Previously I criticised this world bank report, because of some injudicious choice of phrasing. However, various people suggested that I could consider actually reading the report and seeing what it had to say. Obviously I'm not going to do that in detail, but I can try skimming it. I wrote some stuff whinging that their use of "likely" and "could" was ill-defined, but decided that was boring, so deleted it and started again.
Oh, and yes this is yet another excuse for not writing about sea ice; but I can at least formally acknowledge losing my bet with Neven (and one of them with Crandles).
How Likely is a 4°C World?
They ask. And its a good question, well at least if you're writing a report about a +4oC world its an essential question. So, what's their answer?
The emission pledges made at the climate conventions in Copenhagen and Cancun, if fully met, place the world on a trajectory for a global mean warming of well over 3°C. Even if these pledges
are fully implemented there is still about a 20 percent chance of exceeding 4°C in 2100 . If these pledges are not met then there is a much higher likelihood—more than 40 percent—of warming exceeding 4°C by 2100...
I'm not sure that's a desperately useful way of looking at future CO2 trajectories, but its plausible, at least to the sort of people that probably went to C or to C and took them seriously (I did neither; that reminds me, Timmy has another excellent article about carbon tax which you should certainly read, unless you already agree with everything he says there. Perhaps ...Texas becomes uninhabitable for weather reasons not cultural ones... is enough to tempt you?).
Footnote 10, which is their methodology, is interesting:
Probabilities of warming projections are based on the approach of (Meinshausen et al. 2011), which involves running a climate model ensemble of 600 realizations for each emissions scenario. In the simulations each ensemble member is driven by a different set of climate-model parameters that define the climate-system response, including parameters determining climate sensitivity, carbon cycle characteristics, and many others. Randomly drawn parameter sets that do not allow the climate model to reproduce a set of observed climate variables over the past centuries (within certain tolerable “accuracy” levels) are filtered out and not used for the projections, leaving the 600 realizations that are assumed to have adequate predictive skill.
I've heard of this idea, but its not something I'm used to seeing being used. I assume it produces answers not too dissimilar to the usual throw-a-stack-of-GCMs-against-the-wall kind of stuff in IPCC, and who is to say which is better. Probably they should all be looked at more as representative and scenario-generating rather than serious attempts to constrain likely future ranges. But then, I'm getting increasingly out of touch with this stuff. Ask that nice Dr Annan instead.
But anyway: what I'd take from that, summarised in a way I could agree with, is that given the CO2 scenarios we can't rule out, it is possible but less than even-odds-likely, that we'll exceed 4oC by 2100. Note that (their fig 20) RCP 6 is somewhat lower than A1B from the olde dayes.
They then point out that lots of CO2 leads to ocean acidification as a problem of its own, which I assume is correct (I didn't read it, or the drought stuff, or the cyclones stuff). And so on. It becomes clear that this is mostly the std stuff, and they are drawing from the std resources that you'd hope they'd use.
So if you strip away the over-emotive language used in some parts of the report, most obviously in its foreword, you're left with this from the executive summary:
A 4°C world would be one of unprecedented heat waves, severe drought, and major floods in many regions, with serious impacts on ecosystems and associated services. But with action, a 4°C world can be avoided and we can likely hold warming below 2°C
which seems fair enough (apart from the extraneous comma in the last sentence, of course, which isn't fair at all).
I would expect to see the Meinshousen et al (and there's a follow up by Rogelj this year, I think) in the IPCC next year.
They were both referenced in the recent UNEP report: http://www.unep.org/publications/ebooks/emissionsgap2012/
The advantage of there method is that you can get thelimits on the range of parameters. Did something like this for fitting some spectra once.
I can at least formally acknowledge losing my bet with Neven
William, you can send the 10K to the Swiss account number I have given you last year.
"A 4°C world would be one of unprecedented heat waves, severe drought, and major floods in many regions, with serious impacts on ecosystems and associated services. But with action, a 4°C world can be avoided and we can likely hold warming below 2°C"
Sort of sounds familiar already this 4C world.
Or is that over reporting?
William, you can send the 10K to the Swiss account number I have given you last year.
Post of the season ... :) :)
What dhogaza wrote.
"But anyway: what I’d take from that, summarised in a way I could agree with, is that given the CO2 scenarios we can’t rule out, it is possible but less than even-odds-likely, that we’ll exceed 4oC by 2100. Note that (their fig 20) RCP 6 is somewhat lower than A1B from the olde dayes."
This assumes that it is likely the commitments will be adhered to. That is less than obvious at this stage.
"Excellent" post from Tim Worstall?! The guy goes into Econ 101-level detail about a carbon tax imagines he's solved the entire problem. Man, life is easy for a libertarian blogger.
[No, he isn't claiming to have solved the whole problem. But he is pointing out a number of facts that seem to have escape most commentators. Hopefully you're familiar with, and agree with, all he says: but clearly many people aren't -W]
Notice how he leaves out some of the important issues of cost-benefit analysis and taxes (on which his argument hinges) that, you know, serious thinkers on this issue are discussing and have fundamental implications for the feasibility of an optimal approach to climate policy:
-The Stern vs. Nordhaus discussion on discount rates and inter-generational concerns
[Well he hasn't left out the C-B; he's pointed you at Stern. At the level he's talking at, some dropping of detail is inevitable. And it doesn't really help you anyway I'm afraid. Yes, there are indeed issues about how to price these externalities; Stern comes close to the top of the range, so Timmy is being "generous" using him. You need to be a fairly committed ecological-disasterist to go higher -W]
-Problems of dealing with uncertainties and non-linear damage in a CBA framework (e.g. Weitzman's Dismal Theorem)
[You talk about Econ 101 and then fall for that? http://julesandjames.blogspot.co.uk/2007/10/weitzmans-dismal-theorem.ht… (or, indeed, me: http://scienceblogs.com/stoat/2007/10/06/weitzmans-dismal-theorem/) -W]
-The benefits of hedging to keep options open (e.g. Yohe)
[Yohe is just a collection of four letters to me. If you actually watned to discuss this, you'd have bothered to give a proper reference -W]
-Pros and cons of carbon taxes vs. ETS (e.g. Stavins)
[Ditto, except we're up to 7 letters now. IMO ETS is deeply stupid (e.g. http://scienceblogs.com/stoat/2011/06/06/carbon-tax-now-1/) and many of the people pushing it are clearly idiots (http://timworstall.com/2011/06/02/idiocy-on-carbon-permits/) -W]
-Technology R&D and innovation incentives (e.g. Acemoglu?)
[Yeah, so what? That all just folds in to carbon taxes invisibly -W]
Never mind the fact that most people don't believe you can accurately assign a value to future climate damage, which immediately throws the purely optimal approach that Tim advocates out the window. But then, that wouldn't make a snappy and snarky blog posting..
[I don't believe that you can do so, either. So what? We (as in society, the world, the people changing things) are, inevitably, going to end up making decisions about the future. Quite likely, they will be made in a muddled and incoherent way based on inadequate and inaccurate data by ill-informed people on the basis of their own stupid pet theory. That doesn't prevent the rest of us at least trying to talk sense. If you think Timmy is actually *wrong* then you would ideally present some kind of coherent critique. Saying he is *incomplete* is just the bleedin' obvious. Saying "his most important incompleteness is X" would be interesting, but you'll need to be specific rather than scatter-shotting -W]
I'm afraid I'll have to take severe issue with a particularly outrageous statement of yours, above.
'Extraneous comma' - how dare you!
It's just there, doing its job, harming nobody, only offering assistance to those who may need it.
All the more un-called for, given that you write;
"apart from the extraneous comma in the last sentence, of course,"
" In the simulations each ensemble member is driven by a different set of climate-model parameters that define the climate-system response, including parameters determining climate sensitivity, carbon cycle characteristics, and many others. Randomly drawn parameter sets that do not allow the climate model to reproduce a set of observed climate variables over the past centuries (within certain tolerable “accuracy” levels) are filtered out and not used for the projections, leaving the 600 realizations that are assumed to have adequate predictive skill."
This is actually similar to the MIT approach I linked to last time (though the MIT group used this approach for determining likely future emissions as well as climate impacts... also, I should probably go read the paper, but here it sounds like they are tossing the combinations which don't meet certain historical criteria and making the reminder equally likely, whereas the MIT group used a weighting function that assigned the greatest likelihood to those combinations of parameters that best matched historical observations)
[Getting a decent set of model runs that span the truth is really quite difficult, apart from anything else because we don't know where the truth is (if we did, of course, we wouldn't need to do this). The Met Office has worked on it, James A has written about it too. I have a strong feeling that MIT use a rather cut-down model, though. And I suspect M et al. do too -W]
There is serious disagreement about what you say is "fair enough", i.e. your assessment of the World Bank Report statement that "with action, a 4 C world can be avoided and we can likely hold warming below 2 C".
Eg: Bob Watson recently stated the 2 C target is "out the window". Watson has been involved in trying to understand what is possible for civilization to achieve since as far back as 1988 when he was centrally involved in the creation of the IPCC.
Anderson says Tyndall examined "all" projections such as the Stern Report that claimed to realistically asses what civilization can actually do about climate change, that found that 2 C and continued expanding prosperity for an ever larger group of humans on the planet is achievable, and, he emphatically asserts, found them "all" to be in serious error. "All" of them depend on fudged data, impossible assumptions, and poor analysis.
Anderson asserts "there is a widespread view that a 4 C future is incompatible with an organized global community, is likely to be beyond adaptation, is devastating to the majority of ecosystems and has a high probability of not being stable.
As opposed to many, I enjoy running and screaming and crying, AND rending my clothes, as I mindlessly blather on about the end of civilization, so I lap up BS like what Watson and Anderson are peddling, without thought.
But out of curiosity, I wondered what the calm thinkers such as you and Eli believe.
Is Anderson lying about the "widespread view"? Is he ignorant? What about Watson? Has he always been this out of touch with reality?
[Whether we get to +2 or +4 depends largely on CO2 emissions, and to a lesser extent on climate sensitivity. I'm personally rather dubious about getting as high as +4 by 2100. As to how dangerous either of those might be... that is very difficult.
The only thing I'd really endorse in Anderson's piece you link to is "The Cancun Agreement, the EU and the UK, all categorically state that temperatures must rise no more than 2°C. Understanding the probability of staying below (or of exceeding) 2°C is pivotal to any informed discussion of mitigation – an absence of clarity on this issue risks confusion and inappropriate policies. As it is, policy-makers (along with many academics and climate specialists) repeatedly make statements, emphasising the importance of staying below 2°C whilst at the same time proposing policies that imply a very high chance of exceeding 2°C".
What about his "Let’s look at a snapshot of a 4°C world."? We have "A global mean surface temperature rise of 4°C equates to around 5-6°C warming of global mean landsurface temperature. According to the UK’s Hadley Centre (Sanderson, 2011; New, 2011) a 4°C world would likely see the hottest days in China being 6-8°C warmer than the hottest days experienced in recent heat waves that China has struggled to cope with; Central Europe would see heat waves much like the one in 2003, but with 8°C on top of the highest temperatures..." and so on. I'm pretty unconvinced that given 90 years to adapt, we (humans) couldn't cope with that. As I've said before (but can't currently find) the only real way to get death and disaster is to consider ecosystem responses; alas I don't really know about that, so can't do it myself. Physically its pretty hard to get disaster out of even +4 oC, in my opinion -W]
I worry that the imposition of a carbon tax will impede further action afterwards. In Canada, we have several provinces that have put these taxes in place, and feel quite smugly green as a result. But they are pretty minimal, therefore of questionable effectiveness, and recent talk (esp.in BC) has been to lower if not abandon them. This seems also part of the strategy behind Grover Norquist's recent reluctant embrace: we'll give you a carbon tax, you shut the fuck up for ever after.
[You have to set them at a sane level, otherwise they are pointless. I've usually suggested they be introduced at a low level, so people can get happy with them as revenue-neutral, and then have them increased. If you have them set at the right level, of course, then no further action is required ;-) -W]
As you say, "the only thing" you'd "really endorse in Anderson's piece" (the written article I linked to in my previous comment) is that there have been a lot of political statements that categorically state 2 C must not be exceeded.
So when Anderson argues that 2 oC is not achieveable given the universal assumption that economic growth extending prosperity to an ever increasing number of human beings on the planet such as what is going on now, I assume you reject his analysis.
[I'm agreeing with Anderson that everyone goes around saying 2 oC would be bad and must not be allowed, but no-one is really doing anything to stop it. So I don't understand why you think I would reject that part of his analysis -W]
He supplies details, showing that "all" analysis by reports such as the Stern, etc., that support your view was based on BS. No matter.
[I don't know what you mean by that. But since you say "no matter" I won't worry -W]
And after arguing that the best civilization can do now is limit warming to about 3-4 degrees C, when he says:
"It is fair to say, based on many (and ongoing) discussion with climate change colleagues, that there is a widespread view that a 4 degree C future is incompatible with any reasonable characterization of an organized, equitable and civilized global community. A 4 degree C future is also beyond what many people think we can reasonably adapt to. Besides the global society, such a future will also be devastating for many if not the majority of ecosystems". And, citing Lenton 2008, he says "beyond this, and perhaps even more alarmingly, there is a possibility that a 4 degree C world would not be stable, and that it might lead to a range of natural feedbacks pushing temperatures still higher".
I assume you reject it.
[Well, presumably you read what I wrote -W]
But these were my assumptions before I originally commented.
Your post makes your views clear. Once you "strip away the over-emotive" language", you say, what the World Bank says is "fair enough", i.e. 4 degrees would be a bad thing but we can still limit the change to 2 degrees C.
[Well we certainly can if we want to. Whether we have the will to do so or not, and whether we should have, is quite another matter -W]
My question was, do you and/or Eli believe Anderson is lying about or is ignorant of the views of the people he views as his "climate change colleagues"? When Bob Watson tells the Guardian it is not now possible to achieve 2 degrees C has he lost touch with reality?
[I don't speak for Eli, obviously. And I don't know who Anderson's colleagues are -W]
I'm wondering about the derision apparent in Eli's comment ("everyone you know is running and screaming and crying") and your confident assertions such as "physically its pretty hard to get disaster out of even +4 oC".
[Perhaps you've misunderstood me. By saying "physically" there I mean in terms of raw temperature, or sea level rise, and so on. As distinct from the ecosystem response which could be disastrous, but I wouldn't know -W]
The difference between an ice age and an interglacial is about 4 degrees C. I was born in Canada. Most of the country was covered in a one mile thick ice sheet, now it isn't. Warming the planet is going to have different effects, but they will be as dramatic. I don't see how the projected 9 billion people are going peacefully work out the problems associated with wholesale global climate change, given that most of them live where the present global climate makes it favorable for humans to live.
["most of them live where the present global climate makes it favorable for humans to live" is quite revealing, when you think about it. Obviously, that spans a range of temperatures far higher than 4 oC. I think it quite likely that people - certainly in the rich world, likely in the poor world - can adapt to the physical effects of +2 oC, maybe +4, what do I know, adaption isn't my field. And since most of the CO2 scenarios depend on the poor world becoming rich in order to generate enough CO2, likely the poor world can, too. Again, this is in physical terms -W]
Eli is with Richard Alley over there in the corner. Eli is also outta here before the stuff hits the fan, so he only has a rooting interest.
" I have a strong feeling that MIT use a rather cut-down model, though."
Certainly true. Of course, given the uncertainties in climate sensitivity, if all you care about is global mean temperature, I'm not sure you need a very sophisticated model - heck, even MAGICC would do for some purposes. Though getting the ocean right might be important, since circulation changes can have some feedbacks on both carbon and heat uptake that might rise to the level of significance where it might matter whether it is included properly... some ecosystem feedbacks might matter too... actually, while MIT's model is relatively simple on the atmospheric side (the one they used for the gambling wheels was a 2D model based on latitude bands) it has some sophistication in the ecosystem and ocean components.
Of course, if you want to look at regional changes you'd definitely want a more sophisticated model. But there, again, I'd prefer an ensemble of simpler models over one single highly sophisticated AOGCM...
Personally, I think that 4 degrees C is pretty likely in the absence of getting serious about climate change. Of course, one might argue that if it was obvious that we were heading there, we'd get serious. Regarding impacts: I agree, it wouldn't be the end of civilization, but I'd guess that we'd see a lot of expensive adaptation in coastal communities, in communities near the expanding Hadley cell belts, in communities with increased flooding, in communities built on permafrost, and for air conditioning, especially in the tropical belts depending on how well the tropical thermostat works. We'd save some money on heating, and some real estate barons who are lucky enough to own land where the climate improves (for whatever purpose) will probably make out like bandits. I agree that ecosystems is where the big impacts are likely at, and I think we'll see invasive species making big gains and diversity suffering losses... and coral especially getting hit... and there being some low possibility of nasty tipping points like Amazonian deforestation or large atmospheric circulation changes.
ps. Regarding Weitzmann: I think he would have been on firmer ground if he'd used a pdf of the damage function rather than of the climate sensitivity. A climate sensitivity greater than 10 is pretty much out of the picture, but the upper bound of the damage function is, in my opinion, collapse of human civilization. Highly, highly unlikely, but with nearly infinite valuation. (Your argument about the destruction of civilization having a finite value does not take into account that the discount rate should actually be a function of the growth of the economy, so if the future economy shrinks, the discount rate can go negative... the argument against an infinite negative discount rate in for a civilization collapse is that there is more than one way for civilization to end, and if the world is going to end in nuclear war in 2100 you don't care that you've committed it to climate death in 2150, and I think that the maths work such that that eliminates the use of an infinite negative discount rate) (mind you, one of the ways for climate change to cause a disaster is if it triggers a nuclear war. Again, highly highly unlikely, but not out of the realm of thinkability).
[I'm still not comfortable with the infinite-value stuff. It may simply be pointing out that I don't understand what they mean by value, though. Or perhaps that pushing these ideas all the way to total destruction produces meaningless results -W]
ALL the evidence says that 20th century warming was caused by the 80 yr "grand maximum" of solar activity that ended in 2000, and since the sun went quiet, warming has stopped. The danger going forward is not warming but cooling, and I'm sorry but there is no excuse for not knowing it.
[Err, no, all your stuff is wrong. I notice you don't even bother provide any references, so sure are you of your nonsense. You need to try reading some of the research on this subject, such as http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9.html. You also need to read the comment policy. I've even clarified it, just for you -W]
Dozens of studies have found a .4 to .7 degree of correlation between solar activity and various climate indices. That is, solar activity "explains" in the statistical sense, 40-70% of past temperature variation. In contrast, there is no such evidence for CO2 having any significant effect.
We know that CO2 does have a small forcing effect, but feedback effects could either amplify or reduce that effect, and there is no reason to think that CO2 after feedbacks has much effect at all. CO2 is correlated with temperature, but lagging 800 years behind, showing clearly that temperature drives CO2. It's not impossible that CO2 is also a significant driver of temperature, but no such signal is discernable in the paleo records. That is in contrast to solar activity, where the signal jumps out like a neon sign.
The ONLY "evidence" in support for the CO2-warming theory is that models driven by CO2 can be tweaked to achieve a reasonable fit with the last 150 years of temperature history. Just dial the climate sensitivity to the moon. But this is really negative evidence, demonstrating that the CO2 theory is not necessarily ruled out. If you crank the climate sensitivity way up you can kinda sorta achieve a half-way plausible fit to the temperature record.
Of course you could do the same with a solar-driven model as well, incorporating one of the hypothesized mechanisms by which solar activity would affect the amount of cloud cover (either GCR-cloud, or the effects of uv-shift on atmospheric circulation, or effects via the earth's electrical circuit). Not only could such a model easily be tweaked to achieve a reasonable fit with 20th century warming, but unlike the CO2 theory, it would also explain why temperatures stopped going up when the 20th century's 80 year "grand maximum" of solar activity ended. But guess what? The "consensus" scientists have never done GCM test runs on the enhanced solar hypothesis.
$100b in public funding and they have never tested the alternate hypothesis. Why? Because they know that the fits would blow their ludicrous CO2-driven models out of the water. They don't want to know the truth, and they don't want anyone else to know the truth. Look at the quote in the post:
"Probabilities of warming projections are based on the approach of (Meinshausen et al. 2011), which involves running a climate model ensemble of 600 realizations for each emissions scenario. In the simulations each ensemble member is driven by a different set of climate-model parameters that define the climate-system response, including parameters determining climate sensitivity, carbon cycle characteristics, and many others."
"Many others" does NOT include any testing of the hypothesis of enhanced solar forcing. They look at a slight range of estimates for TSI (Total Solar Irradiance), but never consider any solar forcing effects beyond TSI.
ALL the data says we should be looking at enhanced solar effects, yet the ONLY model tests they run are CO2 driven. It's the most glaring scientific fraud. In the absence of direct evidence for CO2 warming they introduce this new concept of evidence: model fitting. Then they refuse to apply it to the one hypothesis that is pointed to by the direct evidence.
And so what about you people, who let yourself be duped by such a blatant fraud? Yes, well paid propgandists like the Potsdam Institute are working hard to mislead you, but plenty of other people are trying to tell you the truth. The only way you don't know the truth is if you are intentionally blocking it out. Stop being willfully blind, or in the end you are as bad as the fraudsters.
On the basis of pure scientific fraud they are out to unplug the energy infrastructure of the modern world. It is most nihilistically insane thing to ever happen in the history of mankind. And you people sit here feeling morally elevated as you go along with it, and advocate for it. Come on, it is long past time to wake up.
The bad news (or is it good news?) is that we still don't know very much about climate feedbacks and forcings, hence any prediction of global temps 90 years from now is dubious. The good news (or is it bad news?) is that even if we DID possess such knowledge and formulated a plan to reduce CO2 emissions, the economic cost of such a plan would be prohibitive (not to mention the certain recalcitrance of China and India). Besides, Edmonton and Moose Jaw will be lovely vacation spots.
Well, given sufficient planning and cooperation, the physical changes can get pretty bad without resulting in large-scale death, but based on past experience those are qualities we seem unlikely to deploy at the needed scale early enough.
I agree that the worst effects will be from ecological changes, and I think the science is pointing at some very negative impacts at an early stage.
I just happened to see this new SEI report, which appears to be on point although I haven't read it yet.
You could just burrow Alec Rawls's post and provide a link to his informative website.
Pretty much everything he said in his post was said on his website in 2005. Slow learner ...
[Its like TimeCube, only less interesting -W]
I wonder why none of these projections talk about political unrest. Pakistan has lost 2 of its last 3 years of agricultural production to flood and had its most recent harvest crippled by drought. Were it simply a question of humanitarian concern, it would be serious enough, but Pakistan has a large, militant Islamist faction. And nuclear weapons. And a history of very bad relations with India. Which also has nuclear weapons.
To me, droughts are the most serious outcomes of AGW with floods following close behind. Storms and rising sea levels are crumbs from the table after these. Droughts don't merely reduce farm production: they starve people into motion and political unrest.
We're currently at ~1C of warming. If the last few years of disturbance are any indication of the consequences, we don't want 1.5C much less 2C.
Another great quote about Texas, this time from irish-American General Philip Sheridan, who led an Army of Occupation there after the Civil War:
"If I owned Hell and Texas, I 'd live in Hell and rent out Texas"
An article pointing out that the author doesn't know more about climate science than his commenters.
> .... can adapt to the physical effects of +2 oC, maybe +4,
> what do I know, adaption isn't my field.
Yep. As someone enjoying +80 C with some regularity, I must agree. But of course it only starts with the physics...
Wadda u mean don't mess with Texas, Eli bought the damn thing in the S&L bailout.
Well it could get worse before it gets better.... http://www.unep.org/NewsCentre/default.aspx?DocumentID=2698&ArticleID=9…
A 4 oC world in 2100 is totally unrealistic: Now it's something like 15 oC globally. When exactly during the 21st century should the temperature increase of 4oC happen? During the last 10 years of the century from 2090 to 2100 when we are all dead and will not be able to verify the model promises?
[You're certainly living up to your name. Your question makes no sense; prehaps you could try looking at the graph I've so helpfully included? -W]
WMC writes: Perhaps "…Texas becomes uninhabitable for weather reasons not cultural ones…" is enough to tempt you?
Argh. Yes, it was enough to tempt me, so I clicked through to the article hoping to read about some new and exciting study that had just shown that under BAU scenarios Texas could become uninhabitable by 2050 or something. Alas, all I found was a lot of blather about carbon taxes that happened to contain the quoted phrase as a flippant aside.
As a Yankee and lifelong loather of all things Texified, if the linked article had been what you teased us with, I'd probably have done an about-face on global warming and started looking around for more coal to burn.
To quote General Sheridan, "If I owned Texas and Hell, I would rent Texas and live in Hell".