigation is required, impeding progress rather than accelerating it?

As an aside, I'm not really advocating inaction, I'm just saying I think we might be too hasty about it, and therefore might not be doing the correct things.

Dano: All I asked was if the rise was a big deal, it's others who started picking at the numbers rather than answering the question I asked. I spent all my time trying to clarify what I was asking based upon the nit-picking of others. Most of that conversation was not my idea, so if others don't want to get into the details, don't start a discussion on details. Not my fault.

And geez dude, sorry you're low on water, but that's not my fault either. Maybe you should move to where there's more water? I mean, I like the area around Alice Springs, but I wouldn't live there.

Oh, I forgot, you're not listening to me any more. Never mind.

By Robert S. (not verified) on 26 Apr 2007 #permalink

JP: In addition, as Dano wrote in #68 correctly, albiet in a condesending manner, the "society train" is already forcing a number of actions on this. (Given the idea of a society train, I have no idea why those on it don't answer questions and instead attack anyone asking them anything as being a heretic. And they seem to have a strange way of ignoring those who "missed the train" it seems.)

Anyway, a lot of these actions involving either mitigation, adaptation or both started a long time ago. This current bizarre focus on AGW, or the science behind it, as if they were important on their own; as if they were goals? It's a distraction. What are the goals? A cleaner more efficient and self-sustaining environment, better sources of energy, a better understanding of the mechanisms by which the planet runs. Things of that nature.

Take for example automobiles. The trend has been greater fuel economy and less emissions for quite a long time, based mostly upon economic factors. It doesn't take a genius to realize that supply/demand and prices makes it make sense to lower the use of gasoline. It was clear quite a few years ago that harmful rain, quality of life, and the associated medical costs showed that too many emissions were a bad thing -- polution, acid rain -- and states have been dictating a number of mitigations far before anyone even put the letters AGW together. Each state passes laws based upon their own situation, with the federal government passing overall minimums for everyone. (Which is how it works now still -- making this "Bush is doing nothing" mantra a little perplexing -- That's what the USDA, EPA, DOT et al do, which are created by the Executive branch, but operate according to directives from the Legislative branch. Since Congress is doing things, what does the Executive need to do?)

The same thing has been happening with industry; the states have been regulating things depending on the factors in their states, and the federal government overall sets minimums. Business found out that it was bad PR, bad for customers, and bad for their bottom line to pollute, along with some help from fines and cleanup costs. So they got better at being green (and have since found out there are actually economic benefits to it, so have done more on the side of convservation and environmental friendliness).

In fact, that's why there's all this talk on cap and trade, limits on CO2, carbon taxes and the like -- there's big big money in it. And business realizes it, and jumps on the bandwagon -- bad news for all those that hate the "evil corporations" and their "obscene profits". (As an aside, when an oil company makes 14 cents on a gallon of gas, the US and state governments make about 55 cents....)

I do question what a "carbon tax" might do to the world economy, but that might be the best way to go, certainly a lot of the other methods are expensive also. But that's another issue, an economics one.

Anyway, here's how strange this entire subject has gotten, given that there's already so much going on by itself. The Supreme Court recently narrowly got involved at the policy level by telling the EPA the Clean Air act gave them the power to regulate "vehicle emissions for carbon dioxide, methane, nitrous oxide, and hydrofluorocarbons" because MA sued the EPA over it. (How the original 19 private companies that sent the EPA the 1999 petition mistook chloro- for hydro-, don't ask me, but obviously the justices don't know the difference between them either) Here's the entire opinion, the EPA's position, and the dissenting opinions. I thought it made for interesting reading, even though I'm not sure why they bothered with it.

http://www.supremecourtus.gov/opinions/06pdf/05-1120.pdf

So basically 5 people told the EPA "You have the power to regulate this stuff, so relook this, and tell us if you think there's a profound scientific uncertaintly." and 4 people basicially said "It's not our business, but even if it was, they already did say it."

"In 2006, carbon dioxide levels reached 382 parts per million a level thought to exceed the concentration of carbon dioxide in the atmosphere at any point over the past 20 million years."

"A well-documented rise in global temperatures has coincided with a significant increase in the concentration of carbon dioxide in the atmosphere. Respected scientists believe the two trends are related."

"... an essay requirement: "If," the Court says, "the scientific uncertainty is so profound that it precludes EPA from making a reasoned judgment as to whether greenhouse gases contribute to global warming, EPA must say so." Ante, at 31. But EPA has said precisely that -- and at great length, based on information contained in a 2001 report by the National Research Council (NRC) entitled Climate Change Science: An Analysis of Some Key Questions"

Here's the short and sweet of the decision:

The majority opinion of the Supreme Court (5), in 3 parts

1. States had the right to sue the EPA over the decision not to regulate GhG.

2. The Clean Air Act gives the EPA the authority to regulate GhG.

3. The EPA must re-evaluate the contention it has the discretion to not regulate GhG.

The dissenters(4), in 2 dissents

1. Dealing with the complaints spelled out by the state of Massachusetts is the function of Congress and the chief executive.

2. The court should not substitute its judgment in place of the EPA's.

By Robert S. (not verified) on 26 Apr 2007 #permalink

Here's some of the work now being done, or questions now being asked, to make whatever it is we do, for whatever reason it is we do it, make the most sense.

Los Alamos Nation Laboratory on sequestering carbon
http://www.lanl.gov/news/index.php/fuseaction/home.story/story_id/2443/…

Costs of taxing carbon to economies http://www.theage.com.au/articles/2004/08/16/1092508369366.html?from=mo…

USDA economics of sequestering carbon http://www.ers.usda.gov/publications/tb1909/

Pro/Con of sequestration
http://pubs.acs.org/hotartcl/est/98/jan/carbon.html

US work on sequestration goes on http://www.wired.com/science/discoveries/news/2004/11/65852 (fact check -- as a blanket statement with no qualifications, water vapor is the principal greenhouse gas. They probably meant carbon dioxide is the principal greenhouse gas when it comes to forcing or that carbon dioxide has a greater effect by volume than equal amounts of water vapor)

Japan plans to bury 200 million tons of CO2 a year by 2020, starting as early as 2010
http://www.usatoday.com/tech/science/2006-06-26-japan-greenhouse-gas_x…

I almost forgot. Here's some of the things the EPA, DOE and others are saying or doing already (given my comments about SCOTUS and Bush, etc)

http://www.epa.gov/innovation/directory/tech.htm

http://www.epa.gov/etop/

http://www.climatetechnology.gov/

http://www.climatescience.gov/

http://www.whitehouse.gov/news/releases/2005/05/20050518-4.html

By Robert S. (not verified) on 26 Apr 2007 #permalink

Ahh, Robert, your still ignoring everything we say.

For starters, it is not an opinion that we are currently warming the planet with CO2 emissions, and that if current trends continue, it will be around 3 degrees warmer in 93 years time. Do you disagree?
If you do, what evidence do you have to back you up?

I couldn't care less what your doing graphing temperatures. Your pulling numbers out your arse, as Donald says on the Lancet threads.

Mind you, you do seem to have discovered thermal lag on your own. Thats a good start. Thermal lag is when you have heat sinks like the ocean retarding warming due to taking in all the spare heat. And what do you know, the oceans are warming!

A question for everyone else- hands up those who think the only reason to keep talking to Robert is to prevent him spreading confusion elsewhere?
*raised hand*

Ian: I didn't mean to offend you, I appologize if I did. "However, I wasn't talking about advocate tactics in general. I was commenting on the nature of the discussion here, which I imagine is similar to how others are treated on other blogs. And comments have been directed at me here in an offensive way quite a few times. For example, Dano's comment in #223, or yours in #204 to me, or in #226 to trevor, which I imagine is focused at me at least partially. "I know better than the entire world community of climatologists and therefore I am an exalted genius. My opinions are facts; proven, carved in stone, and the only possibilities." I don't think I ever said that, did I?"

"Exalted geniuses" is a direct quote from Trevor at 225.

By Ian Gould (not verified) on 26 Apr 2007 #permalink

Tim C: "You said: Even if rainfall levels remain unchanged, higher temperatures are likely to lead to higher transpiration and therefore lower water levels.

What happens to what transpired up? does it never come down again? If not where does it go? could it be clouds' cover and their cooling effect?"

See El's response at 229. Increasing the temperature will increase the atmosphere's capacity to absorb water vapor.

The majority of the water in the atmosphere isn't in the form of clouds and cloud formation is dependent on far more than just humidity. Other relevant factors include the presence of nucleating particles; convection patterns and wind patterns.

So yes Tim, some of it does "stay up there".

By Ian Gould (not verified) on 26 Apr 2007 #permalink

Ian said at 234:"Increasing the temperature will increase the atmosphere's capacity to absorb water vapor". Indefinitely, or to how many ppmv before we drown?

It's a big atmosphere and an exponential vapor pressure curve. More seriously the stuff hits the fan when water vapor sneaks through the cold trap at the tropopause and HOx cycles whack the ozone.

Ian:

Oh and the South Australia government just had to deny rumors they only had one months worth of water left for Adelaide.

We're getting a spate of stories around here about the impacts of the state of Colorado cutting off water to irrigators. Just yesterday morning I listened to some guy out on the plains enumerating the economic costs and ancillary impacts of cutting off ag's irrigation.

All true. All because of no water. And no budging after the call to costs.

And I just wrote my monthly report that included my presentation where I said there's no water for big water users. We're in a go-go County where permits pay the way and pave the streets with gold. My director had no problem with my being blunt to big business about water.

Best,

D

Robert S:

"Go to http://www.ncdc.noaa.gov/gcag/gcag.html

On that page, Time Series "Global" and "GHCN-ERSST" as the dataset.

Click "Submit"

Click "Create Graph" and wait. (The defaults are the lon/lat for the globe from Jan 1880 to jan 2006 on a line plot.)

The chart will come up, interactive with numbers on the data points and the chart with the data points below that."

At long last we're making some progress after I first brought this problem up a long time ago (but as usual was ignored). Robert S is getting the temperature series for Januaries, not whole years. If Robert S had been more familiar with old-fashioned temperature series such as the NCDC's Global Temperature Anomalies, he probably would have noticed something funny about the data he used by himself. In any case he was talking a lot more noise than signal.

"Why is .7 C over 35 years something I need to worry about"

Like saying, "Why is the thin end of the wedge something I need to worry about".

By Chris O'Neill (not verified) on 27 Apr 2007 #permalink

Guthrie, in #208 asked about CO2 sequestration via phytoplankton, after seeding the southern ocean with iron. Turns out that idea has been tested, and unfortunately, reuptake mechanisms are so efficient that dead plankton don't vanish to the bottom, but get scavenged, so no sequestration. Here's a link to description:
http://aphriza.wordpress.com/

Thanks Stewart, that url is very interesting.

"Why is .7 C over 35 years something I need to worry about"

Robert, you know how when you turn on an electric heater it takes time for the room to warm up?

That's thermal inertia.

The Earth has a LOT of thermal inertia. About 80% of the increased hat from more greenhouse gases is absorbed by the oceans (and some of it is used up by additional water transpiring into the atmosphere).

So it takes decades for an increase in net thermal energy to feed through into higher atmospheric temperatures, The warming we've seen to date represents the effects of carbon dioxide emissions in the 1970's and 1980's.

Carbon dioxide emissions have increased dramatically since then so we know there's an extremely high probability that global warming will get worse (i.e. the rate of warming will accelerate) even if we start reducing emissions now.

Furthermore, climactic extremes are also increasing. What kills people isn't the 0.7 celsius average increase - it's the heatwaves and droughts.

By Ian Gould (not verified) on 27 Apr 2007 #permalink

Thanks Eli (at 229) - but you have still not anwered the questions of (1) what the carrying capacity of the atmosphere for water vapor is in ppmv, (2) the current rate of increase of that water vapor, and (3) when will that limit be reached given your exponential increases in your answer to (2)?

Robert S: Just so you know: My reference in #225 to "you-all exalted geniuses who know all there is to know about climate" was directed to Eli, Mr Lambert, Guthrie and all of the others who are attacking you. I am on your side.

I posted a post (censored) that said of all the posts in the above thread, one poster is calm, consistent, rational and objective (you). Because of that I doubt that this post will be allowed.

Ian said (at #243) What kills people isn't the 0.7 celsius average increase - it's the heatwaves and droughts.

Like the coolwave I have just experienced in PNG, waking up in POM freezing to death at 1 am and being met in Western Province by people wearing jackets, unheard of in my time there, and with reefs exposed by falling sea levels? or the wettest April in the 8 years I have been keeping records here in Canberra? Did you ever hear of Joseph and his amazing technicolored dreamcoat plus 7 year cycles?

Is Tim trying to make the point that more extreme and confused weather is not a prediction of global warming?

I'm not sure what point Tim C. is trying to make.

I fear that he isn't either.

By Ian Gould (not verified) on 30 Apr 2007 #permalink

Guthrie: my questions are (1) what is the carrying capacity of the atmosphere for water vapor in ppmv, given that atmospheric H20 may well be increasing more rapidly than CO2? (2) what is the current rate of increase of that water vapor? and (3) when will that capacity limit in your answer to (1) be reached given Eli's exponential growth rate for increases in the water bearing capacity of the atmosphere?

Shorter Timmy C:

Guthrie: chase down my red herrings or I'll accuse you of some bad words in order to boast I gained rhetorical advantage.

Otherwise, ignore at will.

Tim L: I use FF and reject cookies manually. For some reason, your particular blog on SciBlogs pushes 5 cookies with each hit on your blog.

Cease and desist this nefarious practice, sir.

Best,

D

Dano, is this new? Do you get that many from other Sciblogs? The only thing that I'm doing that might be different is the sitemeter at the bottom of the page.

"what is the carrying capacity of the atmosphere for water vapor in ppmv"

As close to 1,000,000 as you like. "Exponential increase" refers to vapour pressure BTW but some people have not yet been educated in the difference between vapour pressure and ppmv.

By Chris O'Neill (not verified) on 30 Apr 2007 #permalink

So Tim, are you trying to say (bearing in mind I am merely an interested member of the public) that water vapour increases are causing problems with the weather?

Re: #29: Thank you Eli for your patronising response. "Once more demonstrating for chrisl and trevor that it is not even what they don't know that labels them but what they know they know that is wrong."

Facts. I am agnostic on the issues. So why don't you respond to my question??

Guthrie (254). Yes, if CO2 increases that are minuscule and barely perceptible are outweighed by larger increases in water vapor, why are we not told about the latter by IPCC, who instead insist on ever more severe droughts acros the planet? The "Science" even tells us that water vapor is a more potent greenhouse "gas" than CO2 - but as we see here cannot provide answers to the simplest questions. Chris O'Neill's response is to say that H2O could even reach 100% of the atmosphere without being inconvenient!

Here's some chemistry:

With butane (C4H10), albeit before allowing for atomic weights, you have

2C4H10 + 13O2 = 8CO2 + 10 H2O

When will we drown a la Chris O'Neill? Why are CO2 emissions seen as more the culprit than H2O, given that the latter is already 3 times more prominent and even more potent than that as a GHG in the atmosphere, as well as growing more rapidly if Eli is right?

Tim,

IIRC, I get 5 from sitemeter and 5 from sciblogs. FF allows you to apply your choice in the future, and I have, & I thought I'd pass on the info. I read 3-4 others here at sciblogs and yours is the only one that does this. If you wish I'll enable cookies again and give details...

Best,

D

Wow.

I am beginning to think the Curtin character is a parody character.

Water vapor has increased by greater than 33% in the atmosphere. According to Timmy's logic in 256. Maybe the clouds are following around the delusionists, because I don't see 33% more water vapor in my atmosphere.

There is strong evidence that the Curtin character is a parody character.

Best,

D

""what is the carrying capacity of the atmosphere for water vapor in ppmv"

As close to 1,000,000 as you like."

I was, of course, referring to the limit set by the laws of physics, something that some people are blithely ignorant of.

By Chris O'Neill (not verified) on 01 May 2007 #permalink

Trevor, playing the victim bully is not a winning game with a bunny

'victim bullies,' who use claims of having been wronged to gain leverage over others.(pp. 123-4) Unlike simple passive-aggression, victim bullies use accusations as weapons, and ramp up the accusations over time. Unlike a normal person, who would slink away in shame as the initial accusations are discredited, a victim bully lacks either guilt or shame, honestly believing that s/he has been so egregiously wronged in some cosmic way that anything s/he does or says is justified in the larger scheme of things. So when the initial accusations are dismissed, the victim bully's first move is a sort of double-or-nothing, raising the absurdity and the stakes even more......

Tim dear, use the Clausius eq and plug in

dp/dT = p DHvap/RT^2 where p is the saturated humidity, DHvap is the molar heat of vaporization, R is the gas constant 8.314 J/mol-K and T the temperature in Kelvin.

This yields the change in saturated vapor pressure per degree change in temperature. While not all of the atmosphere is saturated (little besides the marine boundry layer is), everything pretty much scales for constant relative humidity.

For the curious onlookers out there, here is a qualitative description, from basic first principles, of the point that Tim Curtin seems to be trying to obscure - indeed, in some ways, actively misrepresenting. The money point is at #7.

1. Warm air can hold more water vapor than cold air - in Curtin's language, the 'carrying capacity' of water vapor is higher for warmer air. This is simple basic physics.

2. Water vapor can be measured in two ways: as absolute concentration in the air in parts per million volume (ppmv), or as relative humidity - the % concentration relative to the maximum that the air can hold.

3. Water vapor is a greenhouse gas. The absolute concentration in ppmv is the relevant measure for the "greenhouse effect" of water vapor. Relative humidity doesn't matter here - it doesn't matter that the air is 50 % saturated with water vapor, it does matter how many water vapor molecules are absorbing IR.

4. Relative humidity is the primary relevant measure for weather. Warmer air can hold more water, so if air gets warmer and has the same absolute water vapor concentration in ppmv, the relative humidity decreases. Clouds form at approximately 100% relative humidity (yeah, this is oversimplified a bit). The relative humidity is very important to weather, but the absolute concentration is relatively unimportant to many weather processes.

5. Warmer air (say, from warming due to increased atmospheric CO2) can have a higher absolute concentration of water vapor (in ppmv) with no increase or even a decrease in relative humidity (in % of saturation). That is, there can be more water molecules in the air , but not enough more to actually stay at 50% of the new higher saturation concentration in the warmer air. There can be increasing atmospheric temperature, and increasing number of water molecules being evaporated into the air, while also having constant or decreasing relative humidity.

6. Because of all this, warming from increasing CO2 can cause increased evaporation and increased absolute water volume in the air (in ppmv), and this will have the effect of amplifying the initial warming from the CO2. At the same time, the relative humidity might increase, remain the same, or decrease - it is entirely possible to have more water vapor in ppmv, causing increased warming, and simultaneously lower relative humidity causing deceased cloud formation and decreased rainfall.

7. The amplification from water vapor is not a runaway positive feedback process. If it were, any local increase in water vapor concentration would lead to runaway warming, and the planet would long since have turned into a steam bath. It has not - this alone tells us that the gain on the water vapor warming amplification is limited. There are limiting mechanisms that cause the increase to tend to a new, somewhat higher 'equilibrium' for water vapor concentration (ppmv) at a somewhat higher temperature.

7. Curtin knows this, and when he asks of the amplifying feedback "to how many ppmv before we drown?" he is being actively misleading.

Not exactly on topic but seeing as Tim c. is reading this and he constantly insists there's no possible source of baseload power other than coal and nuclear (except hydro; and biomass and geothermal and...)

http://www.wizardpower.com.au/Wizard_Power_AEST_Announcement_Press_Rele…

"Federal government awards a $7.4M grant for a baseload solar power project

Australian company Wizard Power plans to build a oncentrating solar thermal power plant with integrated solar energy storage near Whyalla in South Australia. The project will demonstrate solar energy storage solution that, when combined with highly concentrated solar power, can
deliver emission free, multi-megawatt baseload or on-demand peak electricity generation."

By Ian Gould (not verified) on 02 May 2007 #permalink

Chris: That is an odd little thing to do there on the page, default to January only. Now I see that's why it was so strange that everyone was telling me I was making up my numbers. I appologize I didn't understand it defaulted to that; and I thought we might be not talking about the same thing. I'm not *trying* to make anything up or be anything other than transparent. Once you said that, it's very obvious. And the chart is different, for sure. That said, if everyone wasn't so adversarial, and had gone to the NCDC data and pointed out my error, maybe we could have avoiding all this pointless bickering..... Well at least next time, you can point that out and you won't have to go through it again..... If I missed you saying I was only getting Januarys, I appologize for that also. I stand corrected, you were correct and I was mistaken.

However, when I did all year, anyway, it's actually less on two of the three. Sure, the temp now is .5 (instead of .3) but the trend line is .6 instead of .7 and the trend is .04 C per decade instead of .05

I'm rather unclear how it's impossible to consider that not everyone agrees at the import or draws the same exact conclusions as everyone else. Certainly there are a number of scientists and policy makers and panels that disagree, some of whom are like me, mainly agreeing with everything but a few points, and about exactly what actions to take.

Ian: I am aware of the lag time as well as the ocean effects. And the role of clouds, and taken as a whole most all is water vapour, but it's a feedback not a forcing, and CO2 and CH4 have a greater effect respectivly, etc. Yes water can hold a lot more energy than air. I'm quite aware of most of the science behind it. Am I an expert? No. Neither are most of the folks in the common population, who are your audience, if you're trying to talk to anyone not on the blogs. I am not a denier, nor am I a skeptic. I'm just unconvinced this is a problem. It is 100% for sure warming, and the evidence points to CO2 is probably the major contributor, and we create CO2. Hence AGW. Plus no matter if it's warming, or not, or if we're causing it, or not (or in other words regardless) I still say we should take both mitigation and adaptation measures. So I am wondering since I am advocating action, why all the debate is about the details, and what exactly you think I'm arguing about from a science standpoint? I agree with you. We just disagree about the import.

But I'm saying we should do something anyway, regardless! I just don't understand the hostility. [shrugs] So again, if you treat people that basicially agree with you this way, how are you going to convince the people with the money....... *I'm* not saying I know more than climatologists, because I quite clearly don't. I'm talking about policy here mainly.

trevor: Ah, sorry, sometimes it's difficult to see who's saying what why about whom. Actually, I was commenting on what Ian said to you in 226! I should have written it more clearly "...or your comment [speaking to Ian] in #226 to trevor, which I imagine [Ian's jibe] was directed at me at least partially" Thanks!

guthrie: I'm not ignoring you. In #232 I'm just telling you all the work the US and some others are doing on the subject. (Sorry tho, I don't know if The Age is liberal or conservative) For starters, the link between CO2 and warming has not be proven it's what, 90%? Or guessed at being 90% sure? So yes, if you extrapolate, if we do nothing, and if everyone's correct, and if current trends continue, and if no new technology or fuel sources come into play and if whatever, I'm sure it will rise 1-6 degrees at the high ends of some of the IPCC figures. I'm just not as sure as you are that all those trends will, in the next 100 odd years.... I think we'll see some clearer signs soon. But in 100 years? We'll all be dead! Or sooner, if oh, let's say, hmmmm..... Nuclear war? I'm more worried about that, myself. But thanks for raising your hand at me and not your finger.

Yes it's warming! I never said it wasn't.

By Robert S. (not verified) on 02 May 2007 #permalink

Now I'm going to tell you my opinion exactly why nothing anyone says here or anywhere, "pro" or "con" or neutral matters in the grand scheme of things. We are "discussing" the wrong thing.

I'm taking that since everyone's ignoring the fact the US is doing a great deal of work on this "issue", as I posted links to and then had the subject changed on, that you don't think it's enough for them to be doing on it. Okay. Fair enough. If I'm mistaken with my conclusion, that's okay, sorry if I've miscategorized it. And in my opinion they're doing more than the 20% of the CO2 they expel, and x% amount they sink actually calls for them to do to either adapt or mitigate to it.

I'm taking it since everyone's basicially ignoring that the "undeveloped" world is creating 50% of the CO2 and doing nothing about it, that it's not an important topic. I'll take it for granted, since it appears that way. Doesn't matter, it's really immaterial.

Regardless of what you think of the United States, if they don't do "anything", nobody will. Plus, there are far too many people at all levels of industry, academia and government that will not do anything, not just in the US, but in every single country that makes up the "western world", no matter what they say to the contrary. A massive PR campaign in Canada was needed to push them to Kyoto. If I remember correctly, at first even Australia was not going to participate. (And no, I don't know the details of what arm-twisting was taken to make them.)

That's not important either. The US is never going to sign on to anything like Kyoto, ever. And I'm more certain of that than I am ambivalent of the rest of the case - because the rest of the case is not the issue. Under Clinton as president, the Senate rejected taking action 95-0 -- BOTH parties. Since the US Senate (in case you didn't know) has to approve any treaty, no matter who's in power either in Congress or the Presidency, no treaty like Kyoto is ever going to fly with that kind of reaction from the US. I'm sure the rest of the world is enjoying blaming them, because then nobody else has to take the heat. Blame Bush, blame Bush, no WMD in Iraq, blah blah blah. PR.

Further, although the Democrats hold a slight majority in the US House, they are currently unable to pass (not suggest) many of the seemingly meaningful regulations brought up, because not even they have unity on the issue (nor a clear mandate). They just have to look like they are doing something. The liberals in the US aren't even buying into this, not if it affects energy. (They like refrigerators and central air themselves.) Add to that the fact that energy is the driver of the world economy, who's going to slit their own throat by doing something wasteful with money that's going to give their competitors a clear advantage? Yep, a lot of talk and no action. Even the US Supreme Court, in a narrow 5-4 vote, only told the US EPA to "relook the issue".

Forget all that even. The most influential conservative AM radio talk show host in the US (who probably has more listeners than, say, the entire population of England) is currently railing against AGW as being a bunch of BS. (I don't agree science-wise, as I stated, at least not to that degree of certainty) There is no traction there, regardless.

Add to that the most influential libertarian radio AM talk show host in the US is also calling it BS on a regular basis.

I would talk about liberal AM radio talk show hosts in the US but there aren't any. But if there were, they'd be silent about it. They don't want it either -- 95-0 out of about 50/50 conservative/liberal Senate vote, remember? And that was with Al Gore as Vice-President! If even his own political party is not agreeing with the points of his later Academy Award winning documentary, at least on an action basis, what chance does the future hold?

There are simply too many people in the world that think this entire subject is about a transfer of wealth from those that are doing well to those that aren't. You may think it's all just "conspiracy theory". Maybe it is. But belief and motivation is a powerful thing, no matter the truth. It's all about perception and emotion.

Oil is the lubricant that makes the world economy go around, and while some people complain about the power of the energy companies, they have a lot of money. They are going to drive the train. Period. As if anyone is going to willingly give up electricity, air conditioning, automobiles, plastics or the like. I doubt it. I won't, and neither is anyone else. Al Gore won't even! (Oh yeah, whatever he uses in his mansion, he'll plant trees to soak up, uh huh) We have this amazing capacity to do what we want. Any of you smoke? Know what the science says about it? Yep.

I don't care where you live, it's not going to happen. Economics is power and power is economics. Let's say you cut the GDP or GNP of a country in half. That is going to affect every single other country in the world. Remember a few years back when there was a fire in 1 (one) resin plant of the 4 (four) that make resin for RAM. What happened? RAM prices doubled. So now businesses and consumers are paying more for RAM. Double whammy, now businesses that are paying more for RAM charge consumers more. Worldwide. This is a global economy.

Why do I bring that point up? If you can't chart the complex interactions on either a micro- or macro-economics level, how the hello do you figure out what the weather is going to do in 100 years? And how do you get everyone to go along with things like this?

You don't!

{rant over}

By Robert S. (not verified) on 02 May 2007 #permalink

Lee (#262): many thanks indeed, very educational (for me. I still think water vapor effects have been understated.
Ian(#263): more of same (on storage for solar) in today's Canberra Times. What are the costs per MWh including storage costs?

http://engnet.anu.edu.au/DEresearch/solarthermal/pages/pubs/SolarEAmmon…

Quote: A detailed study of a hypothetical 10 MWe baseload
power plant in central Australia, has indicated that
Levelised Electricity costs less that AUS $0.15/kW h are
potentially achievable...

The storage system is about as simple as any chemical system you've ever seen. Ammonia is dissociated by heat into nitrogen and hydrogen gas which are then stored before being fed into a reactor where they recombine exothermically.

15 cents per kilowatt is obviously well above current generation prices (although much cheaper than current remote-area diesel sets). But it includes the storage cost so in theory you could sell the power for peaking demand.

Of course, you're avoiding carbon dioxide emissions. Generating s kilowatt of power from black coal apparently generated around 750 grams of carbon dioxide:

http://www.dw-world.de/dw/article/0,2144,2396828,00.html

According to the IEA electricity costs in Australia were between $A0.08 (industrial) and A$0.13 (residential) - that's converting into Australian dollars at US$0.75.

Assuming a retail cost of solar-generated power of A$0.20, a consumer is paying a 7 cent premium to avoid emission of 750 grams of carbon dioxide.

That works out to around A$93/US$70 per tonne of carbon dioxide avoided.

You'd hope that cost would come down with time, due to economies of scale and further technological improvements but given that the supply of cheap land; sunlight and ammonia in Australia are all virtually unlimited, you'd be effectively putting a lid on all abatement and sequestration costs of $93 per tonne.

By Ian Gould (not verified) on 02 May 2007 #permalink

Robert S: "and the trend is .04 C per decade instead of .05"

There's something a bit strange about that 0.04 C figure because 0.6 C in 125 years is 0.048 C per decade so it should still be 0.05 to one significant digit.

Regarding trends, if you get the trend for 1880-1930 then it is zero degrees per decade and for 1930-2005 it is 0.07 degrees C per decade (the value says 0.06 but again that disagrees with the graph which says 0.07). On that basis there wasn't much long-term warming until sometime around 1930. If you get the trend for shorter periods in the past then it usually keeps increasing the more recent the starting date e.g. for 1977-2005 the trend is 0.16-0.17 degrees C per decade. These observations are consistent with the fact that the growth rate of atmospheric CO2 is accelerating and hence the long term growth rate of global temperature should also be accelerating.

By Chris O'Neill (not verified) on 03 May 2007 #permalink

Right, yes. Well, as I said, of course more than likely CO2 is causing warming (at least to some degree), and we would expect more of the same. It's certainly trending that way, and we are creating a lot of it regardless.

I just don't think long term that BAU is going to happen, and at least to me, the situation doesn't seem static. It's good that things are being done and there is awareness of it to the point where so many are becoming involved. Although since it's all basically a loop, H2O as vapour, water and ice, CO2, O3 and CH4 all in some way feed off each other. Factor in solar variations, wind patterns, UHIs, deforestation, disolving vegetation, etc, it's difficult to tell exactly what's happening, at least to degree. We know a lot of this, and best guesses are probably mostly correct. How to nail it down to specifics is more difficult. :)

We should reduce the amount of CO2 being produced and/or get rid of some of it, as well as increase fuel economy, decrease vehicle and industrial emissions of polutants, and work on alternative fuels. I don't think anyone's saying having a cleaner and healthier Earth is a bad thing! I think a lot of the biofuels and fuel cells are going to become more and more important, and that's not a bad thing either.

All in all, not doing anything at all is not an option, but rushing into things before knowing what unintended consequences are awaiting us could be worse than doing nothing, at least short term. It all boils down to not just money, but political will, as well as a general outlook upon things. We need to spend most of our time looking at solutions and not details....

As far as the graphs, I think it's simply removing the decimals rather than rounding. In a way, if you're discussing long term trends, .05 or .06 a decade is probably close enough especially given that we're measuring a global mean. How does that go in engineering? "If you care about the third significant digit of tensile strength, you are already in trouble."

Cheers.

By Robert S. (not verified) on 03 May 2007 #permalink

Chris O'Neill, I guess I have long since lost track of the graph that you and Robert S are arguing about. However, in Tim's post here it looks like the long term graph of temperature has the warming starting sometime just before 1910 (as opposed to 1930). It sure looks like the growth rate from 1910 to 1940 was pretty similar to the growth rate we have had for the last 30 years or so. It appears to be a bit higher more recently than it was 100 years ago. Certainly less than I would expect given how much more CO2 is in the atmosphere now than there was in 1909. I would say that according to Jones, we have had pretty steady temperature growth for almost 100 years, with the "aerosol affect" period from 1940 to 1975 breaking things up in the middle.

By oconnellc (not verified) on 03 May 2007 #permalink

Robert S.

Rush Limbaugh has a radio audience of about 10 million, so nowhere near the population of England, which is just over 50 million.

Oprah Winfrey has an audience of something like 30 million, and she was talking about using energy efficient compact fluorescents on her TV show.

Over to economic modelling v. climate modelling.

I have a postgraduate degree in an economics related discipline, and have worked as a professional economist.

The difference between the 2 subjects is that climate modelling is based on real science, that you can demonstrate in a lab. Real physical and chemical principles. There is no doubt that the models in climate science work as approximations of the physical world.

(it's actually easier to forecast climate than weather, because the chaos effects drop away over time, but that's another issue).

By contrast economic models are entirely based on assumptions. We don't know what will happen if the money supply increases. To inflation, to the exchange rate, to labour supply.

We *do* know what happens if you increase CO2 in an atmosphere, it blocks the reradiation of infra-red light.

The climate science world was a real breath of fresh air when I first began reading about it: climate scientists know so much more about the physical world than we do about the economic one.

And whereas humans are the most difficult part of any economic model, because they *adjust* their behaviour in response to policy, the climate just carries on regardless-- the physical laws of the universe don't change.

The uncertainty in climate models should make one *more* cautious about dumping CO2 into the atmosphere, not less. Because there is a significant chance the models have missed feedback effects, and things are going to be much *worse* than we forecast.

You don't care about the symmetric 'optimists' case as much, because then you've just wasted money. But if we blow out the parameters of the models on the other side, we've lost our ability to maintain our civilisation.

Uncertainty makes one more cautious, not less.

By Valuethinker (not verified) on 03 May 2007 #permalink

"I just don't think long term that BAU is going to happen, and at least to me, the situation doesn't seem static."

Certainly not static. CO2 emissions are still accelerating. I don't think BAU is going to happen long term either, but changing some time this century would be nice.

"if you're discussing long term trends, .05 or .06 a decade is probably close enough"

While it's nice to know that global warming a long time ago hasn't always been very fast, it's probably more important to note that the trend has accelerated to 0.16 degrees C per decade for the last three decades and is probably still accelerating.

By Chris O'Neill (not verified) on 04 May 2007 #permalink

Chris, I think you are right in that the warming has accelerated to .16 degrees C per decade. What has it accelerated from? Looking at that graph by Dr. Jones (I always think of the Nazis talking to Indy whenever I read "Dr. Jones") it looks like from 1910 to 1940 it was about .13 or .14 degrees C per decade. I wonder what percent of each of those numbers is due to anthropogenic CO2? I wonder what the 95% confidence interval is around each of those numbers? Or 90% confidence interval?

By oconnellc (not verified) on 04 May 2007 #permalink

"it looks like the long term graph of temperature has the warming starting sometime just before 1910 (as opposed to 1930)"

Indeed it did and there was also cooling from 1880 to 1908 with the net result being that from 1880 to 1930 there was neither long term cooling nor warming.

"the warming has accelerated to .16 degrees C per decade...

it looks like from 1910 to 1940 it was about .13 or .14 degrees C per decade. I wonder what percent of each of those numbers is due to anthropogenic CO2?"

Have a look at the graphs at the top of this page and you'll see how much the IPCC thinks is due to all anthropogenic forcings (figure SPM-4). There was very little net effect before 1950 so the global temperature variation until then was pretty much the natural variation. If this natural variation had continued, the earth should have gone back below the average of the 1880-1930 period at least for a few years but it didn't go back down very much at all. Natural variation would give similar magnitude ups and downs but now the ups are much bigger than the downs.

There is a graph in this article that shows how forcings (and consequently long term variations in climate) have varied since 1850.

By Chris O'Neill (not verified) on 05 May 2007 #permalink

Chris, once again, this is just boys talking over drinks... but looking at those graphs doesn't really give me much confidence in the models. Pre 1950, there isn't much agreement between the blue region and the plotted global temperature. At the beginning of the graph, the black line is either at the bottom, or below the 5% boundary of the blue region, and by some year (maybe 1940?) it is well above the 95% boundary. I don't think I would place much stock in any conclusions drawn from that blue region.

So, I'm looking at those graphs, and I don't see anything that tells me how much of that pre 1950 warming is due to anthropogenic CO2. Nor do I see anything that tells me the confidence interval on the plot of the actual temperature. Did I miss something?

Now, since the plots above don't really show any data pre-1900, I will go back to the Jones plot that Tim posted for us. Looking at the plot of temperature and comparing the pre 1950 period, I have to differ with your claim that there was no net effect before then. Starting with the beginning of that graph, there certainly appears to be a trand from 1855 to 1910 where the temperature bounced around between -.3 and -.4 Then, starting at 1910, there was a pretty significant looking change. The temperature in 1950 looks at least .2 degrees warmer than almost any time in the 1855-1910 period.

Regarding the forcings, that is a neat plot. But it is weird, the net forcings in 2000 is more than double the forcings in 1950, and way more than the forcing in, say, 1910. What am I missing? What caused the significant change in temperature in the first half of the 1900's?

By oconnellc (not verified) on 05 May 2007 #permalink

Valuethinker:You are correct, that was a bit of an exaggeration.... It's something like between 10-15 million vs 50 million in reality. I guess I should have said more than the population of Greece to be more exact. Of course, like me, not everyone that listens agrees totally and some won't at all. That's still a lot of potential advocates. (I don't know Boortz's, but he's syndicated on 179 stations).
And yes of course climate is more of a hard science, but once you get past specifics like what the temperature is as an average in ocean a or amount of co2 from volcano b or city c etc, and try and get them all together with every single instance on a global scale combined with cloud effects etc, it becomes less pure science and more like economics a bit. It was more meant to be an analogy than a comparison (although not the best analogy I suppose).

oconnellc: I wouldn't exactly consider this arguing. :) But I think that's what I'm saying, my eyes just don't match the effects well enough to the causes to give me any kind of black and white feeling, just a gray opinion. But as I said, we should be doing something about it regardless, and it certainly seems to match.

Graph, it's the GHCN - ERSST, and just remember to change the end month to December.... :)

Here: http://www.ncdc.noaa.gov/gcag/GCAGts?dat=BLEND&SYST=TS&TS=6

Chris: Can't argue with you there.

So, I went to the ncdc graph, and it is pretty handy. From 1910 to 1940, the trend was 0.12°C/decade Significance: 100.0% I'm not sure what they mean by "significance" in this context. For 1976 to 2006, the Trend: 0.17°C/decade Significance: 100.0%

So, the rate now is .05 decade higher than it was 100 years ago. I must be missing something. The rate now is ~33% higher than it was 100 years ago. And that graph of Forcings from RealClimate doesn't help much. The forcings are considerably higher now than they were 100 years ago. What is the difference? Why is the warming now due to Anthropogenic CO2, but 100 years ago it was natural variability? And why do we look at those blue bands and think that they can explain natural variability? Shouldn't the temperature during the period when we are most confident that temperature is not affected by human activities be inside those blue bands?

By oconnellc (not verified) on 07 May 2007 #permalink

I would suppose part of the answer to any of the questions is the data producing the graphs. Not everything uses the same set. Details are on various ncdc web pages or publications linked from them. Those pages and documents are the source of this information. I'm using GHCN-ERSST as an example, and this is what it looks like, if I'm summarizing it correctly.

Anomalies are analyzed monthly by the ERSST.v2 method, where the low-frequency anomaly from a grid (1Xº by 1Xº) over 15 years is removed (Current web, 15º) (2004 SST PDF mentioned in #222, 10º), and the residual high-frequency anomaly is fitted to a screened set of spatial-covariance modes. Then high- and low-frequency results are added.

GHCN is by 5º grids from monthly averages of the 2592 stations in the system having at least 25 years of data during the 1961-1990 base period. ERSST is 2º grid data from ICOADS (22 observed and derived variables) and averaged to a 5º grid to match the ones for land temps. Then both the data sets are merged into one, weighting land/sea depending on the land/sea ratio for that grid.

So what we're looking at is a monthly anomaly update of 72 longitude x 36 latitude 5º grids, and we're looking at them all at once as a whole for both land and sea. The fifty thousand foot view so to speak; a general idea of what's basically going on overall.

Things that might be factors. Before 2005 for the GHCN data, it wasn't the Anomaly but the First Difference methodology for the mean temperature grid (and in 2004, temporal interpolation with FD went from a 2 year to 10 year restriction on number of missing years allowed). So it seems before 2004/2005, anyone looking at the GHCN data was looking at something different than they are now. The sea temps have been available also in a 1º grid summary from ICOADS since 1960, so using that data instead of the 2º that ERSST uses might be a little different also. The "average global temperature" that anomalies are compared to is the base period of 1961-1990 (at least as of 1997; I do not know if they've changed). So we are really seemingly only comparing everything to that (or some other) 30 year period. That has a bearing on this data set compared to others, if they use a different period or length or data set or methodology. When you start mixing or comparing disciplines within climate science, it becomes more murky.

This is what makes it sometimes difficult to know what's going on; it depends on who's using what data and how the data was prepared. Seems like there's a lot of mix and matching going on, which makes it even more difficult to compare all the studies and reports.

The question of significance, it looks like longer periods give more significance. (The GHCN people suggest if looking at individual years or less, or comparing regions, that you don't use GHCN but rather individual station data.) No matter what areas I tried, 2, 5, 15 or 360º (85-100/35-50, 95-100/45-50, 98-100/48-50, -180-180/-90-90) a 15 year period of Jan-Dec was 97% significance but a 5 year period was 13%. Although it's possible another area might vary according to year and/or with the size of the grid. (The 2 5 and 10º grids happen to be various locations in China and Mongolia btw, randomly chosen numbers for lat/long)

One thing that does play into all this, besides knowing where the data is coming from (so if you're looking at something where it's different, you can know why) is confidence interval and margin of error. For the sea surface temps, that's a 95% confidence we're within a .1ºC average overall, for that base period. I could not locate the same information on land temps, but looking at the materials, and the nature of both the measurements and their complexity, I would imagine it's a higher margin. So my answer your other question would be that it's quite possible the .05º difference between .12 and .17 you're seeing is the margin of error, alone or in conjunction with some of the other factors I mentioned above.

I did find in the QC document on GHCN they link to http://www.ncdc.noaa.gov/oa/climate/ghcn-monthly/images/ghcn_temp_qc.pdf that CLIMAT and (the less reliable but still used afaik) GTS temps differ from each other by as much as .5ºC That's not to say the margin of error is anywhere near that of course, but also there are stations that only report data to the nearest half degree, transcription errors, broken equipment (missing data) etc.

By Robert S. (not verified) on 08 May 2007 #permalink

Whatevah - this discussion is as old as the bread old Norm throws to the geese in the park.

Society has moved on.

What's the best mixture of adaptation and mitigation is what people are talking about, and what'll it cost?

HTH,

D

Righteo, what is the best mixture of adaptation and mitigation and what will it cost.

Randomly:

How about .5% of GDP of each country for each? For the US that would be $120 billion a year total, Germany $23 billion, etc.

Or 80% adaptation and 20% mitigation, with a 10% increase in the money currently being spent?

How about a 50% increase in R&D for related endeavors?

What shall we do....

I fear it will take quite a bit of time to come up with rational numbers and a reasonable effort. Ah, politics.

By Robert S. (not verified) on 09 May 2007 #permalink

Dano, nice try, but it didn't really help much. I still don't understand how that plot of temperature forcings is supposed to explain anything about temperature trends in the last 150 years. I still don't understand why anyone would think that that blue band shows any understanding of temperature changes. I don't know why I have read many times that a symptom of AGW is nightime temperatures increasing faster than daytime temps, but the SPM says this is not happening. I don't know why people who keep describing the consensus don't refer to the IPPC chapter 6 discussion of the "divergence problem" and stating there is no consensus about "If true, this would imply a similar limit on the potential to reconstruct possible warm periods in earlier times at such sites".

Dano, society may have moved on, but it is just as likely that they have moved on to the discussion of how long Paris Hilton should be in jail. Your continued assertions that the intelligent among us are talking about other things really isn't helpful.

By oconnellc (not verified) on 09 May 2007 #permalink

Lambert: "The hypothesis tests that the IPCC refers to achieved levels of confidence greater than 95%". I have searched TL's source, the SFP

Instead, we find that "there is high confidence (i.e. 80%) that the rate of sea level rise increased from the 19th C to the 20th C". First, as there is no evidence on what the RATE of sea level rise was before 1900, how can the IPPC so "highly" confident that the RATE has increased since 1900? Second, "the total 20th C rise is [highly confidently] estimated to be 0.17 (0.12 to 0.22) m". When the range is 30% either way, the claimed level of confidence is close to meaningless. If your surgeon was highly confident that a course of aspirins would raise your life expectancy by 2 weeks, +- 30%, it could be time to change to another. However I will cite the IPCC to my Mebourne Cup bookie to get him to adjust my odds by 30% either way.

Logically speaking: You are right, I was merely trying to find TL's source in the SPM. His pretty figs at the beginning of this thread are all very fine, but the red and blue bands are clearly stated to be the outcomes of modelling using various assumptions about solar effects, volcanoes, and CO2. Where are the data inputs for these assumptions and statistical analysis thereof (preferably in Excel format complete with cointegration, ts, ps, etc)? Counting up and then averaging computer model simulations is NOT a valid test of an hypothesis.

Lambert: "The hypothesis tests that the IPCC refers to achieved levels of confidence greater than 95%". I have searched TL's source, the SFP

Instead, we find that "there is high confidence (i.e. 80%) that the rate of sea level rise increased from the 19th C to the 20th C". First, as there is no evidence on what the RATE of sea level rise was before 1900, how can the IPPC so "highly" confident that the RATE has increased since 1900? Second, "the total 20th C rise is [highly confidently] estimated to be 0.17 (0.12 to 0.22) m". When the range is 30% either way, the claimed level of confidence is close to meaningless. If your surgeon was highly confident that a course of aspirins would raise your life expectancy by 2 weeks, +- 30%, it could be time to change to another. However I will cite the IPCC to my Mebourne Cup bookie to get him to adjust my odds by 30% either way.

Logically speaking: You are right, I was merely trying to find TL's source in the SPM. His pretty figs at the beginning of this thread are all very fine, but the red and blue bands are clearly stated to be the outcomes of modelling using various assumptions about solar effects, volcanoes, and CO2. Where are the data inputs for these assumptions and statistical analysis thereof (preferably in Excel format complete with cointegration, ts, ps, etc)? Counting up and then averaging computer model simulations is NOT a valid test of an hypothesis.

Lambert: "The hypothesis tests that the IPCC refers to achieved levels of confidence greater than 95%". I have searched TL's source, the SFP

Instead, we find that "there is high confidence (i.e. 80%) that the rate of sea level rise increased from the 19th C to the 20th C". First, as there is no evidence on what the RATE of sea level rise was before 1900, how can the IPPC so "highly" confident that the RATE has increased since 1900? Second, "the total 20th C rise is [highly confidently] estimated to be 0.17 (0.12 to 0.22) m". When the range is 30% either way, the claimed level of confidence is close to meaningless. If your surgeon was highly confident that a course of aspirins would raise your life expectancy by 2 weeks, +- 30%, it could be time to change to another. However I will cite the IPCC to my Mebourne Cup bookie to get him to adjust my odds by 30% either way.

Logically speaking: You are right, I was merely trying to find TL's source in the SPM. His pretty figs at the beginning of this thread are all very fine, but the red and blue bands are clearly stated to be the outcomes of modelling using various assumptions about solar effects, volcanoes, and CO2. Where are the data inputs for these assumptions and statistical analysis thereof (preferably in Excel format complete with cointegration, ts, ps, etc)? Counting up and then averaging computer model simulations is NOT a valid test of an hypothesis.