A Few Things Ill Considered

Another way to look at it is to ask What if it is true? What if it is not true? and what are our options in either case...or more comfortably in the cases or scenarios we can spectulate on.

I like this approach.

Posted by: CityzenJane | October 21, 2008 3:18 PM

I have found "How to Talk to a Climate Sceptic" extremely helpful for dealing with all sorts of people who have reasonable-sounding objections to the anthropogenic global warming hypothesis.

Thanks for producing such a useful resource.

Posted by: Milan | October 22, 2008 7:38 AM

Hey Coby, it looks like Craig Loehle is also intrigued by the fact that proxy data diverges from instrument data in the the last couple of decades. He seems to come to much the same conclusion about this problem as I do. Only he says it so much better and he published it in a scientific paper.

A MATHEMATICAL ANALYSIS OF THE DIVERGENCE PROBLEM IN DENDROCLIMATOLOGY
Climatic Change
DOI 10.1007/s10584-008-9488-8

Craig Loehle, PhD
National Council for Air and Stream Improvement, Inc. (NCASI)

Abstract: Tree rings provide a primary data source for reconstructing past climates, particularly over the past 1000 years. However, divergence has been observed in twentieth century reconstructions. Divergence occurs when trees show a positive response to warming in the calibration period but a lesser or even negative response in recent decades. The mathematical implications of divergence for reconstructing climate are explored in this study. Divergence results either because of some unique environmental factor in recent decades, because trees reach an asymptotic maximum growth rate at some temperature, or because higher temperatures reduce tree growth. If trees show a nonlinear growth response, the result is to potentially truncate any historical temperatures higher than those in the calibration period, as well as to reduce the mean and range of reconstructed values compared to actual. This produces the divergence effect. This creates a cold bias in the reconstructed record and makes it impossible to make any statements about how warm recent decades are compared to historical periods. Some suggestions are made to overcome these problems.

Posted by: Tilo | October 25, 2008 6:49 PM

A sort of counterpoint to your "How to talk to a Climate Sceptic" is Joanne Nova's "The Skeptics' Handbook" . When you go to http://climatedebatedaily.com you find under the heading"Rising above the mudslinging" Joanne's arguments, for what they are worth, against the CO2 thesis. Can you please comment on these?

Posted by: Arie Brand | October 25, 2008 10:15 PM

Makron:
"It's not actually a greenhouse signature and it isn't exactly missing."

The only way that it's not missing is if you use windshear to measure temperature instead of using ballon and satellite measurements. This seems to be an absurd way of getting to a forgone conclusion.

"There's more wrong in this section than I probably have space for in just this comment."

Yes, there has been no rise in temperature for the last 11 years. Only Hansen's heavily "adjusted" record shows half the rise that the IPCC predicts. The rest show a small amount of cooling.

http://reallyrealclimate.blogspot.com/2008/06/11-year-temperature-anomoly.html

"The short answer is more."

I don't think that it takes any more. If the warmers cannot explain why there has been no warming for the last 11 years, during which we have had significant rise in CO2 - if they cannot explain where that .2C rise has gone in terms of elements of natural variation overriding the CO2 forcing, then the CO2 forcing numbers are wrong. We are now dealing with hindsight. All of the forcing elements can be measured and they can be used to explaing why there has been no warming. But there are no explanations for the failure to warm. Noise is not an answer. Noise is natural variation, and we are suppose to understand the effects of natural variation. I have put this question to Gavin Schmidt, and he ran away from it. He has no idea why we haven't warmed over the last 11 years. So if we don't know enough about natural variation to explain what has happened, how can we know enough to extract a climate sensitivity number?

"and that fits with about 3C warming per doubling of co2."

I'm not sure what you are claiming fits with the 3C per CO2 doubling, but I think that the point of the article is this.

If 3C were true (which I think it isn't) then to get the first 3C you would need to go from 280 PPM to 560 PPM. To get the second doubling you would need to go from 560 PPM to 1120 PPM. To get the third doubling you would need to go from 1120 PPM to 2240 PPM. So going to 2240 PPM would get you about 9C. This is serious. But of course we will probably run out of fossil fuels long before we even get that second doubling to 1120 PPM. So even if the 3C climate sensitivity were true, you would be hard pressed to ever get a total of 6C. But what if the climate sensitivity is closer to 1C, as some climate scientists predict. Then the move from 280 PPM to 1120 PPM would only get you 2C. No big deal. We have been there before. So far we have had .8C of temp rise for the industrial era. We have almost 40% of a doubling. On the logrithmic scale, this means that we should have half of the temperature effect of one CO2 doubling. This means that a doubling would get us about 1.6C. But the .8C that we already have was effected by coming out of an little ice age, a strengthening in solar activity, as well as PDO effects in the most recent years. So we can probably only attribute a portion of that .8C to CO2 increase. Emperically, this would indicate that the effect of a CO2 doubling is much less than 1.6C.

Posted by: Tilo | October 26, 2008 7:50 PM

By the way Coby, in light of this article, would you like to reconsider what was said by some scientists about the expected 2008 Arctic ice melt.

(CNN) -- The North Pole may be briefly ice-free by September as global warming melts away Arctic sea ice, according to scientists from the National Snow and Ice Data Center in Boulder, Colorado.

"We kind of have an informal betting pool going around in our center and that betting pool is 'does the North Pole melt out this summer?' and it may well," said the center's senior research scientist, Mark Serreze.

http://www.cnn.com/2008/WORLD/weather/06/27/north.pole.melting/index.html

Posted by: Tilo | October 26, 2008 8:25 PM

Arie - I think it would help the debate if you were clear about what issue you are aiming to argue for here ie. is it that in the title of this post?

The first paragraph you quote does not really have a point or make an argument of any kind, it is just an unordered list of assertions.

The second is a little less obviously sloppy, except where it says "The unusual warmth in 2007 is noteworthy..." which is in direct conflict with, erm, the first paragraph which says "For detecting climate change you should not look at any particular year, but instead examine the trends over a sufficiently long period of time."

This is not semantics, this lack of precision and desire to have it both ways is one of the fundamental problems here. Tilo in fact said before your post - "When it is to their benefit, they are very willing to use short term or single year events.".

Anyway, aside from that, even if one were to concede to you all the points made in those two paragraphs (which I most certainly do not), explain to me how they mean that human generated CO2 is the CAUSE of this upward warming trend?

And, while i'm here, this CO2 induced upward trend I keep hearing so much about is - well, what exactly? It does not include the pre-war period, as we all agree that only 20% or so of the human CO2 had been released then. It doesn't include the, er, drop from WW2 up to the mid 1970s. It doesn't include the levelling off of the last 10 years. So, it is the period from mid-to-late 1970s to 1998. Not even 30 years - the magic climate change number I keep having quoted to me.

Sorry, I just don't understand where this certainly comes from. Tilo is right - how can anyone be so utterly certain about a future rise if the recent slight fall in temperatures cannot be explained at all, even with the benefit of hindsight?

Posted by: paul | October 27, 2008 5:23 AM

For Paul:

“Arie - I think it would help the debate if you were clear about what issue you are aiming to argue for here ie. is it that in the title of this post?”

I thought I had made it clear that I was querying Tilo’s assertion that the climate has stopped warming over the last 11 years. As to the wider issue (the question whether human generated CO2 has been the cause of this upward warming trend) I thought that Coby defended that proposition pretty well. Long existing theory in physics would make you expect this effect of CO2 anyway, there are no other credible candidates for the warming trend and, equally, there are no other credible candidates for the increase in CO2 other than human activities. If you have difficulties with this form of argument (“argumentum per eliminationem”) you should take this up with Coby – not with me.

“The first paragraph you quote does not really have a point or make an argument of any kind, it is just an unordered list of assertions.”

The lack of order might be in the mind of the beholder. To me the statements there seemed to be in direct contradiction to what Tilo was claiming. Incidentally, Tilo claims that when he put the question re the (alleged) non-warming to Gavin Schmidt he “ran away from it”. I would be grateful to be told where I can find evidence for this.

“The second is a little less obviously sloppy, …”

I am glad you gave that red schoolmaster’s pencil some rest there. . .

“except where it says "The unusual warmth in 2007 is noteworthy..." which is in direct conflict with, erm, the first paragraph which says "For detecting climate change you should not look at any particular year, but instead examine the trends over a sufficiently long period of time."”

I don’t see the contradiction. It is not claimed that the record for 2007 establishes a trend. It could be that the authors found it noteworthy because it is in direct contradiction to what some people have been saying about the global temperature in recent years, including this particular year.

“This is not semantics, this lack of precision and desire to have it both ways is one of the fundamental problems here. Tilo in fact said before your post - "When it is to their benefit, they are very willing to use short term or single year events.".
Anyway, aside from that, even if one were to concede to you all the points made in those two paragraphs (which I most certainly do not), explain to me how they mean that human generated CO2 is the CAUSE of this upward warming trend?”

See above.

“And, while i'm here, this CO2 induced upward trend I keep hearing so much about is - well, what exactly? It does not include the pre-war period, as we all agree that only 20% or so of the human CO2 had been released then. It doesn't include the, er, drop from WW2 up to the mid 1970s. It doesn't include the levelling off of the last 10 years. So, it is the period from mid-to-late 1970s to 1998. Not even 30 years - the magic climate change number I keep having quoted to me.”

That depends on the graph you are looking at. When I can give credence to the one to be found at http://www.realclimate.org/index.php/archives/2008/05/what-the-ipcc-models-really-say/langswitch_lang/sw#more-564 it looks as if the temperatureline between 1950 and the early sixties was fairly flat and that after that it went unmistakably upward.

“Sorry, I just don't understand where this certainly comes from. Tilo is right - how can anyone be so utterly certain about a future rise if the recent slight fall in temperatures cannot be explained at all, even with the benefit of hindsight? “

Who speaks about “certainty”? Once the role of CO2 in warming is acknowledged (even if it is only responsible for 1/3 of the temperature rise as some claim) there is a strong expectation that temperatures will rise because one can be pretty sure that human activities over the next few decades will keep increasing the level of CO2 in the atmosphere. But many other factors can come in between. We are merely talking, it seems to me, about probabilities here but probabilities strong enough to inspire political action. In the country where I originally come from (Holland), for instance, they just cannot afford to wait for “certainty”, for obvious reasons.

Posted by: Arie Brand | October 27, 2008 5:31 PM

�Quoting someone else who thinks what you think is not going to persuade me�.

The World Meteorological Organisation and NASA are not just �someone else�. What do you want me to do? Provide you with the data of that weather station in my own backyard? I am not a climatologist (neither are you I think) but having worked for many years in academe in some other discipline has given me a fairly good nose for the difference between serious stuff and bs.

�So what is this trend you speak of? You attack my contention that the global temperature dropped mid-century. ..�

I did no such thing. Look again.I am familiar with the explanation that round about that time the effect of CO2 was offset by that of manmade aerosols.

As to the trend: Tamino has beautifully plotted it in a post of 31st August last year. See: http://tamino.wordpress.com/2007/08/ . To me this is serious stuff.If you want to attack it you have to either take issue with his data (taken from NASA GISS and HadCRU)or the way he has plotted them or both.

� � in which case what probabilities are you speaking of?�

Here again I must rely on what serious and obviously knowledgeable people outside my own discipline tell me. James Annan (of �James Empty Blog� ) is for me such a person. He came up with six posts on �probability� in this matter. The last one has the address: http://julesandjames.blogspot.com/2006/02/probability-prediction-and_18.html I hope it works.

I want to quote one passage from it because it has something to do with the trend:

�When the models fail to reproduce the data, of course it calls their validity into question - at least, it does if the data are reliable. A striking example of models teaching us about reality is in the recent resolution of the tropospheric data/model incompatibility in favour of the models (OK, I'm over-egging things a little perhaps). Looking back over the longer scale, we have Hansen's famous forecast from 1988, which has proved to be spot on over the subsequent 17 years (this was written midway 2006. A.B.). In fact, the simplicity of the physics means that one thing we really can forecast quite confidently is a continued global warming in coming decades: the IPCC TAR said it was likely to continue at 0.1-0.2C/decade for several decades to come, and although this perhaps could be nudged marginally higher (we are getting close to the 0.2 limit), it won't be far wrong.�

Mind that phrase �the simplicity of the physics�. Too simple for you?

Whatever is the case this is my last post to you.

http://julesandjames.blogspot.com/2006/02/probability-prediction-and_18.html

Posted by: Arie Brand | October 28, 2008 2:47 PM

Arie:

My apologies for taking so long to respond. I've been a little pressed for time lately. I will try to answer you questions, but it may take more than one post.

Okay, first you want to know why I believe that we have had no warming for the last 11 years.

Here is my plot of the data.

http://reallyrealclimate.blogspot.com/2008/10/updated-11-year-global-temp-anomoly.html

I've updated it to the most current month. Double click to see a larger image. Now you may believe that I have manipulated this data for my own purposes, but I can reassure you fairly easily. This data is monthly data from Oct 97 to Sept 08 - or 11 years. There is nothing magical about the chart. I simply went to the RSS, UAH, HadCrut, and GISS sites, got their raw data, put it in Excel, told Excel to plot it, and told Excel to run a linear regression line through all of the data sets. If you want to verify this by reporducing your own chart, let me know and I will give you a few more specifics. It's easy.

As you can see, three of the data sets trend slightly down, and only James Hansen's GISS data trends up. According to the IPCC, we should get about .22C of warming over an 11 year period. Only Hansen has any warming, and his is still only half of the IPCC projected warming. The other three differ from the IPCC projection by more than .22C.

Now, my statement that the 11 year temp trend is flat basically throws out Hansen's data set. I consider his data as divergent and as an outlier. Also, given Hansen's heavy adjustment of the data, the inexplicability of some of his adjustments, and his clearly emotional connection to the warming cause, I'm simply not ready to trust his data set. By the way, it's interesting to note that in the 80s and 90s, while global temp was going up, Hansen's data did not diverge from the others. All that said, even if you averaged Hansen's data in with the other three, you would still be close to flat.

Now as you would expect, the warmers have tried to explain what you are looking at; and the explanation is basically this - a strong El Nino at the front of the period raises the trend line starting point up, and a La Nina at the end of the period pulls the end of the trend line down. Therefore, those two events yield an unrepresentative trend line.

But unfortunately their explanation will not hold water. The period that we are looking at actually contained 7 ENSO events. There were 4 El Nino's and 3 La Nina's. Here is the NOAA chart where you can look that up.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

I tried to hack out a method for myself to determine what effect these seven ENSO events had. The result of my effort is here.

http://reallyrealclimate.blogspot.com/2008/05/ten-year-hadcrut3-enso-effects.html

Using my method I ended up with a conclusion that after the ENSO events had been accounted for, there would still be a tiny negative bias to the trend line. But basically I considered it still to be flat.

A little later, Gavin Schmidt, employed a paper that had been published by one of his fellow scientists, and that contained a formula for removing ENSO effects, to produce his own ENSO corrected data set. Gavin did not publish a graph of his results, his simply told the people at realclimate that the corrected trend still showed warming. Since Gavin gave a link to the data set, I decided to get that data set, and plot it against the uncorrected data. By the way, the correction that he made was to the HadCrut3 data. Here is the result of Gavin's data versus the uncorrected data.

http://reallyrealclimate.blogspot.com/2008/07/gavin-schmidt-enso-adjustment-for.html

As you can see, there is a positive bias to the adjusted data, but it is so small that I will still call the trend flat. Note, Gavin only produced 10 years of data, so that is what I used.

The other argument that swirls around this plot concerns the warmers assertion that 30 years of data are required to show a trend. Since they have a sweet spot that consists of 30 years, they particularly like that number. But I would like to note 3 things in regards to that. First, Schmidt and Hansen together have published a paper and drawn conclusions that were based exclusively on 10 years of ocean warming data. Second, the variability of the data that explains the need for 30 years of the stuff is suppose to be noise. Note that all of the data sets that I presented zig and zag together. Even if the data gathering method is completely independent. And lastly, trends are generally defined by a linear regression trend line. This line is, of course, allways a straight line. So let's take an extreme example to make my point. Let's say that you have 30 years of data. Let's say that for the first two years of that data it got warmer. Then let's say that for the last 28 years, the data was absolutley flat - no warming at all. Then if you draw a trend line through all 30 years, you will get a warming trend line. So by declaring that you have had 30 years of warming, you will have completely missed the point that there wasn't any for 28 years.

Okay, that's a start. Right now my job calls, so I'll have to continue this later. Hopefully you understand why I am saying that there has been no warming for the last 11 years.

Posted by: Tilo | October 29, 2008 8:48 AM

“Quoting someone else who thinks what you think is not going to persuade me”.

The World Meteorological Organisation and NASA are not just “someone else”. What do you want me to do? Provide you with the data of that weather station in my own backyard? I am not a climatologist (neither are you I think) but having worked for many years in academe in some other discipline has given me a fairly good nose for the difference between serious stuff and bs.

“So what is this trend you speak of? You attack my contention that the global temperature dropped mid-century. ..”

I did no such thing. Look again. As to the trend: Tamino has beautifully plotted it in a post of 31st August last year. See: http://tamino.wordpress.com/2007/08/ . To me this is serious stuff.

“ … in which case what probabilities are you speaking of?”

Here again I must rely on what serious and obviously knowledgeable people outside my own discipline tell me. James Annan (of “James Empty Blog” ) is for me such a person. He came up with six posts on “probability” in this matter. The last one has the address: http://julesandjames.blogspot.com/2006/02/probability-prediction-and_18.html I hope it works.

I want to quote one passage from it because it has something to do with the trend:

“When the models fail to reproduce the data, of course it calls their validity into question - at least, it does if the data are reliable. A striking example of models teaching us about reality is in the recent resolution of the tropospheric data/model incompatibility in favour of the models (OK, I'm over-egging things a little perhaps). Looking back over the longer scale, we have Hansen's famous forecast from 1988, which has proved to be spot on over the subsequent 17 years. In fact, the simplicity of the physics means that one thing we really can forecast quite confidently is a continued global warming in coming decades: the IPCC TAR said it was likely to continue at 0.1-0.2C/decade for several decades to come, and although this perhaps could be nudged marginally higher (we are getting close to the 0.2 limit), it won't be far wrong.”

Mind that phrase “the simplicity of the physics”. Too simple for you?

And this is my last post to you.

Posted by: Arie Brand | October 29, 2008 1:17 PM

Arie:
"I want to quote one passage from it because it has something to do with the trend:"

James Annan:
"Looking back over the longer scale, we have Hansen's famous forecast from 1988, which has proved to be spot on over the subsequent 17 years."

Unfortunately, James was wrong and Hansen's forcast isn't so wonderful after all. Hansen presented three scenarios for future climate change in 1988. In his most optimistic scenario the level of CO2 would stop rising around the year 2000. As it turns out, CO2 has been pouring into the atmosphere ever since and the level has risen significantly since 2000. And yet the global temperature is currently well below what Hansen predicted we would have if we stopped adding CO2 in 2000. And his business as usual scenario - which is in fact what happened - is hugely out of bed. If you look further through Annan's blog, you will see that he is no longer arguing in 2008 that Hansen's prediction is "spot on", but rather he is trying to show that Hansen's prediction has not been falsified if you use large enough error bands. So now he wants the three scenarios plus the error bands for each of those scenarios.

A good discussion on Hansen's 1988 prediction can be found here:

http://www.climateaudit.org/?p=2602

Lucia Liljgren over at The Blackboard likes to work with statistics, and she has done several posts showing that many of the model predictions that have been used by the IPCC have been falsified. Here is her site.

http://rankexploits.com/musings/

I haven't bookmaked any of the relevant articles, so you will have to rummage about.

Posted by: Tilo | October 29, 2008 2:41 PM

Arie:
I wanted to answer a few of the questions that I left unsanswered in my previous post. You can find the discussion with Gavin Schmidt here:

http://www.realclimate.org/index.php/page/2/index.php?p=577#comment-92337

My first post is at 128. Follow up posts, including responses are scattered through the rest of the thread.

Note: my essential question that was never answered was this:

"So then comes the next question. If the decadal warming trend caused by CO2 is .2C, and if ENSO is now adjusted for, then where is the other .187 C of temperature rise? If we are going to attribute the flat trend to elements of natural variation, and if we have already accounted for ENSO, then to what elements of natural variation can we attribute the flat trend for the last decade?"

You will see that Gavin addresses my entries on several occasions. But it's always an attempt to steer the conversation in another direction. He never actually tackles my question. Finally, Tamino does one of his pieces of statistical sophistry, claiming, basically, that you can't trust your lying eyes and that even if the trend is flat it is still "consisten with" AGW predictions. I answered Tamino, giving my objections to his reasoning, but as Realclimate always does when they are in a fix, they didn't put up my post, thereby giving their view the last word.

Concerning a bet with James Annan, I actually offered James a bet a few month ago. I offered to bet him 10,000 dollars on the IPCC temperature projections. So if the temperature rose .2C or more per decade between 2000 and 2030 I would pay him 10,000. If not, he would pay me 10,000. If the IPCC is right, this would be a 50/50 bet for both of us. My main objective was to see if a climate scientist would actually have the integrity to stand behind their believes. It was not to make money, and with a 50/50 bet, Annan might not make it either. Of course Annan wouldn't take the bet. In fact, he wouldn't even make a counter offer, claiming that it was not his number. I would probably have accepted an ajustment that gave him a minor edge, but there was no offer. Instead, Annan said that he was working on his own climate sensitivity number. I told him that I would wait to see it, and that I would probably make him a bet at that time. So far James hasn't produced a new number. Or at least he hasn't produced one that he would be willing to publish, given funding concerns.

Rummage about James' site about 2 or 3 month ago and you should find the offer for a bet from me.

Concerning your other quotes that I haven't responed to yet:

"the global climate on an average is warming despite the temporary cooling brought about by La Niña."

I think that I have already shown that the leveling of temperatures for the past 11 years is not at all related to a singe La Nina.

“The year 2007 tied for second warmest in the period of instrumental data, behind the record warmth of 2005, in the Goddard Institute for Space Studies (GISS) analysis."

This is a perfect example of the warmers being willing to exploit single year events when it suits their purpose - as is the meltoff of 2007. Beyond that, the "second warmest" is only applicable to the GISS record. The HadCrut3 record, the UAH record, and the RSS record don't have it anywhere near that position. It was real more around 7th or 8th. Hansen feels that he needs to fuel the AGW fire by constantly feeding it alarmist reports. In any case, it is irrelevant. Once you reach the top of the mountain and start down, for your first few steps you will still be able to say that you are still near the top of the mountain. But that doesn't mean that you are still climbing.

Posted by: Tilo | October 30, 2008 9:44 AM

Tilo, I can't find your bet offer on James Annan's blog.Can't you give a more precise indication? I would like to see his side of the story.

Also, why did you try to put your objections against Tamino's piece of 'statistical sophistry' on Realclimate (where you claim that your post was suppressed). Why didn't you put it on Tamino's blog?

Also, I still would like a more precise indication of the places on Realclimate where you claim that Gavin Schmidt evaded your question.

Just checking.

Posted by: Arie Brand | November 1, 2008 4:08 AM

Just because the amount of C02 in the atmosphere has risen doesn't mean it is caused by humans. Humans only emmit 3% of C02 emissions, the Earth the other 97%. As the Earth warms, oceans emmit more Carbon Dioxide, and therefore the amount increases.

It should be said that, "Temperature is the cause of high C02".

Posted by: Nathan | November 3, 2008 3:40 PM

So Arie - it seems you're less interested in discussion than in simply telling people what is and isn't true. Or are you going to answer Tilo? It took me no noticable time to track the links he provided. The question Tilo puts seems perfectly reasonable to me - I've looked for months now and cannot find an answer to that question anywhere. If you have one, or an answer as to why it is not reasonable, I'm all ears.

This site would be a lot more useful - and it is useful, not least because Coby does at least allow the comments up regardless ie. not moderate those that disagree, like one well-known website I could mention - if you were interested in answering questions put to you and not evading them.

Posted by: paul | November 7, 2008 5:12 AM

Tilo never "came up with" anything. He asked you what effect accounts for the 0.18 degree discrepancy. It appears you don't know.

He asked Gavin Schmidt too. The response was:

Response: This is nonsense. The idea that ENSO is the only kind of intrinsic variability is silly. Look out of your window - and see planetary waves (of various wavenumber), the Madden-Julien oscillations, the NAO, the PDO, the PNA, the SAM, COWL, baroclinic instability, African waves, Antarctic dipoles etc etc. There is no shortage of variability in short term records. What would meteorologists have to talk about otherwise? - gavin

So he states that there is piles of variability in the short term records – he has named 11 possible sources of some or all of this 0.187 degrees. He has no idea exactly which ones were responsible though (or he would have said).

This statement is just jump-out-of-the-page ludicrous to me – it would make more sense as a response from a climate change skeptic. Who is to say some other unnamed combination of this laundry list of effects was not responsible for the 1975-1995 rise? What would be the answer to this? What COULD be the answer to this? Maybe, if you pick a 30 year trend, all these short-term effects cancel out to 0 and what is left is CO2 forcings? Does anyone have an answer to this?

The point is, you can’t say that you are sure that effect XYZ of these 11 was not responsible for the 1975-1995 rise while at the same time say you don’t know where the missing 0.18 degrees is, or certainly not without some exceptional reason. Ok, one period is 10 years and one is 20 – but these are conservative. Maybe one is only 18 and the latter more like 13 now. Either way, does anyone think the difference between the 10 and 20 years is the answer here?

To repeat - Who is to say some other unnamed combination of this laundry list of effects was not responsible for the 1975-1995 rise?

Posted by: paul | November 12, 2008 8:43 AM

Whoa. Who exactly was saying how complicated it is? I was going on what Gavin Schmidt said - I quoted exactly what he said. He basically said that there are lots of things the 6-8-10-12 whatever year stasis could be due to, it is just too short a time to be able to say.

But things suddenly get much simpler when you get to 20 years it appears. None of these effects are worth considering, the only thing it could possibly be is CO2. This is your view, is it not?

I'm not denying that the stats are more favourable for the 20 year rise, because they clearly are. But "more favourable than some alternative scenario" is not "true".

And on the basis of your argument ie. it's in the stats, if there was 20 years of stasis, you'd chuck out AGW theory. And so then you should be getting gradually less sure of your theory each year of stasis? Can you confirm this, that you are less sure about it than you were a year ago?

Also, you have consistently said that 30 years is the magic number for climate changes. Yet you just referred to the 20 year rise as a trend. Is a trend something that indicates a fundamental shift in climate that rises beyond short term variation? How long does it have to be? if you insist on using this word, can you please state in clear english what exactly a trend is?

Posted by: paul | November 12, 2008 3:31 PM

The historical data in IPCC quoted by everyone else are not explained. The issue is using engineering stochastic models to make 100 year projections IIASA, Merge Markal, Targets IMage Energy Regional simulation model: TIMER - MNP integrated assessment model; AIM; ASF; Message; Minicam; Maria; with versions having different functionality to address different characteristics of different scenarios. Arrhenius was wrong... he used the wrong spectral data in his analysis of atmospheric CO2; although the basic conclusions may hold the extent estimated is wrong. This talking is good, if there were not debate there would not be progress in understanding.

Posted by: brianwolbley | June 25, 2009 5:46 PM

brianwobley -

The talk about twenty year period with overall increase and writeoff of six year period of stasis as being noise sounds like selection bias.

There's no selection bias going on. Short periods of "stasis" are nothing unexpected or even new, as long as you cherry-pick the right dates.
See: 1977 - 1985 or 1981 - 1989
http://www.skepticalscience.com/Is-the-climate-warming-or-cooling.html

That's why you need a long period to make an coherent statement about climate. Over the short term, you are discussing weather effects over a multi-year period, NOT climate.
Read this for a more comprehensive, quantitative look this than my meager posting: http://moregrumbinescience.blogspot.com/2009/01/results-on-deciding-trends.html

So, since we're being intellectually honest and having a good open debate, I'm glad I could help point you in a direction for deeper understanding of the science.

Posted by: Adam | June 26, 2009 7:07 AM

My comments at http://scienceblogs.com/illconsidered/2009/06/from_a_failed_growth_economy_t.php went unanswered so I will repeat my questions here.

I pointed out that the Global Temperature trend, (taken from NOAA), from 1880 to 2007 revealed an increasing temperature trend of 0.05C per decade. If Global temperatures were to rise by 3C as predicted by IPCC when CO2 levels reach 560 ppm, estimated in 83 years from now, the temperature rise should be of the order of 0.362 per decade, a 724% increase.

To this Coby said “Why in the world would you start with 1880?� and "The rise is predicted to accelerate, and observed to be accelerating."

Posted by: Richard | June 26, 2009 2:14 PM

The article you referred me to says the oceans dampens the temperature change on land and lowers the global average trend. This maybe so but it doesn’t explain how an exactly similar warming trend to one that IPCC says is natural, can be distinguished from it and claimed to be Anthropogenic? How can the IPCC, on the face of this evidence, say that most of the observed increase in global average temperatures since the mid-20th century is VERY LIKELY due to the observed increase in anthropogenic GHG concentrations?

Also the article you refer me to says that CO2 is not the only factor effecting the global temperature Global Dimming is counteracting greenhouse gas warming. This again begs the same question as above.

Also if Global Dimming or WHATEVER is counteracting CO2 then doesn’t it look like that there is a negative feedback for the CO2, cancelling out its effect, and not a positive one enhancing it as modelled by the IPCC?

And how does this reconcile with your statement “The rise is predicted to accelerate, and observed to be accelerating.�?

Posted by: Richard | June 26, 2009 2:21 PM

Answer: If that be so how do you classify the last centuries' "Global Warming" as global warming? The "Global Temperatures" are again not reflected in the Antartic temperatures which show a very slight downward trend with not the variation of HADcrut or NOAA temperatures.

Adam wrote "..that's the point I was making ..In our relatively recent history, we've had a global climate that is very amenable to human civilization. Anything out of this narrow band would be bad news for us"

I replied "IF that AGW hypothesis you believe in is true, we are unlikely to move out of that "narrow band" of temperatures that is very amenable to civilisation. Because thus sayeth IPCC: if CO2 levels are doubled from pre-industrial levels ie increase from 280 ppm to 560 ppm our temperatures will rise by (most likely) 3 C which is well within the "narrow band" of temperatures we have had in our "relatively recent history" (the last 10,000 years). During the Holocene Optimum it stayed about that or more for centuries and even thousands of years."

Coby said - This is false (do you have any reference to support it?). Please see this article.

Answer - I have the GISP2 ice-core data before me, which clearly shows it. You can obtain the data and plot it yourself.

The article you refer me to is based on another article whose authors are Dr. Keith R. Briffa, Dr. Phil D. Jones, Dr. Michael E. Mann, and Dr. Henry N. Pollack. They all contributed heavily to the IPCC report which produced the "Hockey Stick" as the Smoking Gun of Anthropogenic Warming and obliterated the Medieval Warm Period and Little Ice Age in one stroke. Forgive me if I am a little sceptical about it.

This article also says "As an aside, it is worth noting that even if this time period had been as warm or warmer, it would do nothing to undermine the theories and data that indicate today's warming is rapid and anthropogenic."

I am sorry but that is not true. That is why you deniers (deniers because you deny science and data and evidence) fight tooth and nail to dispute and deny any evidence to the contrary. Because if this were so then there is no reason to assume that the slight warming of the last century is anything other than natural.

Posted by: Richard | June 26, 2009 2:53 PM

Coby at #14 "The Antarctic sea ice trend is negligible."

I dont know what you mean by negligible. Here is the data from 1979 the year that satellite records started from the National Snow and Ice Data Centre:
1. Jan 79 to Jan 2009 - increase of 2.6% per decade
2. Feb 79 to Feb 2009 - increase of 2.8% per decade
3. March 79 to March 2009 - increase of 4.7% per decade
4. April 79 to April 2009 - increase of 3% per decade
5. May 79 to May 2009 - increase of 2.1% per decade

The Northern sea ice is trending down between 3.1 to 2.1% per decade but for all the months its been going up (not trending I know) but going up, for all the months since 2006

Posted by: Richard | June 26, 2009 3:43 PM

No anthropogenic signature can be seen in the evidence.

OK, enough of poor richard. Denialists exist to waste time, nothing more.

Posted by: dhogaza | June 26, 2009 4:04 PM

Ok Coby I will address your complete concern - the one about CO2 forcing and the inappropriateness or otherwise of taking certain trends, end points etc sometime later today as I have all the arguments and data. Just need to put it in a clear organised manner.

I will address the issue of past temperatures, The Holocene Optimum and the Medieval Warm period and their significance later. In the meantime I apologise for making one incorrect statement. The GISP2 records dont show temperatures above 3C from today for the Holocene. But they do show temperatures 1C warmer for much of the time. 1.5C warmer for a significant amount of the time and even 2C warmer for centuries. The mistake arose because I plotted the Vostok and GISP2 curves together and estimated the height of the GISP2 curve from there. I now have a accurate picture with the separate GISP2 curves magnified over shorter time periods.

Posted by: Richard | June 27, 2009 1:40 PM

Now what are these two instances?

First lets discuss "What is evidence" Evidence is an observation that proves or suggests that human emissions of CO2 are the main cause of the recent GW. Evidence includes the following:
a, Who made the observations?
b, When were they made?
c, What did they observe (in general terms, i dont hace to see the raw data)
d, How do the observations support the idea that rising CO2 levels are the main cause of the recent GW?

Therefore the following do not constitute as evidence:
Polar bears
glaciers
arctic melt
storms
droughts
fires
malaria
rising sea levels
Ocean cooling
Ocean warming

Although each of these issues may say something about whether or not GW is or was occuring none of them say anything about the causes of GW.

The two instances i spoke of are (1)that CO2 does not drive/control the temperature as per the IPCC theory and (2) all the models predict a hot spot to appear 10 K above the tropics due to increases in WV. This hot spot does not exist.

Therefore the two tests that we can construct to test the theory both show the AGW theory to be false.

In an effort to cut down on posts containing only name calling and insults here are the reasons why the theory fails the two above mentioned tests.

The geological record dating back over 150 thousand years shows that CO2 LAGS temp by about 800 years, so how is it that the AGW theory says that an increase in CO2 levels will cause temps to increase? Secondly the geological record dating back even further (millions of years) shows no correlation at all. If the theory is correct shouldn't we see a correlation on all time scales? Clearly larger forces are at play.

The second is the missing heat signiture (hot spo, the IPCC models predict a heat signiture to appear 10K above the tropics (due to increased WV)however 20 years of searching 79-99 by radio sonde equipment with an accuracy 0.1C have not been able to find it.

Now before you lot go running off at the mouth, below is a link to the IPCC AR4

ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch09.pdf

I would like to direct your attention to page 675, graphs a through e show the heat signitures for solar, volcano etc and graph F shows the heat signiture of all these combined that should be present in the atmosphere, this heat signiture was predicted by a computer model of course.

This missing hot spot has two implications:
a, Proves the IPCC climate theory to be false
b, Undermines the theory that CO2 causes AGW

The usual practice when observations and theory disagree is that the theory yields to the observations. However in his case the IPCC (in true IPCC form) choose to attack the observations in an effort to keep the theory alive.

Santers (IPCC employee) objection was based on the simple theory that despite launching many, many RS balloons over a 20 year period we have simply missed the hot spot, which means it could be there its just that we cant find it and measure it, so we simply ignore (read change) the data.

publicaffairs.llnl.gov/news/news_releases/2008/NR-08-10-05-article.pdf

Next we have Sherwood (IPCC employee) who states we should simply ignore the temp data like Santer and instead use the wind shear data to measure the hot spot.

lubos.motl.googlepages.com/sherwood-allen-ngeo-2008.pdf

In summary, It is important to note that the IPCC scientists never claimed to have found the hotspot,
only that we might have missed it. This is an important distinction. They wrote several
densely worded papers that suggested, to a casual reader, that the hotspot had indeed
been found. But on careful scrutiny those papers always stop just short of claiming to
have found the hotspot.

Posted by: crakar14 | June 28, 2009 9:39 PM

crakar, I think the post you lost is here:
http://scienceblogs.com/illconsidered/2009/06/revisiting_co2_lags_not_leads.php#comment-1733949

I had replied to it there.

Posted by: pough | June 29, 2009 10:44 AM

The Earth has been warming (slightly) over the last 100 years - Correct
CO2 has been increasing - Correct
Human activity contributes to some of this CO2 increase - Correct
CO2 is a greenhouse gas - Correct
This increased CO2 is causing the Earth to warm - Wrong - or at least absolutely no evidence of it. The warming is well within the bounds of natural warming even within the last 100 years. See my post # 49.

IPCC - “Most of the observed increase in global average temperatures since the mid-20th century is VERY LIKELY due to the observed increase in anthropogenic GHG concentrations.� Before that according to IPCC the temperature changes were natural.

From the UK Hadley data - the Global Average Temperature graph from 1880 to 2008 show two major rises rises one from 1911 to 1944 and the other from 1976 to 2008. (From 1880 to 1911 and 1944 to 1976 the temperature goes up and down with an overall fall).

The warming trend from 1911 to 1944 comes to 0.161 per decade and that from 1976 to 2008 comes to 0.168 per decade, almost the same. The previous trend the IPCC acknowledges is natural how then can it be said that an exactly similar trend is Anthropogenic?

AGW alarmists will fall back on "thousands of scientists agree this is so". Maybe they do maybe some dont. But consensus by a thousand scientists or dozens of "peer reviewed" papers by a AGW clich who peer review each others papers CANNOT TRUMP ACTUAL OBSERVATION.

If the predictions or the underlying basic assumption/s are shown to be wrong then the hypothesis has to be rejected.

All 23 models of the IPCC have one common assumption - there is a positive feedback mechanism to the CO2. If there is a negative feedback then the CO2 influence will be much reduced or even negigible such that it cannot be seen in the background of natural warming and cooling. The evidence from actual observations point to exactly this.

Posted by: Richard | June 30, 2009 4:14 AM

Science does not work by "knowing" something shared by a few who "live in a reality-based world". They discuss and work on the evidence, which I have presented above and which is not addressed.

Coby you have said you would address one thing at a time address this. And also acknowledge my post # 54, which I reproduce below: Look up the facts and acknowledge it.

Coby at #14 "The Antarctic sea ice trend is negligible."

I dont know what you mean by negligible. Here is the data from 1979 the year that satellite records started from the National Snow and Ice Data Centre:
1. Jan 79 to Jan 2009 - increase of 2.6% per decade
2. Feb 79 to Feb 2009 - increase of 2.8% per decade
3. March 79 to March 2009 - increase of 4.7% per decade
4. April 79 to April 2009 - increase of 3% per decade
5. May 79 to May 2009 - increase of 2.1% per decade

The Northern sea ice is trending down between 3.1 to 2.1% per decade but for all the months its been going up (not trending I know) but going up, for all the months since 2006

Posted by: Richard | June 30, 2009 11:55 AM

Congratulations, Richard, on your posts here and on other threads in this forum. They are deeply impressive. It is a real pleasure to read contributions that demonstrate such analytical powers and lucidity.

Posted by: Snowman | July 3, 2009 12:35 PM

Richard -

However this year in May the ice extent was 13.4 million sq km compared to 14.1 million sq km in May 1979. This is average ice cover with good concentration, so well on its way for a normal or above normal extent this August, adding to a growing body of evidence that the Earth has started cooling contrary to the predictions of the IPCC.

When you finally understand what is wrong with this reasoning, you will understand why no one (other than denialist trolls) takes your argument seriously.

Once more, for the slow:
A single month means very little, we are interested in the long-term trend.
Comparing May 1979 to May 2009 is not particularly relevant.
The extent was higher than 1979 in 1985, and very near 1979 in 1998 and 1999. In neither instance did the sea ice "recover", as the long-term trend remains downward.
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/May/N_05_plot.png

So far, every piece of 'evidence of cooling' you've mentioned has been complete bollocks, and this one is no different. You can cherry-pick individual data-points all you want to 'prove' your preconceptions, but all that does is make you look like a ninny.

Posted by: Adam | July 4, 2009 7:24 AM

Richard what is behind the logic in your comment "this year in May the ice extent was 13.4 million sq km compared to 14.1 million sq km in May 1979. This is average ice cover with good concentration, so well on its way for a normal or above normal extent this August"?

Surely if there is less ice in May than average it would suggest that there is every likelihood of there being less ice in August, not more?

Please explain your reasoning behind this comment.

Posted by: Ian Forrester | July 4, 2009 7:57 AM

Adam

Some of us are having difficulty in understanding why you accuse Richard of looking at only a single month. He makes the comparison on a month by month basis, up to the most recent available data (May).

You may have other, counter arguments, but in In what sense is Richard's case irrelevant?

Posted by: Snowman | July 4, 2009 8:02 AM

Coby,

The trend of Arctic Sea Ice for the month of May from 1979 to 2009 is -2.5%/decade. Sept is the lowest ice extent month and the trend for September up to 2008 is -11.1%/ decade. For Sept this year we will just have to wait and see. It makes sense to look at all the months not just the lowest ice extent.

You did say the trends for the Antarctic were negligible. Thats from the IPCC, but they are not. They are positive for all the months. I have given you the figures for all the months this year.
Jan 79 to Jan 2009 +2.6%/ decade
Feb 79 to Feb 2009 +2.8%/ decade
March 79 to March 2009 +4.7% per decade
April 79 to April 2009 +3% per decade
May 79 to May 2009 +2.1% per decade

If March is the lowest Ice extent in the Antartic thats trending up at 4.7%/decade

Posted by: Richard | July 4, 2009 3:56 PM

Actually the month-by-month comparisons are likely useful for computing another trend seen in the Arctic, the decreasing percentage of multi-year ice. This implies a decrease in *volume* much greater than the decrease in *extent* seen since 1979.

Posted by: dhogaza | July 5, 2009 6:19 AM

Ian Forrester, Adam,
"Compared to previous Mays, ice extent in May 2009 is about average." Source The National Snow and Ice Data Center
http://nsidc.org/arcticseaicenews/

Posted by: Richard | July 5, 2009 4:35 PM

Ian Forrester firstly know the difference between a denier and a sceptic. A denier is someone who refuses to accept reality when confronted with unassailable fact, which is what you are, a sceptic is one who questions a dubious assertion or assertions, which is what I am.

The assertions made by the warmers are: there is DANGEROUS global warming happening due to anthropogenic emmissions of greenhouse gasses chiefly CO2. The ice caps will melt, sea levels will rise catastrophically, hurricanes and cyclones will increase in intensity, there will be widespread droughts, and deaths due to heat waves. There is scant evidence for all this - therefore I'm a sceptic.

Regarding Arctic sea ice its a non-issue. If it disappears in summer it will make not an iota of difference to the sea levels. There is evidence that ice is actually accumulating on Greenland and certainly on Antartica. While you focus your razor sharp attention to the sea ice in the Arctic, which has lost 1.9 million sq Kms in June compared to May, you ignore the fact that that the Antarctic has gained 3 million sq Kms over the same period.

What I pointed out originally was, and let me bring back your attention to this,: Coby said #14 "The Antarctic sea ice trend is negligible." Well I have pointed out it is not.

Posted by: Richard | July 5, 2009 8:44 PM

Snowman -

There's nothing wrong with calling a spade a spade.

Posted by: Adam | July 6, 2009 4:42 AM

...instead of providing sensible rebuttals, he resorts to name calling.

What I find much more psychologically interesting is the people who read a comment with both name calling and sensible rebuttals, yet manage only to recall the name calling. Are you under the impression that other people haven't got the ability to scroll up a little and read the comments for themselves, or did you simply stop reading after the first sentence and really believe there was nothing more than name calling?

Posted by: pough | July 6, 2009 8:41 AM

Snowman, I am not being rude. I cannot believe that supposedly intelligent and educated people can be so dishonest when it comes to discussing the science of climate change.

Anyone who has been exposed to an even rudimentary science education will see at once that AGW deniers are not being honest in their discussions. They completely disregard simple science facts and methodology in their zeal to refuse to accpet that what we are doing to the atmosphere will have harmful effects to future generations. They are so arrogant and selfish in their attitude that it makes most caring people very angry.

What gives you the right, Snowman, to leave our children and their children with an environment which will result in untold suffering?

Anyone who has truly studied science will see that it is you deniers who are distorting scientific facts. There is an excuse for ignorance but no excuse for deliberately being dishonest about what is happening to our climate.

Unfortunately, there are a number of dishonest people who are infesting the science blogs with the intent of distorting the accepted science of climate change. I really don't understand the motives behind such behaviour unless they are directly influenced and funded by the very companies who are destroying our environment. Such behaviour is not just restricted to climate change but is found in many other areas where unscrupulous companies are destroying the environment in order to bolster their bottom line.

Posted by: Ian Forrester | July 6, 2009 3:16 PM

For a second there Adam i thought you were describing yourself, just kidding dont get too upset.

Richard is simply trying to mount a case against your beliefs but as always the goal posts keep on moving.

For example you say the temp increase is caused by increased CO2, this statement can only be based on opinion. Richard replies with observational data which shows the temps per decade have not changed.

There is then a call to arms and because of what he says he is labled a heretic, as always his views are not debated in any scientific way he is just simply lambasted. This process is repeated over and over again.

For example not one of you lot have actually produced any feasable reason for why the temp trend per decade (as described by Richard post #66) has not changed even though CO2 emissions have increased steadily or at a greater rate.

Your lack of response (sarcasm and ridicule aside) can only suggest one thing, and that is you cannot explain it. Rather than state this simple fact you ignore his post and launch into a denier bashing tirade.

So i suggest you try this, reply to post #66 in a polite, honest and courteous manner. If you cannot explain why CO2 levels have had nil effect on the temp trend then just say so.

Posted by: crakar14 | July 6, 2009 6:17 PM

Coby, Re #90
Just briefly, Why do you think that average Annual ice sea levels that you have referred to are relevant or meaningful?
From post #14 "The take away lesson is not to get distracted by natural variations, but look at trends." and just after that- "Tilo, why no comment from you about the big downward jump in the Antarctic sea ice extent?"
Trends Artic - Sept 79 - Sept 2008 -11.1%/ decade
Antartic March 79 - March 2009 +4.7%/ decade
""Compared to previous Mays, ice extent in May 2009 is about average": why do you think that is relevant?" Because Jan, Feb, March, April 09 were well below average and May average shows decided less warming in May.
Here is the important issue The assertions made by the warmers are: there is DANGEROUS global warming happening due to anthropogenic emmissions of greenhouse gasses chiefly CO2. The ice caps will melt, sea levels will rise catastrophically, hurricanes and cyclones will increase in intensity, there will be widespread droughts, and deaths due to heat waves. There is scant evidence for all this. This is whats important. The scientific method, what we are taught here in secondary school - if the evidence doesnt support the hypothesis discard it.

Posted by: Richard | July 7, 2009 12:42 AM

Adam,
"There's no reason why the numbers HAVE to be different. Why do you think they need to be?"
1. If they are not different then how can you say the second trend is due to CO2 and Anthropogenic? Where is the anthropogenic signature?
2. IPCC claims and the AGW hypothesis states the warming should increase but it doesnt.
3. This warming besides being no different from that earlier in the 20th century is nothing abnormal if we take the previous proxy temperature records when no CO2 effect was there.

Posted by: Richard | July 7, 2009 1:58 AM

Snowman wrote:

I find it strange. Don't you, even a little?

Not in the least. There are a few reasons.

1. Scientists (and many interested in science) tend to be more interested in the truth than in PR.

2. Anyone who sticks with the truth is at a disadvantage in a debate, and it's frustrating.

3. This is a serious subject. The people getting upset are quite certain that the effects of global warming will be very harmful. Who wouldn't get upset at someone recommending not wearing a helmet and claiming Squished Head Syndrome isn't as bad as the so-called experts would have us believe?

4. You are one of many gadflies. Every few weeks, as certain as rain in Vancouver, people like you wander in to a science forum and proclaim superior knowledge to the thousands of very intelligent people who actually study the subject, likely because you read the blog of a hack and it's more pleasant for your ideology to accept. It's not new, it's not smart and it's not interesting any more.

5. This is the internet. Welcome to it. You should be aware that it's no more polite than any other crowded place, possibly less so because of the dehumanizing effect of the lack of real human faces.

So either you're ignorant of those very obvious facts or else you're lying about finding it strange as a way to score rhetorical points.

Posted by: pough | July 7, 2009 8:01 AM

Vancouver you say pough. I hadn't realized you were based in the great white north. That explains a good deal. You could do with a bit of global warming, mate. It might liven the place up.

How interesting, though, that so many of the warmists seem to be based in Canada, the ground zero - the fons et origo - of political correctness.

Posted by: snowman | July 7, 2009 2:22 PM

Coby, Some comments on your post above.

"The very first thing to note about a response to a CO2 rise, is that an increase in the temperature of the global climate is completely expected." - Agreed
"So, it makes sense that it should happen. Is it?" (I would have said isn't it, but thats being trivial) - It may make sense, and thats the basis of a hypothesis, but then you have to see how the hypothesis pans out, in this case it doesnt.

"We need to eliminate other potential causes. Maybe it's the sun? Maybe it's natural causes [hand wave]?"

(No no Coby a hand wave is not natural causes, its definitely anthropogenic. But the sun and cosmic rays are. Maybe its the same "natural causes" that the IPCC refers to?)

"Maybe it's volcanoes? Maybe it's geothermal? Maybe it's galactic cosmic rays? Well, the sun has not changed its output significantly since the fifities, or enough overall to explain the degree of warming."

Not so Coby. From the SORCE people who study the sun at NASA - "Despite all that scientists have learned about solar irradiance over the past few decades, they are still a long way from forecasting changes in the solar cycles or incorporating these changes into climate models. One of their biggest obstacles has been technology. Because even the smallest shifts in solar energy can affect climate drastically, measurements of solar radiation have to be extremely precise. Instruments in use today still are subject to a great deal of uncertainty."

Then again TSI is not the only measure of the suns effect on our atmosphere. There is the variation of TSI over the solar spectrum, the solar wind, which is more active during an active sun. The sun since the 1990's has been the most active in a 1,000 years.

"Cosmic rays is a pretty far fetched grasp at straws." Thats your opinion.
"The connection is only plausible, far from demonstrable, it has been looked for and not found"

There was a recent "study" by Pierce and Adams in Geophysical Research Letters, who claimed their "model" showed that changes in cosmic rays are two orders of magnitude too feeble to cause the changes in clouds.

As it happens it is demonstrable and awaits an experiment in CERN called CLOUD. The experiment comprises of cylindrical cloud chambers which are exposed to an adjustable particle beam which simulates GCRs at any altitude or latitude. The chambers are filled with air, water vapor, trace gases and aerosols and can be operated at any temperature or pressure found in the terrestrial atmosphere. Till the results of that experiment are known the demise of the Cosmic Ray theory has been greatly exagggerated.

"An increasingly enhanced greenhouse effect should cause an energy imbalance between incoming sunlight and outgoing infrared radiation."

Wrong! If the Earth was warming due to any causes, which is not disputed, there would be an energy imbalance.

"So to summarize: we know anthropogenic climate change is real because there is no other likely candidate cause"

The logic is wrong again. This is like arguing since we have not found the missing link as yet or there are gaps in the fossil record (evidence we have not found as yet) that intelligent design is the only explanation of evolution.

"The next step is usually to perform an experiment and thus confirm or deny your hypothesis when your expecations are or are not met. Unfortunately, there is only one planet and one timeline to move it along, so that is out."

There is another way to confirm or deny your hypothesis - see if the predictions made by your hypothesis are correct. In this case the predictions have not proved to be correct.

Posted by: Richard | July 8, 2009 11:36 PM

Snowman, what you should do now is in no way respond to what I said, except to change the subject and note something completely different as "interesting", as though there were still some reason for people to doubt based purely on psychology.

Oh wait. That's exactly what you did. Sorry. You're keeping on top of things. Nevermind.

Posted by: pough | July 9, 2009 9:16 AM

Regarding my post at 9:31 am, July 9.

"BUT BUT BUT MODELING IS VALID" should read
"BUT BUT BUT MODELING ISN'T VALID"

Bad place to make a silly mistake.

Posted by: Adam | July 9, 2009 9:33 AM

Coby - You reprove Richard too readily. His edit is not extremely dishonest. On the contrary, it captures, as good editing should, the essential point of your remark, stripped of elaboration.

This allows him to direct his comments to the key issue, ignoring matters which - whatever other merit they may have - are hardly the sine qua non of your argument.

Such directness and lucidity are the only way we can make progress, and, one regrets to say, these are qualities that are too often lacking in this forum.

Posted by: Snowman | July 9, 2009 3:52 PM

We are all keenly aware of the irony, Ian, in that the qualities your contributions conspicuously lack are facts. Rants, on the other hand - well, you are good at those.

Posted by: snowman | July 9, 2009 4:13 PM

Snowman, I can assure you that I am better educated about climate science than you. I am also a very honest person and hate it when I see the dishonesty portrayed by deniers like you.

Have you even read a paper from the peer reviewed scientific literature. It would appear that the only sources for your misinformation are denier web sites. You must be extremely gullible to accept the nonsense portrayed there when it has been explained over and over again how wrong it is.

Posted by: Ian Forrester | July 9, 2009 4:27 PM

Post 119 made me laugh, surely it got at least a chuckle out of Coby.

Looking at the quote in question it is a shame that Richard did not supply the full quote as it gave Coby an "out" in that he could then avoid responding to it and simply lambasted him on a trivial matter. This is a classic move by someone who has no answers.

However Coby may have erred in supplying the entire quote lets beak it down a bit.

"So to summarize: we know anthropogenic climate change is real because there is no other likely candidate cause,

(Really? no other likely candidate "THAT WE KNOW OF" should have been added)

the CO2 rise is unquestionably the result of our activities,

(Much debate about this as in how much is natural etc)

the particulars of the warming signature are consistent with an enhanced greenhouse effect

(This statement is incorrect; the hotspot above the tropics is the signature the author is referring to and after many years of looking this signature cannot be found.)

and the whole phenomenon is entirely consistent with very long standing theories and expectations."

(The key word here is “expectations� which I take to mean computer model predictions. All the IPCC models predicted the temps would continue to rise beyond 2000. Of course we all now know this not to be true.)

Posted by: crakar14 | July 9, 2009 8:30 PM

Coby

"So to summarize: we know anthropogenic climate change is real because there is no other likely candidate cause, the CO2 rise is unquestionably the result of our activities, the particulars of the warming signature are consistent with an enhanced greenhouse effect and the whole phenomenon is entirely consistent with very long standing theories and expectations."

The edit was not dishonest but maybe misleading (to you). So here is an elaboration:
There ARE other likely candidate causes - in short the Sun. There are hypothesis and some data to support how precisely this happens but just because we do not today have the proof, (for example the CLOUD experiment is scheduled for 2011), doesnt mean that its not true. Am I clear now? (Because this explanation threatens the AGW hypothesis it has been attacked most vehemently by the warmers).

One thing we know - something caused the temperatures to go up, at the end of the ice ages, (the initial cause). This the warmers acknowledge is the Sun and they repeat the mantra Milankovitch cycles. But the Milankovitch cycles of 100,000 years that repeatedly pulled the Earth out of the ice ages is far too weak to explain this. Obviously the "sensitivity" of this (essentially solar) forcing is very high and it must be helped on with something else (probably clouds). And no not CO2 - that rose much later.

Again something plunged the Earth repeatedly back into the ice ages after about 10,000 years. When this happened the CO2 was rising and continued to do so as the temperatures plunged. CO2 appeared powerless then, why should it be all powerful now.

We simply do not know enough about the Sun and the way it acts on our atmosphere to have dismissed its influence in the temperature rise of the last 3 decades, or indeed the rises AND falls previously.

Then the most important bit "The next step is usually to perform an experiment and thus confirm or deny your hypothesis when your expecations are or are not met. Unfortunately, there is only one planet and one timeline to move it along, so that is out."

There is another way to confirm or deny your hypothesis - to see if the predictions made by your hypothesis are correct. In fact this is the most important way. Newtons theory of Gravity was confirmed by the calculated reappearance of Haley's comet. If even one prediction is found to be incorrect then the whole hypothesis is rejected. I will show you how several predictions of the IPCC dont match up. Thats for another post.

Finally my post #107 and Adams reply. Yes it is true I do not trust models very much, but then they do not seem to agree with each other either. The explanation of the first rise given by Adam doesnt seem to match up looking at the Graph. But thats not the point. This is it:

To distinguish the extremely short period, climatically and geologically speaking, of 3 decades from a previous 3 decades, were it not for the elaborate models and complicated explanations of the IPCC it would have fitted in right there with the natural rise of temperatures since the little ice age. The total rise around 0.6C is also well within the range of temperature variations of the past.

The Parsimony Principle or Occam's razor in science demands that additional reasons should not be given without necessity. There is no reason for that elaborate additional reason for the temperature rise.

"How about a source for that quote so we can verify it and understand its context? Regardless, an inability to forecast says nothing about what has already happened and uncertainty is hardly a support for the case for solar and definitely does not support your "Not so" response to my assertion that TSI has not changed enough, a response with a high degree of certainty on your part."

The source - http://earthobservatory.nasa.gov/Features/SORCE/sorce_05.php

And we do not "know" what has aleady happened.

"the most accurate estimates of the long-term average TSI are uncertain by several times the amplitude of the 11 year cycle. This large uncertainty in absolute calibration of the instruments means that any possible trend from one 11 year cycle to the next, the most important change for global warming, is not known accurately enough to even decide whether the trend is positive, negative, or zero."

"Even larger uncertainties exist for measurements of the amount of solar radiation that is absorbed by the Earth’s atmosphere, ocean, and land."

"With solar radiation, a 5 percent difference is huge. A difference of even 1 percent would completely throw off climate models of global warming "

"The other big problem scientists face is too little data. Even in instances when solar energy measurements are accurate, researchers often don’t have enough information with which to draw conclusions. Building models to forecast long term trends, in particular, requires a tremendous amount of past data on those trends. At this time, scientists only have roughly twenty years of satellite data on the Sun —an equivalent of just two 11-year cycles. Most of the data researchers do have on the Sun are for TSI. Relatively very little data have been gathered on the spectral changes in the Sun."

"The dearth of spectral data presents another serious obstacle for climate modelers since distinct wavelengths are absorbed by different components of the Earth’s climate system, which react differently with one another as their energy levels change."

Posted by: Richard | July 9, 2009 11:39 PM

Interesting to see you invoking Occam's razor, Richard. For some reason, the concept seems to be beyond the warmists. When I mentioned it some time ago I was called, variously, a scumball, a liar and a pedlar of junk philosophy.

I hope you have more luck.

Posted by: snowman | July 10, 2009 4:57 AM

Snowman -

Interesting to see you invoking Occam's razor, Richard. For some reason, the concept seems to be beyond the warmists. When I mentioned it some time ago I was called, variously, a scumball, a liar and a pedlar of junk philosophy.

Denialists are usually attacked for invoking Occam's Razor incorrectly. Just because an explanation is 'simpler' doesn't mean it is correct. In a scientific usage, you can say that the simpler of two explanations for which there is equal evidence is likely correct. This is a stronger form of Occam's Razor.
http://www.physics.adelaide.edu.au/~dkoks/Faq/General/occam.html

Analogous example: It is far simpler to say that all species on Earth always existed as they are, rather than evolved from common descent. However, the evidence does not support this explanation, so it has to be discarded, regardless of its simplicity.

For some reason (but not particularly surprisingly), denialists don't understand the basic philosophy of science.

Posted by: Adam | July 10, 2009 8:38 AM

Without that basic requirement, it would be possible to justify any number of fanciful notions by appealing to an abstract concept of simplicity.

Such as: the warming is completely in line with natural phenomena since the little ice age. (Which is what Richard was originally using it to discuss in post #122).

This ignores all the evidence that has been presented regarding global warming, but (in my estimation) three in particular:
1) The Little Ice Age was a localized effect, and the extent not fully understood
2) The rapid increase in temperature over 'normal' historical temperature change
3) The known effect of increasing temperature from increasing CO2 in the atmosphere, and the observation that the CO2 concentration has been increasing rapidly since the beginning of the Industrial Revolution (combined with knowledge of anthropogenic CO2 emissions).

The counter-evidence supplied is "HEY, JUST LOOK AT THE GRAPH!"

This is a misapplication of Occam's Razor, and is being using to justify fanciful notions by appealing to an abstract concept of simplicity.

Posted by: Adam | July 10, 2009 11:11 AM

Snowman,

from Isaac Newton's Principia Mathematica, translated from the latin:
RULE 1 - "We are to admit no more causes of natural things, than such as are both true and sufficient to explain their appearances." If therefore whatever caused a warming earlier naturally, do not invoke another cause for a similar warming later. "for Nature is pleased with simplicity, and affects not the pomp of superfluous causes."

RULE II - "Therefore to the same natural effects we must, as far as possible, assign the same causes. As to respiration in a man, and in a beast; the descent of stones in Europe and in America; the light of`our culinary fire and of the sun; the reflection of light in the earth, and in the planets" or Global warming or cooling. Do not therefore invoke another cause for a similar effect.

"We are certainly not to .. recede from the analogy of Nature, which is wont to be simple, and always consonant to itself."

Thomas Aquinas "If a thing can be done adequately by means of one, it is superfluous to do it by means of several; for we observe that nature does not employ two instruments where one suffices"

Posted by: Richard | July 10, 2009 12:56 PM

Adam,

"Over the past 400,000 years (at least) carbon dioxide concentrations never got much above 300ppm. Today, we are rapidly approaching 400ppm. There's a matter of scale you are completely neglecting; .. So, carbon dioxide isn't "all powerful" now, it's the fact that there is a significantly higher concentration, and that concentration is increasing."

I am afraid the matter of scale is what is deceiving you, as illustrated in that graph you refer me to. I dont blame you, you havent had the advantage of my maths and science teacher in school to explain the basics. Plot that same graph using the 0 coordinate and suddenly the "dramatic" rise doesnt seem so dramatic after all.

Then remember what we are talking about is parts per million. Plot the same graph as a percentage of the Earth's atmosphere and then you get a dead straight horizontal line. The "dramatic" rise cannot be discerned at all.

Granted CO2 is a greenhouse gas, but theoretically it will raise the global temperature by 1C, if it increases from 280 ppm to 560 ppm, provided all else in our climatic system remains constant. According to IPCC this effect will be enhanced and the Global temperatures should increase by 3C. Again most of this increase should take place in the first half of the increase, ie upto 420 ppm (say about 2C) and a lesser amount during the second half.

Well what do you know, CO2 has already reached 390 ppm (fast approaching 400 as you say) and the temperature during this time has climbed a scant 0.6C and dropping by all indications instead of climbing.

It appears as though CO2 is more or less an impotent follower of the climate and not a driver at all, as in the past.

Posted by: Richard | July 10, 2009 3:31 PM

"The same can you used to "prove" that an asteroid or comet didn't cause dinosaurs to go extinct, because all previous extinctions of dinosaur species were caused by something else."

I thought that the dinosaurs went extinct only once? I could be wrong though and its not important.

The thing is I am not trying to "prove" anything. It is the AGW hypothesis that has to prove itself.

I have pointed out in #132 just one important instance where it miserably fails to do so.

No the Parsimony Principle is invoked to debar the AGW hypothesis in the first place. There is no need for it when the temperature increases are well within the range of natural variability.

We have not figured out the exact causes and mechanisms of natural variability, which depend primarily on the Sun, but in ways that we do not as yet know for certain.

We should do that first before invoking an entirely new hypothesis to explain the last 3 decades, which we are to believe are entirely different from anything else that has preceded it, despite looking very similar.

Posted by: Richard | July 10, 2009 5:28 PM

We have not figured out the exact causes and mechanisms of natural variability, which depend primarily on the Sun, but in ways that we do not as yet know for certain.

We should do that first before invoking an entirely new hypothesis to explain the last 3 decades, which we are to believe are entirely different from anything else that has preceded it, despite looking very similar.

It depends on the Sun but in ways we do not yet know.

So we shouldn't invoke an entirely new hypothesis (by which you mean CO2 forced warming, even though it's over 150 years old, so not "new") but instead should invoke an entirely new solar-based hypothesis that some brand-new process we can't observe, can't theorize, and haven't imaged is the cause.

You're being ridiculous.

If you think scientists are going to go down the path of rejecting known physics and embrace some "sky fairies are doing it using the sun" hypothesis, you know nothing of science.

Posted by: dhogaza | July 10, 2009 6:05 PM

Ask yourself this: What is the difference between the believer and the skeptic in this case? Both can present an array of science, anecdotal evidence, and graphs that lead to seemingly logical conclusions. Just because one does not believe the other, it does not make either true.

Throw out the "science". The belief in anthropogenic climate change has more to do with politics than anything. Only humans (who are a relatively new feature on a 4.5 Billion year old planet) have the ability and, to some degree, arrogance to make climate conclusions based on 10, 25, 50, 100, 1000, or even 100,000 years of data.

The simple truth is that we do not fully understand our climate. The notion that we can make conclusions based on the data we have is truly ridiculous. So, present all the data you want whether you are a believer or a skeptic -- it is still a best guess, and nothing more.

The best science out there should tell us that our time as a species on this planet is relatively limited. Our species will be but a pebble in the sea of time that this planet has seen. Hopefully the next intelligent inhabitants of the earth don't waste their time creating fear and restricting liberty in the name of "science".

Posted by: Jason | July 12, 2009 10:46 AM

Jason -

Throw out the "science". The belief in anthropogenic climate change has more to do with politics than anything. Only humans (who are a relatively new feature on a 4.5 Billion year old planet) have the ability and, to some degree, arrogance to make climate conclusions based on 10, 25, 50, 100, 1000, or even 100,000 years of data.

What's 'arrogant' about making conclusions from 100, 1000 or 100,000 of data if we reasonably need between 20 and 30 years to make statistically valid statements about climate (in this particular case, temperature). Do you have a reason for making such a radical statement, or are you just unthinkingly calling all climate science into question so you don't have to deal with the conclusions?
This post might be useful for you (I reference it a lot, so it might even be the second time it appears on this comment thread)
http://moregrumbinescience.blogspot.com/2009/01/results-on-deciding-trends.html

Hopefully the next intelligent inhabitants of the earth don't waste their time creating fear and restricting liberty in the name of "science".

"Restricting liberty" is an interesting term you used here. Just out of curiosity, what liberties have you lost in the name of scare-quote science end-scare-quote?

Posted by: Adam | July 12, 2009 1:46 PM

Dhogaza

I really wish you would stop all this ranting and posturing. You are clearly no match for Richard and it is embarrassing watching you trying to argue with him. Save yourself further humiliation, please.

Posted by: Snowman | July 12, 2009 3:01 PM

Dhogaza

I have no idea who Richard is, and he certainly doesn't know me. It is true that I am a fan, though. I admire his intellectual strength, analytical ability and clarity of presentation.

When I say that it is embarrassing watching you trying to match him, I mean that quite sincerely. I cringe every time you try, and I am quite sure that others in this forum feel the same. Quite simply, Richard is in a different league and it is time you acknowledged that fact. It is certainly painfully apparent to everyone else.

So, Dhogaza, enough already. Confine yourself to areas where you won't humiliate yourself further.

Posted by: snowman | July 12, 2009 3:47 PM

Interesting comment about Richard and snowman possibly being one and the same. Since they both appear to be from the UK I'm sure there are lots of people involved in education over there who are hoping that they are one and the same since they would not like to think that their education system is capable of "graduating" two such uninformned and dishonest students.

I put the word graduating in quotes since it is now applied to very low levels of the education system such as kindergarten and elementary school. I am sure that I can find students in elementary school who know a lot more about climate change and environmental science than these two apologies for the educated class do.

Posted by: Ian Forrester | July 12, 2009 4:40 PM

Ok I'm trying it here my reply to Dhogaza in plimers page

dhogaza

My example of a positive or negative feedback mechanism is correct. Can you give a clearer example?

From the exchanges I have had with you, your understanding of maths and science doesnt compare with mine. I had to give you a maths lesson (in simple addition) I remember. I wonder if you know what the scientific method is for testing a hypothesis.

There is absolutely no evidence of anthropogenic warming in the temperature records - I have already pointed this out here in posts #66 and #107.

To recap there are 2 trends roughly between 1911 to 1944 (give or take a year or two either way depending on which data you are looking at NOAA or Hadley) and 1976 to 2008 which have similar slopes. To distinguish between the two you have to accept the elaborate explanation of the IPCC. The alternative explanation - the second trend is natural like the first. There is no need to assume anything else.

Well if its not IPCC's elaborate explanation, what then could be the possible cause of the warming? I think it is the sun (and I have given my reasons). But even if we do not know what it is at this time we do not compulsarily have to assume something/anything, right/wrong in the meantime.

I have pointed out in #68 in Plimers page, and I think here too, the evidence so far does not support the AGW hypothesis.

Posted by: Richard | July 15, 2009 10:57 PM

It's a bit hypocritical to nit-pick the poor correlation between temperature and solar activity during the ~40 years that they seem poorly correlated, then turn right around and completely ignore the poor correlation between CO2 levels/rise rate and temperature across several similar time periods. The "it must be particulates" excuse is no more than an obfuscation that does not hold up under detailed scrutiny! The wrong hemisphere had all the particulates increases as the hemisphere that actually warmed during the period of 'non-correlation'. You can't then sum the temperature results of both hemispheres and claim that the cooling hemisphere caused the other to arm. That's just a dishonest obfuscation, pure and simple! And in the end, there are more particulate emissions NOW than during the periods of poor correlation.

Posted by: Jim Rennison | July 16, 2009 7:24 AM

Jim Rennison -

It's a bit hypocritical to nit-pick the poor correlation between temperature and solar activity during the ~40 years that they seem poorly correlated, then turn right around and completely ignore the poor correlation between CO2 levels/rise rate and temperature across several similar time periods.

See dhogaza's post for the supposed 'poor correlation between CO2 and Temp'.
And better yet, see here for a more comprehensive analysis:
http://moregrumbinescience.blogspot.com/2009/03/does-co2-correlate-with-temperature.html

Also, you might call it 'nit-picking' but I call it 'a fundamental flaw in Richard's analysis.' Richard claims that the trends between the two periods he calls out are approximately the same, so they cause of both should be the same.

Unfortunately, when we examine the various influences on global temperature, we see vast differences in the latter period than in the earlier one(steady solar influence - per my post#149, more rapidly increasing CO2 concentrations - per dhogaza's post #150, etc.) so we know that his explanation cannot be right. It remains to be seen whether Richard will actually address this, or if he will simply repeat his claim again (as he has done in the past).

The "it must be particulates" excuse is no more than an obfuscation that does not hold up under detailed scrutiny!

What "it must be particulates" are you referring to? For what time period, or what specifically are you trying to say?

Posted by: Adam | July 16, 2009 8:16 AM

Adam - I have no idea about the new graph you have pulled out; whether that is correct or how and why that disproves the sun being a cause, or proves that it isnt.

Solar cycle length is NOT = the influence of the sun on our climate, though it may be connected indirectly as an indicator of solar activity.

Solar influence is directly related to irradiance or TSI, which IPCC seems to think is the sole or major influence of the sun, and which does not vary much, but far more directly to solar wind, and geomagnetic activity. The variation of TSI over the solar spectrum is also not well known.

Let us be consistent and stick with the IPCC graph courtesy of Global Warming Art at the top of this page.

That shows that the sun's forcing (red line) hasnt changed much since about 1920 or so and if we are to believe that graph then we have to accept CO2 is the cause of the temperature rise of the last 32 years. QED

However I pointed out in #108 that we simply do not know enough about the sun and the ways in which it influences our atmosphere, to make such a definitive analysis, or dismiss its influence too readily.

Me #108 - "From the SORCE people who study the sun at NASA - "Despite all that scientists have learned about solar irradiance over the past few decades, they are still a long way from forecasting changes in the solar cycles or incorporating these changes into climate models."

Coby - "How about a source for that quote so we can verify it and understand its context? Regardless, an inability to forecast says nothing about what has already happened and uncertainty is hardly a support for the case for solar and definitely does not support your "Not so" response to my assertion that TSI has not changed enough, a response with a high degree of certainty on your part."

Me - #122 The source - http://earthobservatory.nasa.gov/Features/SORCE/sorce_05.php

And we do not "know" what has already happened. (With such uncertainties we cant be sure as to what is happening now leave alone have absolute certainty about what has happened in the past)

Coby - Silence

Posted by: Richard | July 16, 2009 2:37 PM

Richard

I have no idea about the new graph you have pulled out; whether that is correct or how and why that disproves the sun being a cause, or proves that it isnt.

It doesn't disprove the sun as a cause. It does disprove your assertion that since the two periods you called out (early 20th century and late 20th century) have similar temperature increases, we should assume that they result from the same cause. This graph shows simply that this assertion is incorrect. Variations in solar activity obviously affect global temperatures, but it is insufficient to explain the full 20th century temperature increase. This is where the "Climate Change Attribution" graph comes in, as it provides an explains the observed temperature rise.

However I pointed out in #108 that we simply do not know enough about the sun and the ways in which it influences our atmosphere, to make such a definitive analysis, or dismiss its influence too readily.

For someone so cautious about dismissing causes too prematurely, you certainly do not hesitate to discount the effects of greenhouse gases.

Posted by: Adam | July 16, 2009 4:21 PM

Richard said: "I said that we cannot tell from those trends that there is a different cause from the same effect".

Just goes to show that he doesn't know the difference between cause and effect. Why am I not surprised?

Richard, anthropogenic CO2 emissions are causing temperatures to rise. That is the effect.

Posted by: Ian Forrester | July 16, 2009 6:10 PM

Richard said: "There is no evidence from the temperature records of ANTHROPOGENIC global warming." That is correct but is incomplete. Of course temperature measurements by them selves cannot tell you what is causing the rise, anthropogenic or otherwise.

The evidence for the anthropogenic CO2 rise as a cause of the temperature rise comes from other evidence such as isotope analysis and from basic physics (CO2 absorbs IR and causes the molecules to become more energized thus increasing their temperature. Through collisions this energy is transferred to other molecules).

Posted by: Ian Forrester | July 16, 2009 6:20 PM

The evidence I have seen on greenhouse gases does not say that CO2 is absorbing all the radiation it can. It says that CO2 is absorbing all the radiation AVAILABLE in the limited, small wavebands which it is capable of absorbing.
Imagine a sports stadium with an audience of 50,000. In this audience, which represents atmospheric molecules, are 2 people (CO2), each carrying a small source of heat, such as a lighted candle. Does it make any sense to say that they are warming, not just the whole audience but the stadium as well?
The effect of CO2 on atmospheric warming is of the order of 1% of the effect of water vapour: has the variation of this been measured?
As stated above, global warming is greater at night than during the day. We all know that a cloudy night produces obvious warming while cloud during the day is cooling: is the day/night distribution of cloud being studied?
There is much evidence of CO2/warming correlation. The large majority of the Earth's surface is water - up to kilometres deep; this water is saturated with CO2 and, as the temperature rises, some of the CO2 evaporates, increasing the atmospheric concentration: Al Gore's tail is wagging his dog!

Posted by: clem_at_is | November 11, 2009 9:02 AM

I've addressed the "correlation is not causation" objection with this analysis.

Posted by: Joseph | December 15, 2009 7:19 AM