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IPCC errors: facts and spin

Filed under: — group @ 14 February 2010 - (Czech) (Svenska)

Currently, a few errors –and supposed errors– in the last IPCC report (“AR4”) are making the media rounds – together with a lot of distortion and professional spin by parties interested in discrediting climate science.  Time for us to sort the wheat from the chaff: which of these putative errors are real, and which not? And what does it all mean, for the IPCC in particular, and for climate science more broadly?

Let’s start with a few basic facts about the IPCC.  The IPCC is not, as many people seem to think, a large organization. In fact, it has only 10 full-time staff in its secretariat at the World Meteorological Organization in Geneva, plus a few staff in four technical support units that help the chairs of the three IPCC working groups and the national greenhouse gas inventories group. The actual work of the IPCC is done by unpaid volunteers – thousands of scientists at universities and research institutes around the world who contribute as authors or reviewers to the completion of the IPCC reports. A large fraction of the relevant scientific community is thus involved in the effort.  The three working groups are:

Working Group 1 (WG1), which deals with the physical climate science basis, as assessed by the climatologists, including several of the Realclimate authors.

Working Group 2 (WG2), which deals with impacts of climate change on society and ecosystems, as assessed by social scientists, ecologists, etc.

Working Group 3 (WG3) , which deals with mitigation options for limiting global warming, as assessed by energy experts, economists, etc.

Assessment reports are published every six or seven years and writing them takes about three years. Each working group publishes one of the three volumes of each assessment. The focus of the recent allegations is the Fourth Assessment Report (AR4), which was published in 2007.  Its three volumes are almost a thousand pages each, in small print. They were written by over 450 lead authors and 800 contributing authors; most were not previous IPCC authors. There are three stages of review involving more than 2,500 expert reviewers who collectively submitted 90,000 review comments on the drafts. These, together with the authors’ responses to them, are all in the public record (see here and here for WG1 and WG2 respectively).

Errors in the IPCC Fourth Assessment Report (AR4)

As far as we’re aware, so far only one–or at most two–legitimate errors have been found in the AR4:

Himalayan glaciers: In a regional chapter on Asia in Volume 2, written by authors from the region, it was erroneously stated that 80% of Himalayan glacier area would very likely be gone by 2035. This is of course not the proper IPCC projection of future glacier decline, which is found in Volume 1 of the report. There we find a 45-page, perfectly valid chapter on glaciers, snow and ice (Chapter 4), with the authors including leading glacier experts (such as our colleague Georg Kaser from Austria, who first discovered the Himalaya error in the WG2 report).  There are also several pages on future glacier decline in Chapter 10 (“Global Climate Projections”), where the proper projections are used e.g. to estimate future sea level rise. So the problem here is not that the IPCC’s glacier experts made an incorrect prediction. The problem is that a WG2 chapter, instead of relying on the proper IPCC projections from their WG1 colleagues, cited an unreliable outside source in one place. Fixing this error involves deleting two sentences on page 493 of the WG2 report.

Sea level in the Netherlands: The WG2 report states that “The Netherlands is an example of a country highly susceptible to both sea-level rise and river flooding because 55% of its territory is below sea level”. This sentence was provided by a Dutch government agency – the Netherlands Environmental Assessment Agency, which has now published a correction stating that the sentence should have read “55 per cent of the Netherlands is at risk of flooding; 26 per cent of the country is below sea level, and 29 per cent is susceptible to river flooding”. It surely will go down as one of the more ironic episodes in its history when the Dutch parliament last Monday derided the IPCC, in a heated debate, for printing information provided by … the Dutch government. In addition, the IPCC notes that there are several definitions of the area below sea level. The Dutch Ministry of Transport uses the figure 60% (below high water level during storms), while others use 30% (below mean sea level). Needless to say, the actual number mentioned in the report has no bearing on any IPCC conclusions and has nothing to do with climate science, and it is questionable whether it should even be counted as an IPCC error.

Some other issues

African crop yields: The IPCC Synthesis Report states: “By 2020, in some countries, yields from rain-fed agriculture could be reduced by up to 50%.” This is properly referenced back to chapter 9.4 of WG2, which says: “In other countries, additional risks that could be exacerbated by climate change include greater erosion, deficiencies in yields from rain-fed agriculture of up to 50% during the 2000-2020 period, and reductions in crop growth period (Agoumi, 2003).”  The Agoumi reference is correct and reported correctly. The Sunday Times, in an article by Jonathan Leake, labels this issue “Africagate” – the main criticism being that Agoumi (2003) is not a peer-reviewed study (see below for our comments on “gray” literature), but a report from the International Institute for Sustainable Development and the Climate Change Knowledge Network, funded by the US Agency for International Development. The report, written by Morroccan climate expert Professor Ali Agoumi, is a summary of technical studies and research conducted to inform Initial National Communications from three countries (Morocco, Algeria and Tunisia) to the United Nations Framework Convention on Climate Change, and is a perfectly legitimate IPCC reference.

It is noteworthy that chapter 9.4 continues with “However, there is the possibility that adaptation could reduce these negative effects (Benhin, 2006).”  Some examples thereof follow, and then it states: “However, not all changes in climate and climate variability will be negative, as agriculture and the growing seasons in certain areas (for example, parts of the Ethiopian highlands and parts of southern Africa such as Mozambique), may lengthen under climate change, due to a combination of increased temperature and rainfall changes (Thornton et al., 2006). Mild climate scenarios project further benefits across African croplands for irrigated and, especially, dryland farms.” (Incidentally, the Benhin and Thornton references are also “gray”, but nobody has complained about them. Could there be double standards amongst the IPCC’s critics?)

Chapter 9.4 to us sounds like a balanced discussion of potential risks and benefits, based on the evidence available at the time–hardly the stuff for shrill “Africagate!” cries. If the IPCC can be criticized here, it is that in condensing these results for its Synthesis Report, important nuance and qualification were lost – especially the point that the risk of drought (defined as a 50% downturn in rainfall) “could be exacerbated by climate change”, as chapter 9.4 wrote – rather than being outright caused by climate change.

Trends in disaster losses: Jonathan Leake (again) in The Sunday Times accused the IPCC of wrongly linking global warming to natural disasters. The IPCC in a statement points out errors in Leake’s “misleading and baseless story”, and maintains that the IPCC provided “a balanced treatment of a complicated and important issue”. While we agree with the IPCC here, WG2 did include a debatable graph provided by Robert Muir-Wood (although not in the main report but only as Supplementary Material). It cited a paper by Muir-Wood as its source although that paper doesn’t include the graph, only the analysis that it is based on. Muir-Wood himself has gone on record to say that the IPCC has fairly represented his research findings and that it was appropriate to include them in the report. In our view there is no IPCC error here; at best there is a difference of opinion. Obviously, not every scientist will always agree with assessments made by the IPCC author teams.

Amazon forest dieback: Leake (yet again), with “research” by skeptic Richard North, has also promoted “Amazongate” with a story regarding a WG2 statement on the future of Amazonian forests under a drying climate.  The contested IPCC statement reads: “Up to 40% of the Amazonian forests could react drastically to even a slight reduction in precipitation; this means that the tropical vegetation, hydrology and climate system in South America could change very rapidly to another steady state, not necessarily producing gradual changes between the current and the future situation (Rowell and Moore, 2000).”  Leake’s problem is with the Rowell and Moore reference, a WWF report.

The roots of the story are in two blog pieces by North, in which he first claims that the IPCC assertions attributed to the WWF report are not actually in that report. Since this claim was immediately shown to be false,  North then argued that the WWF report’s basis for their statement (a 1999 Nature article by Nepstad et al.) dealt only with the effects of logging and fire –not drought– on Amazonian forests. To these various claims Nepstad has now responded, noting that the IPCC statement is in fact correct. The only issue is that the IPCC cited the WWF report rather than the underlying peer-reviewed papers by Nepstad et al. These studies actually provide the  basis for the IPCC’s estimate on Amazonian sensitivity to drought. Investigations of the correspondence between Leake, scientists, and a BBC reporter (see here and here and here) show that Leake ignored or misrepresented explanatory information given to him by Nepstad and another expert, Simon Lewis, and published his incorrect story anyway. This “issue” is thus completely without merit.

Gray literature: The IPCC cites 18,000 references in the AR4; the vast majority of these are peer-reviewed scientific journal papers. The IPCC maintains a clear guideline on the responsible use of so-called “gray” literature, which are typically reports by other organizations or governments. Especially for Working Groups 2 and 3 (but in some cases also for 1) it is indispensable to use gray sources, since many valuable data are published in them: reports by government statistics offices, the International Energy Agency, World Bank, UNEP and so on. This is particularly true when it comes to regional impacts in the least developed countries, where knowledgeable local experts exist who have little chance, or impetus, to publish in international science journals.

Reports by non-governmental organizations like the WWF can be used (as in the Himalaya glacier and Amazon forest cases) but any information from them needs to be carefully checked (this guideline was not followed in the former case). After all, the role of the IPCC is to assess information, not just compile anything it finds.  Assessment involves a level of critical judgment, double-checking, weighing supporting and conflicting pieces of evidence, and a critical appreciation of the methodology used to obtain the results. That is why leading researchers need to write the assessment reports – rather than say, hiring graduate students to compile a comprehensive literature review.

Media distortions

To those familiar with the science and the IPCC’s work, the current media discussion is in large part simply absurd and surreal. Journalists who have never even peeked into the IPCC report are now outraged that one wrong number appears on page 493 of Volume 2. We’ve met TV teams coming to film a report on the IPCC reports’ errors, who were astonished when they held one of the heavy volumes in hand, having never even seen it. They told us frankly that they had no way to make their own judgment; they could only report what they were being told about it. And there are well-organized lobby forces with proper PR skills that make sure these journalists are being told the “right” story. That explains why some media stories about what is supposedly said in the IPCC reports can easily be falsified simply by opening the report and reading. Unfortunately, as a broad-based volunteer effort with only minimal organizational structure the IPCC is not in a good position to rapidly counter misinformation.

One near-universal meme of the media stories on the Himalaya mistake was that this was “one of the most central predictions of the IPCC” – apparently in order to make the error look more serious than it was.  However, this prediction does not appear in any of the IPCC Summaries for Policy Makers, nor in the Synthesis Report (which at least partly explains why it went unnoticed for years). None of the media reports that we saw properly explained that Volume 1 (which is where projections of physical climate changes belong) has an extensive and entirely valid discussion of glacier loss.

What apparently has happened is that interested quarters, after the Himalyan glacier story broke, have sifted through the IPCC volumes with a fine-toothed comb, hoping to find more embarrassing errors. They have actually found precious little, but the little they did find was promptly hyped into Seagate, Africagate, Amazongate and so on. This has some similarity to the CRU email theft, where precious little was discovered from among thousands of emails, but a few sentences were plucked out of context, deliberately misinterpreted (like “hide the decline”) and then hyped into “Climategate”.

As lucidly analysed by Tim Holmes, there appear to be a few active leaders of this misinformation parade in the media. Jonathan Leake is carrying the ball on this, but his stories contain multiple errors, misrepresentations and misquotes. There also is a sizeable contingent of me-too journalism that is simply repeating the stories but not taking the time to form a well-founded view on the topics. Typically they report on various “allegations”, such as these  against the IPCC, similar to reporting that the CRU email hack lead to “allegations of data manipulation”. Technically it isn’t even wrong that there were such allegations. But isn’t it the responsibility of the media to actually investigate whether allegations have any merit before they decide to repeat them?

Leake incidentally attacked the scientific work of one of us (Stefan) in a Sunday Times article in January. This article was rather biased and contained some factual errors that Stefan asked to be corrected. He has received no response, nor was any correction made. Two British scientists quoted by Leake – Jonathan Gregory and Simon Holgate – independently wrote to Stefan after the article appeared to say they had been badly misquoted. One of them wrote that the experience with Leake had made him “reluctant to speak to any journalist about any subject at all”.

Does the IPCC need to change?

The IPCC has done a very good job so far, but certainly there is room for improvement. The review procedures could be organized better, for example. Until now, anyone has been allowed to review any part of the IPCC drafts they liked, but there was no coordination in the sense that say, a glacier expert was specifically assigned to double-check parts of the WG2 chapter on Asia. Such a practice would likely have caught the Himalayan glacier mistake. Another problem has been that reports of all three working groups had to be completed nearly at the same time, making it hard for WG2 to properly base their discussions on the conclusions and projections from WG1. This has already been improved on for the AR5, for which the WG2 report can be completed six months after the WG1 report.

Also, these errors revealed that the IPCC had no mechanism to publish errata. Since a few errors will inevitably turn up in a 2800-page report, obviously an avenue is needed to publish errata as soon as errors are identified.

Is climate science sound?

In some media reports the impression has been given that even the fundamental results of climate change science are now in question, such as whether humans are in fact changing the climate, causing glacier melt, sea level rise and so on. The IPCC does not carry out primary research, and hence any mistakes in the IPCC reports do not imply that any climate research itself is wrong. A reference to a poor report or an editorial lapse by IPCC authors obviously does not undermine climate science. Doubting basic results of climate science based on the recent claims against the IPCC is particularly ironic since none of the real or supposed errors being discussed are even in the Working Group 1 report, where the climate science basis is laid out.

To be fair to our colleagues from WG2 and WG3, climate scientists do have a much simpler task. The system we study is ruled by the well-known laws of physics, there is plenty of hard data and peer-reviewed studies, and the science is relatively mature. The greenhouse effect was discovered in 1824 by Fourier, the heat trapping properties of CO2 and other gases were first measured by Tyndall in 1859, the climate sensitivity to CO2 was first computed in 1896 by Arrhenius, and by the 1950s the scientific foundations were pretty much understood.

Do the above issues suggest “politicized science”, deliberate deceptions or a tendency towards alarmism on the part of IPCC? We do not think there is any factual basis for such allegations. To the contrary, large groups of (inherently cautious) scientists attempting to reach a consensus in a societally important collaborative document is a prescription for reaching generally “conservative” conclusions. And indeed, before the recent media flash broke out, the real discussion amongst experts was about the AR4 having underestimated, not exaggerated, certain aspects of climate change. These include such important topics as sea level rise and sea ice decline (see the sea ice and sea level chapters of the Copenhagen Diagnosis), where the data show that things are changing faster than the IPCC expected.

Overall then, the IPCC assessment reports reflect the state of scientific knowledge very well. There have been a few isolated errors, and these have been acknowledged and corrected. What is seriously amiss is something else: the public perception of the IPCC, and of climate science in general, has been massively distorted by the recent media storm. All of these various “gates” – Climategate, Amazongate, Seagate, Africagate, etc., do not represent scandals of the IPCC or of climate science. Rather, they are the embarrassing battle-cries of a media scandal, in which a few journalists have misled the public with grossly overblown or entirely fabricated pseudogates, and many others have naively and willingly followed along without seeing through the scam. It is not up to us as climate scientists to clear up this mess – it is up to the media world itself to put this right again, e.g. by publishing proper analysis pieces like the one of Tim Holmes and by issuing formal corrections of their mistaken reporting. We will follow with great interest whether the media world has the professional and moral integrity to correct its own errors.

PS. A new book by Realclimate-authors David Archer and Stefan Rahmstorf critically discussing the main findings of the AR4 (all three volumes) is just out: The Climate Crisis. None of the real or alleged errors are in this book, since none of those contentious statements plucked from the thousands of pages appeared to be “main findings” that needed to be discussed in a 250-page summary.

PPS. Same thing for Mike’s book Dire Predictions: Understanding Global Warming, which bills itself as “The illustrated guide to the findings of the IPCC”. Or Gavin’s “Climate Change: Picturing the Science” – which does include a few pictures of disappearing glaciers though!

Update 24 March: Simon Lewis has made an official complaint to the Press Complaints Commission about Leake’s Amazon story.

Update 29 March: IPCC Chairman Rajendra Pachauri has published an interesting article in the Guardian.

601 Responses to “IPCC errors: facts and spin”

  1. 401
    Completely Fed Up says:

    jonesy says:
    16 February 2010 at 4:33 PM

    Re: #384 Completely Fed Up said: “Name ONE ERROR on that table, jonesy.”

    The rate for the Pindari Glacier is wrong.”

    Uh, no, that error doesn’t appear in table 10.9.

    Check for yourself:

    Seek for WG2 as you required.

    Check around chapter 10, section 5.7

  2. 402
    rainwater says:

    mmmm I am currently doing an assessment of the impacts of climate change on a large cities infrastructure as I am reading this. I would argue there are many with vested interests in “AGW” such as my employer, who without it would not currently be getting $ for me doing this study! – to claim there are none with vested interests is incredibly foolish.

    There are people on boths sides with interests! If I owned a hydrolake I would want to put coal out of business etc…if I owned a coal powered fire station I would not want AGW to be happening – lets just be open and honest for once, there are many vested interests in AGW, and AGW gets a LOT more funding than any sceptical research. This is not a conspiracy, its a fact of life!

    Also, pointing that Exxon etc.. fund sceptical science is odd when they also fund alot of climate science. I recall in the climategate emails there were emails talking about getting funding from Exxon and Shell – so seems IPCC climate scientists do not mind being funded by “big oil” either. Fact is, if you need funding you go to those that will fund it. Their agenda / interests will determine whether or not you get the funding.

    On the IPCC errors, we are only human, errors happen lets not give them a hard time. If no one ever found an error in any of my work I would be very suprised!

  3. 403
    Don Shor says:

    389 Doug Bostrom:
    “– The first “widespread” media mention of the Himalayan business appears around December 5, 2009.”

    Again, Drs. Pachauri and Hasnain had information in 2006 that their claim about the glaciers melting by 2035 was not supported by leading glaciologists.
    Do you believe Dr. Hasnain was unaware that his claim had been rejected by others in his field?
    Nevertheless, they continued to use it as they sought funds for their company.
    Again, Doug, what do you call that behavior?

  4. 404
    Don Shor says:

    I wrote [15 February 2010 at 11:56 PM]: I think it is safe to assume that the president of TERI was involved in negotiating for the contracts.
    Doug Bostrom replied: 16 February 2010 at 2:41 AM
    Don Shor says:
    “I think it is safe to assume…”
    Is it? How much elasticity is there in safe assumptions, particularly when they involve character assassination?

    You’re right. The president of the company might have had no involvement in negotiating contracts worth hundreds of thousands of dollars to his company. But that seems very unlikely, doesn’t it?

  5. 405
    JRC says:

    First time posting here, but enjoy reading the comments.

    I was thinking about the models, and this might be a stupid question, but I’ve been told the only stupid question is the one not asked.

    I feel I have a decent understanding of the energy budget from the sun. I was wondering if there was also energy budget created by humans, or if it is too small to be a contributing factor?

    To be specific, not only does the burning of fossil fuels release CO2, but heat as well. If the average automobile engine heats up to 200 degrees F and you have 100’s of million of automobiles is that a significant amount of heat being released as well as CO2?

    I thought might ask here first before making a major project out of it because there are so many intelligent posters here.

    Thank you.

  6. 406
    John Monro says:

    Nothing to add climate-wise really, just a note of thanks for yet another wonderful article. But it dismaying that you had to write it in the first place. I hate to say this, but eventually this battle between enlightenment and denial will become more tangible in society, if we are going to survive. I include such things as civil disobience, nonviolent protest and more overt political action becoming the norm, perhaps tied in to the pressing environmental / economic problems such as oil depletion and monetary collapse. It is difficult at this time to see which of these will be the most urgent or the most dire. Either way, I see the first part of this new century rapidly becoming very stormy for us all, literally and metaphorically.

  7. 407
    robert says:


    #187 robert says:
    15 February 2010 at 12:36 PM
    Please help me understand the timing of glacier retreat. It probably has been addressed somewhere but I cannot find.
    During last glacier advance(approx 20K years ago) glaciers in the US reached down to about NYC(40 degees north) in some parts. When the Spanish were exploring in the 1500’s they were able to sail (ice free) to about Baffin Island the southern part of which is about 60 degrees north. This represents a 20 degree retreat or about 1200 miles. Taking some numbers from the Himalayan Glaciers of 100 meter retreat per year a 20 degree retreat would take about 18K years. So what is so unusual about the current glacier retreat?
    I realize above is comparing different geographies but I would like to get a handle on any acceleration of the normal rate of glacier retreat.

  8. 408
    Nick Xylas says:

    Sadly, the drip-drip of propaganda seems to be having the desired effect, if this Rasmussen poll is to be believed.

  9. 409
    Tim Jones says:

    Re: 392 Doug Bostrom says: 16 February 2010 at 4:50 PM
    “It’s all about whether C02 is or is not a pollutant.”

    Skeptic’s claims that CO2 is good fertilizer should be furthered to illustrate that CO2 is just like poop. In goes food, out goes you know what.

    In goes O2, out goes CO2. Both poop and CO2 are waste products of animal metabolism.

    Ignorant people that claim CO2 is harmless need to put a plastic bag over their head for a few minutes. Long before one passes out from a lack of oxygen one passes out from CO2 poisoning. When the CO2 concentration becomes about 7% to 10% of your amb-ient air you’re a goner, even if the rest of the air is O2. It’s called CO2 narcosis and it’s deadly.

    CO2 is essential to life, but CO2 is not a harmless gas.

    Like with many things CO2 becomes a pollutant when the concentration gets too high. Examples like the eruptive overturning of Lake Nyos in Cameroon point to how deadly dangerous high concentrations of CO2 really are to all forms of animal life.

    In the atmosphere at much lower concentrations CO2 has to do with elevating warming past what the planet’s life has adapted to or can cope with.

    DB: “If fossil fuel interests lose this battle, it’s a huge defeat for them, they could lose the war.”

    So could we. It will surely go to the Supreme Court. It will be interesting how it rules, if it chooses to do so. I think the right wing has been tilting the playing field to their advantage for quite some time now.

  10. 410
    David Horton says:

    #386 “while Sun is obviously – OBVIOUSLY – one of the main reasons behind climate fluctuations. That is your flat earth argument.” Um, yes, it certainly is!

  11. 411
    Ray Ladbury says:

    Andreas, care to point out an example where science did not correct itself when it started down a rabbithole? Thought not. Are you familiar with the British slang term “wanker”?

  12. 412
    jonesy says:

    Re #401 Completely Fed Up said,
    “Uh, no, that error doesn’t appear in table 10.9.

    Check for yourself:

    Seek for WG2 as you required.

    Check around chapter 10, section 5.7

    Dude, you sound like a contrarian mole trying to make the AGW position look foolish.

    Table 10.9 is on page 494 of Chapter 10. You can see that page in the very same pdf link for Chapter 10 provided in the OP for page 493.

    I again suggest reading Anatomy of IPCC’s Mistake on Himalayan Glaciers and Year 2035 for understanding what happened.

  13. 413
    Didactylos says:

    CFU: I’m looking at figure 10.9, and I see Pindari Glacier (Uttaranchal) 1845 to 1966 2,840 135.2

    Clearly a simple (and inconsequential) error carried over from the source material.

    Are you confused by the numbering scheme? Tables are numbered sequentially through the whole chapter, and are not necessarily presented in order.

    CFU, this isn’t a race to see how many errors we can make. Slow down, and check things before you post. Lambast deniers for what they get wrong, but don’t automatically assume they are wrong.

    Post in haste, regret at leisure, as they say.

  14. 414
    Doug Bostrom says:

    Don Shor says: 16 February 2010 at 6:55 PM

    Don, I don’t give a jot one way or the other about Pachauri or Hasnain’s behavior, not with regard to my beef on this matter.

    My interest lies in how Roger Pielke Jr. feels free to level accusations of scientific sloppiness against whomever he selectively chooses, is quite prepared to deliver tendentious lectures on proper behavior, yet does not hew to the standards he himself espouses.

    Here, again, is Pielke’s specific claim:

    IPCC Chairman Pachauri was making public comments on a dispute involving factual claims by the IPCC at the same time that he was negotiating for funding to his home institution justified by those very same claims.

    Pielke offers no evidence for this, only conjecture. Yet Pielke finds no inhibition against criticizing others for the same fault.

    If Pielke’s not to appear hypocritical, he needs to either produce some support for his accusation, or make it vanish.

    Hint: Pielke’s going to have a -very- hard time proving his imagined chronology, as bothering to spend five minutes’ time on research shows.

  15. 415
    dhogaza says:

    JRC asked:

    I was thinking about the models, and this might be a stupid question, but I’ve been told the only stupid question is the one not asked.

    To be specific, not only does the burning of fossil fuels release CO2, but heat as well. If the average automobile engine heats up to 200 degrees F and you have 100’s of million of automobiles is that a significant amount of heat being released as well as CO2?

    If it were stupid, researchers wouldn’t look into it … however … researchers have, being “leave no stone unturned” type people. BTW it’s not just the burning of fossil fuels but energy dissipated as heat due to friction, etc.

    <a href=" A bit of googling returns a paper that gives these figures for 2005 and future projections:

    2005 global-mean AHF: 0.03 W/m2

    2040 global-mean AHF: 0.06 W/m2

    2100 global-mean AHF: 0.19 W/m2

    Compare this with the radiative forcing that results from a doubling of CO2 (without considering feedbacks):

    4 W/m2

    However, over land, in densely populated areas like the Netherlands, direct heat contribution can be much higher than the global average, in fact the paper I linked above references a paper from The Netherlands that computes the direct heat contribution to be 4.2 W/m2!

    But it’s the global figure that counts regarding the effect on global climate.

  16. 416
    David B. Benson says:

    robert (407) — After the big melt was over about 7,500 years ago, glaciers began to reform as expected from orbital forcing. However, just recently, many glaciers have been retreating. The rate is controlled by a variety of factors which can be studied via several web sites.

    As an amateur at all this, I don’t know how to even begin answering your question about rates except to point out that there are previous threads here on RealClimate concerning estimates for SLR by 2100 CE. As I recall, the estimates range from 0.8 m to an unlikely 2 m. Whatever, this will have serious impacts for the majority of the world’s population.

  17. 417
    Ray Ladbury says:

    Axel, Based on your posts here, you most assuredly do not understand the science. In fact you don’t understand science itself.

    And what is more, you have given no constructive suggestions beyond “ignore the evidence”. Just how do you do science without evidence?

    It comes down to whether human beings as a collective decide to accept physical reality or whether they continue to ignore it. If they accept it soon, I hold out some hope that we could avoid the worst catastrophes of climate change while still maintaining a relatively decent living standard and preserving principles of a market economy and democracy. If we do not accept reality within a few years, it will take draconian measures to avoid catastrophe. And finally, if we do not see the light within 50 years, catastrophe will be unavoidable. The extent of that catastrophe remains to be seen, but I would be surprised if we emerged from it with anything that could be called civilization.

    It is clear that you care nothing for the future of our species. You are too busy selling out. You will excuse me if I find nothing to respect in your attitude.

  18. 418
    Ray Ladbury says:

    JRC, I calculate that the amount of energy humans used in 2008 was less than 0.01% of the solar flux incident on Earth in the same period.

  19. 419
    Hank Roberts says:

    CFU, mark my words, this is where you cheerfully admit you were wrong and thank your fellow readers for catching your mistake. All of us get it wrong sometimes and are lucky when we’re corrected early.

    You know what they used to say about how to find good information on Usenet?
    Post what you think, and await correction.


  20. 420
    noel says:

    @ 371″ We don’t NEED any alternative energy sources. Start reading on the recent developments of shale gas extraction. We have enough of that to last for a few hundred years.
    Comment by noel — 16 February 2010 @ 9:35 AM
    Who are you reading, Winnie the Pooh? Try Shale is not now, and never will be, your savior. Just shifting infrastructure alone is a humongous issue.
    Wake up. Let the info inform your position, not the other way around.
    Comment by ccpo — 16 February 2010 @ 1:18 PM”

    I’m reading eg

    So wait, gas isn’t good because shifting infrastructure would be hard? Are you serious? But moving to wind/solar/divine/green fairy energy wouldn’t require a huge infrastructure shift? If you’ve following Czech news, you’d find out that these alternative sources are a lot harder to integrate: that’s why they are considering cutting off some of the already existing ones from their grid.

  21. 421
    Mark Hadfield says:

    JRC at post 405: “To be specific, not only does the burning of fossil fuels release CO2, but heat as well. If the average automobile engine heats up to 200 degrees F and you have 100’s of million of automobiles is that a significant amount of heat being released as well as CO2?”

    A good question, but the answer, in short, is “No”. This question has come up and been answered on RealClimate before, but right now I can’t remember where.

  22. 422
    flxible says:

    noel – the American Enterprise Institute??? sure they’d love shale gas, the energy giants have invested many billions in it – burning gas is not good because it continues the BAU CO2 production, which is not an issue with them, but should be to you

  23. 423
    flxible says:

    Nick Xylas@408 – seems polls are where you find them, this one and again this one disagree with your American “energy report” pollster, maybe the US is the problem?

  24. 424
    noel says:

    @ 399
    Re:386 Arrogance says: 16 February 2010 at 4:13 PM
    “Exactly why do you have the higher moral ground here?
    Exactly because a growing component of what’s called the 6th extinction is climate change. Climate scientists are bending over backwards to keep the world habitable for you, your children and the rest of biodiversity while you’re wasting everyone’s time trotting out of zombie arguments like “scientists fooled us before” (they didn’t) to fool people into complacency.
    But please do as David Benson and others have suggested. There’s plenty of room on the high ground.
    Comment by Tim Jones — 16 February 2010 @ 5:59 PM

    Seriously? And how exactly are they bending over backwards? How did they precisely DO anything? They’re just telling everyone else that they should give them more money so they can waste on more of these delusions. They haven’t done anything else. They’re doing what’s convenient for them, it’s not like they’re sacrificing their personal life or anything, you know.

    Bending over backwards…lol..

  25. 425
    JRC says:

    Thanks to those that addressed and answered my post. I especially liked the link about AHF. Thanks dhogaza. I should have known that my question had already been addressed by the climate science community. And thanks Ray Ladbury for the calculation, while I’m surprised at it being such a small percentage compared to solar flux at the same time I’m not all that surprised when I really think about it. And thank Mark, I’ll do a search and see if I can locate where it’s been discussed here. I think it would be an interesting read and increase my knowledge on the topic.

  26. 426

    JRC at post 405: “To be specific, not only does the burning of fossil fuels release CO2, but heat as well. If the average automobile engine heats up to 200 degrees F and you have 100’s of million of automobiles is that a significant amount of heat being released as well as CO2?”

    I believe you are referring to “waste heat” or “anthropogenic heat”. This has of course been investigated for quite a while and incorporated into human-caused climate change (or not as the case may be because it is too small to even be factored in at this point).

    It is currently considered a pretty small-to-negligible global warming forcing right now (but much bigger for city areas)…but perhaps eventually with so much energy potentially being produced by the burgenoning human population, that it might eventually become a stonger factor.

    “Global Energy Accumulations and Net Heat Emission” by Bo Nordell and Bruno Gervet, International Journal of Global Warming, Vol. 1, Nos. 1/2/3, 2009, pg. 378.

    “Long-Term Global Heating from Energy Usage” by E. J. Chaisson, EOS, Transactions of the American Geophysical Union, Vol. 89, No. 28, July 8, 2008, pg. 253.

    ATJ de Laat – Eos, 2008 – American Geophysical Union An edited version of this paper was published by AGU. EOS transactions FORUM, Vol.
    89, No. 51, doi: 10.1029/2008EO510005, 16 December 2008. Copyright (2008)

    Flanner, M. G., 2009. “Integrating anthropogenic heat flux with global climate models”. Geophys. Res. Lett.

    Block, A., K. Keuler, and E. Schaller, 2004. “Impacts of anthropogenic heat on regional climate patterns”. Geophys. Res. Lett.

    Intergovernmental Panel on Climate Change, 2007- 130 countries have unanimously voted on the results….while every single word was voted on in the summary for policy makers by 130 countries (which no one has questioned).

  27. 427
    Paul Harris says:

    “The maximumistdistortionism of the deniaistliespinandcynism on IPCC atmostmiminmalist errors” would not be a good heading either.

    There are always going to be differences between the hard climate science written into IPCC reports and the ‘what if’ attempts by non-scientists to forecast possible/probable societal, economic and political impacts of AGW. Because, despite all their pretensions to the contrary, neither economics, nor sociology (which I teach)nor politics are sciences. They might use data, but they are still guesswork.

    What,for example, might be the impact on my society -Aotearoa/New Zealand-
    of the attempted migration here of possibly millions of Pacific Island and South Asian people if AGW contributes to the destruction of the coral reef based ecology/way of life? No one can possibly know, in the way that scientists know that if you jump of a roof the law of gravity applies with no exceptions. Much would depend on the state of our economy at the time, the political leanings of the government in power, and the ethnicity, language skills and work skills of the potential refugees.

    There was once a British TV show called “The Goodies”. You are the goodies and I love you.

    I have a wee baby grandson, I want him to live in a viable world. I don’t like the IPCC’s findings, but I accept the validity of their science. I would rather debate how best we can as human beings and societies cope with what might be coming. That is where the ‘gray’ work should kick in.

  28. 428
    Paul Harris says:

    Sorry, couple of typos there: should read “denialistliespinandcynicism” and one jumps “off” roofs. Many blushes. Forgive.

  29. 429
    Peter Thwaites says:

    I found the article helpful but could not find the names of the authors.

    [Response: ‘group’ posts are signed by all contributors. – gavin ]

  30. 430
    Completely Fed Up says:

    “So wait, gas isn’t good because shifting infrastructure would be hard?”

    No, gas isn’t good because it’ll be expensive in energy to get it out in quantities.

    Gas is by a long chalk the most expensive to run.

    PS why is it you lot only ever “paraphrase” a statement into a strawman? Don’t you have any arguments that stand up to scrutiny?

  31. 431
    Completely Fed Up says:

    Jonesey: “Dude, you sound like a contrarian mole trying to make the AGW position look foolish.

    Table 10.9 is on page 494 of Chapter 10”

    Well lets have a look at what you said earlier:

    jonesy says:
    16 February 2010 at 3:00 PM

    Table 10.9 of WGII also has an error that should be acknowledged.”

    Now, why did you not know what page it was on?

    Did you while reading it not notice that it came after 10.10, thereby indicating what need there is for a page reference?

    Did you also forget what the error was so couldn’t say what the error was?

    How do you think you’d get on if you walked into the police station with someone, pointed to them and said “A crime has been committed. Arrest him!”?

    You’d be thrown out as wasting police time.

    The only reason I can see for keeping that information off the post you made was that at the time you didn’t know it.

    Dude, you’re showing the dittos as being mendacious and parroting sight unseen reports of others without evidence of scepticism.

  32. 432
    Completely Fed Up says:

    “You’re right. The president of the company might have had no involvement in negotiating contracts worth hundreds of thousands of dollars to his company.”

    But can that president go back in time to allow a later event to influence an event earlier in time?

    It’s not impossible, but it’s highly unlikely, isn’t it.

  33. 433
    Harry Hodge says:

    Lets clear the air. Axel is a sceptic. He is also making points about the “marketing” of the the AGW case.

    The Pope believes in God and has dedicated his life to worship and prayer (and there isn’t a God). The Pope has views and influences on other areas of life and just because he is wrong (big time) on the God thing, it doesn’ mean his views on anything else are irrelevant.

    Forget Axel’s position on AGW and listen/respond to what he is saying about the presentational aspects.

    In the same way that RC devotees react to their position being attacked – the sceptics react to their motives being questioned or dismissed as “big oil” everytime. That has been the line and it isn’t working is it?

  34. 434

    The aptly-named “Arrogance” (386): while Sun is obviously – OBVIOUSLY – one of the main reasons behind climate fluctuations. That is your flat earth argument.

    BPL: Percent of variance of temperature anomalies 1880-2008 accounted for by solar variation: 2.5%

    Percent accounted for by CO2: 76%

    Do the friggin’ math, Arrogance.

  35. 435

    JRC — no, the amount of heat from technological combustion and other processes is negligible compared to sunlight and atmospheric back-radiation.

  36. 436
    AxelD says:

    Ray @417, it’s quite obvious that you haven’t really been listening to a word I’ve said. You have me (quite wrongly) marked down as a “denialist” so you’re attributing motives to me that fit you preconceptions. This is really not a great approach for a scientist, if that’s what you claim to be, and makes me wonder to what extent you actually “understand science itself.”

    But I’ll give you the benefit of the doubt anyway, because I’m a reasonable fellow, and very patient.

    I perfectly understand that you’ve got piles and piles of evidence, and that you can’t “do science without evidence.” But what I understand – and you patently don’t – is that there is a huge gap between your understanding of the evidence, and the public’s and government’s.

    Your understanding of the evidence is irrelevant if the decision-makers and the public understand believe something else. This is what’s called realpolitik. It’s a hard fact for you and your cronies at RC to accept, but it’s crucial to you making progress.

    Now I know that you feel that all you have to do is to patiently explain how all the evidence stacks up and, all round the world, jaws will drop, and people will ask “why didn’t we see it before?”

    Things do not work like that. Public opinion about (what is seen as) inaccessible science doesn’t weathercock. You’ve had 15+ years of very favourable (in AGW terms) press reports and political involvement. I know you all complain about evil right-wing media conspiracies and malicious bloggers, but we live in a democracy and, in your heart of hearts, you know that you’ve had a very fair crack of the whip, with a preponderance of favourable reporting.

    But, as I’ve explained above, your brand is broken. That 15+ years of positive coverage is going down the tubes very rapidly unless you do something about it. While you’ll never lose all your supporters (the good old Guardian will still be there) the balance of coverage has already shifted heavily to the other side.

    It won’t necessarily stay there if some incontrovertibly climate-related disaster happens soon. But we all hope that won’t happen, and the public perception of climate change over the last 15 years doesn’t suggest it’s imminent. So, what do you do?

    It pains me to hear you say that I haven’t any constructive suggestions! And I certainly never said “ignore the evidence”! (That’s your bias showing, I’m afraid.) I probably said that the evidence is trumped by public and governmental perceptions, but that is true, and very different from your interpretation.

    So, my constructive suggestions? I’ve told you before, many times, but you won’t listen. You have to rebuild your brand. As Toyota and many other enterprises have found, this is an extremely costly and painful process, but the longer you put it off the more costly and painful it becomes.

    It is essential that the IPCC is seen to be either replaced or radically reorganized. I’m not saying that the evidence in which you place such faith has to be thrown away, but I am saying that it has to be publicly re-appraised by a balanced panel that isn’t tainted by the cosy coterie that has been responsible so far. You may argue with that, but I’m giving you the benefit of a realistic opinion that recognizes the problems you face. It may not be fair, in your view, but I said that it would be costly and painful.

    If, as you believe, the pure truth of your evidence comes shining through, then the whole world (OK, most of it) will be ready to give you a fair hearing. Great! – open and above board, sceptics and advocates alike agree that the world is warming and there will be these explicit consequences within commonly agreed limits with understood degrees of uncertainty.

    You’ll probably say that we should be there now, but we’re patently not, and the reasons are well-known, even if you won’t readily admit to them. I’ve given you a constructive suggestion that should help fix the problem. You seem to have 100% faith in the rightness of your cause – if you won’t at least consider it, what are you afraid of?

    PS It would be appreciated if CFU (for instance, @383) didn’t respond to this post. His extraordinary talents would be far better employed outside of this blog.

  37. 437
    Completely Fed Up says:

    re 405, some back-of-the-envelope stuff:

    the population density of NYState is about 410 people per sq km.

    Average power use per head in the US is 1,460W per person.

    1,000,000 square meters per km means this is 0.6 watts per square m.

    Average insolation: 235 Watts per square meter.


    The US is quite profligate in energy.

    NYState is quite densely populated.

    Ergo, this would be quite an overestimate.

    This increases linearly with population (absent any change per head), whereas the effect of CO2 over the centuries scale is exponential to CO2 output (since each year adds to the year before).

  38. 438
    Andreas Bjurström says:

    @ 411 Ray Ladbury,
    History is the most useful arena for “rabbit hole” discussions (I am not a historian, but I wíll try). In retrospect it is easier to see how science depend on societal viewpoint (and the other way around), and how a culture can get trapped for hundreds of years in rabbit holes. Suddenly they brake loose from their scientific worldview, or they don´t, or gets extinct, or driven out of business. Is this because science is always, all the time, constantly self-correcting? No, it is not. Moreover, we take for granted that a change is progress. Do we really know that is always the case?

    Throughout the middle ages, most science was trapped in the writing of Aristotele. Back then it was the truth, in retrospect it looks like a rabbit hole. All intellectuals in the western world was digging down in the same rabbits hole … And when Galileo Galilei wanted to dig a better hole, he was harassed by science and church …

    We are certainly in a big rabbit hole (I am not speaking mere of climate change now, but more general), the problem is that we do not know yet where the way out is. When the next Galileo Galilei visit us in the rabbit hole, what will we do? If he speaks on climate change, I am afraid that most believers from this blog will be most eager to harass him.
    The sceptics will harass him as well, cause he will not speak from the taken for granted.

    The population bomb, my elderly environmental professors at my department still talks about that being the only important issue, us youngers are stupid cause we do not belong to the right gospel, nothing is better then neo-malthusian science and its political implications (kill them all). There was a scientific concensus on this in the 1960´s. What happpended? Self-correction? Not! Will my professions self-correct? No, but they will soon die. Are they individuals? Yes, but they are thousands of professors in their age around the world that hold exactly the same beliefs and never changed them, they have not moved an inch for the last fourty years, hehe.

    The natural scientists, as always, framed the issue (the population bomb environmental problem), explained that population increased, they constructed quantitative models and scenarious … sounds rather familiar … yet, the important issue was elsewhere, not in the science of the cause to population, but in the ideological assumptions in neomalhusianism, the political concequences, other ways to understand population, other solutions. No, this is not mere politics. To frame science is a science, to acknowledge and change the frame is hard scientific work, often takes a genius to do it. It is time that climate science steps out of the cave and adress the broader picture, physical reductionism is not doing much good. Having said this, I do not believe that climate change will disappear as a problem, like the population bomb did, but I think we will be closer to truth if we do so and that we also will have a much more interesting debate and more and better policy options.

    Since most people at this blog are hard science objective reductionists, and most others are sceptics, I kind of assume to be harassed for this statement, but that is ok. Go on with the gospel and the war with the sceptics in the battle-ground of mere the physical world, that is your game, but not mine …

  39. 439
    Nick Xylas says:

    Fixible@423 – thanks for those other polls, I was beginning to feel quite depressed. The BBC poll says that the US, along with China, is indeed the problem. Trouble is, they’re also the biggest polluters.

  40. 440
    flxible says:

    Axel – You may have a semi-useful point in your Brand-centered focus, but in fact democracy is NOT relevent, rather MONEY is the critacal factor, public opinion affects nothing to do with government until it’s absolutely overwhelming, as in revolution, meanwhile corporate financial “persuasion” pulls the reins. What Toyota “has found” is there’s ups and downs in marketing, and the public is fickle. Give’em a while and most will have forgotten a few crashes, the same as they’ve forgotten about Ford/Firestone roll overs. But climate change isn’t going to be forgetable. It’ll continue to be ever more persuasive than marketing. Most Americans fantasize that they live in a “democracy”, even though it’s in fact a “republic” [for which they stand!!], although there’s little “publica” left in the “res”.

    The IPCC is obviously a political, policy based organization – it was instituted by governments for the purpose of advising on policy for governments to deal with the consequences of global climate change. There will continue to be such an organization in some form, just as there continues to be a UN regardless of the many Americans who have wished it to vanish since it’s inception. And many [especially Americans] will continue to try to shout it down. There are 2 classes of “skeptics”: one just can’t cope with change and denies that humans could be having any effect, the other wants to protect their lucrative livihood, both rail about big government tax ripoffs – the first will never be convinced by PR, the 2nd is actually beginning to understand the time has come to “get on board”, diversify their investments, and hedge their bets, including [especially?] the insurance industry, hence funding of some semi-skeptic semi-professional “policy outcome research”. Change is tough, it won’t be non-violent, as we are already seeing. There will be cannibalism.

  41. 441
    robert says:

    Thanks to David B for a response in #416 to my question in #407.
    The reason I am focusing on the speed of glacier retreat is that it has been advanced, at least in the media, as a marker of GW. If the majority of the retreat took place before 1500 this would seem to take the “A” out of AGW as a cause of the retreat, or at least complicate it. To put the “A” back in would need to see recent acceleration of the speed of retreat over and above the historic norm.

  42. 442
    flxible says:

    Andreas: ” (…)disappear as a problem, like the population bomb did”
    the “population bomb problem” hasn’t disappeared at all Andreas, it may not have wrung out quite the way Erlich wrote it, it’s morphed into the overconsumption problem, the climate-changing CO2 problem, and most every other thing that’s called a “problem” in the world, drastically reduce the population and they’d all dry up

  43. 443
    flxible says:

    Yes Nick, it’s heartening to realize public perceptions aren’t quite as myopic as sometimes thought – the problem with polls in the US [and Canada/UK] is they’re really politically driven and policy focused – I don’t know who those pollsters are phoneing, but they’re not listening to most folks I talk to

    also an aside here for a number of folks – it’s Flxible, the ultimate “alternative” retirement home :)

  44. 444
    Bob Kutz says:

    Your analysis of the Amazon Gate issue is what is completely without merit.

    You are ignoring the fact that the reference to non-peer reviewed material was necessitated because the peer-reviewed literature had to do with the after effects of logging, and el-nino, both unrelated to climate change.

    Further, from that literature, it becomes apparent that the discussion relates to the vulnerability of the Amazon Rain Forrest (ARF) that has been damaged by logging; which is that about 40% of the biomass of logged acres are very vulnerable to drought. So no acres are in jeopardy, only about 40% of the biomass on the logged acres. Fair enough. But that’s only about 10% of the AFR in total, so 40% of 10% is only 4%, and it isn’t suseptible to drought because of climate change!

    Further, most of Nepstad’s refutation indicates the Nature article failed to reference several unrelated articles, which, if referenced, might give credence to the notion that the reference was acceptable. However; they didn’t reference that paper at all, they referenced a WWF report instead.

    The reason; the WWF supported the claim, the Nature paper clearly did not, and the fact that the Nature paper COULD have referenced several unrelated papers does not change that fact.

    So your notion that Nepstad successfully defended the reference to non-peer reviewed literature by asserting that the non-peer reviewed literature referenced a peer reviewed paper that SHOULD have referenced other peer reviewed literature that WOULD have supported the claim is charitably dubious at best.


    Bob Kutz

    [Response: Completely wrong. As Nepstad makes clear, the issue was not with the citations in their various articles in Nature, but rather those in the WWF report, which only cited Nepstad et al 1999. The actual basis for the (correct) IPCC statement on drought sensitivity is instead based on papers in 1994 and 2004.–Jim]

  45. 445
    Completely Fed Up says:

    Axle:”PS It would be appreciated if CFU (for instance, @383) didn’t respond to this post. His extraordinary talents would be far better employed outside of this blog.”

    He really is sooo braaave Sir Robin!

    “And I certainly never said “ignore the evidence”! ”

    I’ve dug back in the mists of time to recreate the past:

    “The evidence, whatever it says, is meaningless, ”

    Of course, you may consider this evidence meaningless. However this would confirm the hypothesis you wish to deny.

  46. 446
    Didactylos says:

    CFU said:

    Now, why did you not know what page it was on?

    Did you while reading it not notice that it came after 10.10, thereby indicating what need there is for a page reference?

    Did you also forget what the error was so couldn’t say what the error was?

    How do you think you’d get on if you walked into the police station with someone, pointed to them and said “A crime has been committed. Arrest him!”?

    You’d be thrown out as wasting police time.

    The only reason I can see for keeping that information off the post you made was that at the time you didn’t know it.

    Dude, you’re showing the dittos as being mendacious and parroting sight unseen reports of others without evidence of scepticism.

    Are you for real? You made a mistake. Apologise, and move on. Trying to shift blame makes you look like an idiot.

    You don’t get a free pass on RC just because you enjoy baiting the deniers.

  47. 447
    Doug Bostrom says:

    robert says: 17 February 2010 at 10:58 AM

    Seems to me that glacier retreat as an indication of anything beyond a regional effect is going to depend on global statistics as they pertain to glacier retreat. Using earlier glacier retreats as a means to form any conclusions about global effects will require showing statistics of earlier retreats that are relevant to today’s observations.

  48. 448
    ferocious says:

    re 191 Completely Fed Up says: #
    “What that really means is that you are likely to be wrong if you accept the advice.

    No, that would be the result of accepting “unlikely” advice.

    If you *reject* likely advice, then you’re likely wrong. Not if you accept it.

    Please also remember that “wrong” also includes “ohshit, we’re gonna die”, which is hardly a reason for inaction.”

    Puhlease Fed Up go back and learn a bit about how to use statistics. None of the physical sciences accept confidence intervals below 90% as showing much validity. The only place you see them accepted is in social sciences and psychology because human subjects are so notoriously fickle and the sample sizes so small you ‘d never get any data at all unless you use wider limits, recognizing that there is a very real probability it’s wrong. In many cases even 95%CI should be termed no better than likely. Do you realize that the airliner you fly on is based on somewhere in the 99.999% CI? That means it is very likely you will make it to the next airport. Only the adventurous and desperate fly with a 5% chance crashing on their next trip.

    The main point of this is that the AR4 is wrong to use terms such as “Very likely” “likely” or any other kind of qualifier when forecasting. The terms are useless in making any kind of a decision. Statistics are about generalities about a large sample of whatever. They can’t say a thing of validity about one thing in particular. The insurance company might say you have one chance in 40,000 of dying in a car crash the next time you drive. Will you crash or survive the next trip? There’s absolutely no way to say.

    And get a grip on the real consequences. Even the AR4, although it is rife with catastrophic scenarios, really never says anything more than we might seriously expect a rise in world temperature of 1.6 deg. C. along with increased CO2 in the atmosphere. Given the wide range of climates people already live in, moving from Houston to Kansas is hardly the kind of change that is going to kill off the human population.

    [Response: You have completely misread the IPCC use of these terms. They are best understood as Bayesian expressions of expert judgement. It is very likely indeed that the planet has warmed (i.e. there are many different lines of evidence that support this and the chance that they are all wrong is very slim). Why is this problematic? It is very likely that that most of the recent warming is anthropogenic (i.e. given what we know about the history of greenhouse gases, and natural forcings and aerosols we get the best explanation by far if we include the anthropogenic effects, and we can’t make it work at all if we don’t). Why is this problematic? And your assessment that IPCC only projects a maximum of 1.6 deg C temperature rise is way off the mark (and pretty unlikely I’d say) – gavin]

  49. 449
    Ray Ladbury says:

    AxelD, OK, let’s reset. First, your recommendation to overhaul the IPCC is pretty much impractical. For one thing, pretty much anybody who demonstrably understands anything about climate (aka those who publish) is already part of the process.

    Your argument of independently assessing the data is also problematic. Who do you get to assess it? National Academy of Sciences? Done. Royal Society? Done. Professional societies? Done. AAAS? Done. Sigma Xi? Done. Nothing that has happened in the past few months casts any doubt on the basic science of climate change. Why would you expect a different outcome this time? And more important, why would you expect those who doubt the veracity of the scientists to accept the results of a new review, regardless of who conducted it.

    I think that there is a tremendous misunderstanding of how the IPCC works. It doesn’t do research. It doesn’t direct research or fund research. All it does is summarize. So, let’s ask the people whose papers are being summarized how good a job the IPCC is doing. The latest survey by Bray and von Storch (hardly alarmists) did just that–and the overwhelming majority are satisfied or very satisfied.

    Now we can go through all these analyses and exercises again and again. What makes you think the outcome will be different? What will stop the character-asassination machine the hard-core denialists are running from taking aim at any scientists or analyses?

    Insanity is doing the same thing over and over and expecting a different outcome. Climate science has been submitting to continual external reviews and setting standards for openness for 20 years. Golly, look how well that has worked. The more universal the agreement on the science and the more open the process, the more the denialists yell “Fraud.”

    Some people are not educable. If people choose to listen to them, then we will miss this opportunity to address the threat. There will be other opportunities. The costs will be higher. The remediation more draconian and the chances of screwing up due to public hysteria greater, but they will come with increasing frequency as climate change intensifies. If we miss those opportunities, well then I guess humanity flunked its intelligence test.

  50. 450
    Ray Ladbury says:

    Let me get this straight: You have to go clear back to medieval times to find an instance of science not self-correcting? Ever hear of Francis Bacon–you know the guy who developed the scientific method? I personally think that it would be difficult to be a scientist before the invention of the scientific method. Ferchrissake, the word science dates from the early 1800s!

    Now as to the not-so-good Rev. Malthus, his basic thesis is not wrong. He merely failed to anticipate the safety valve offered by
    1)large tracts of land in the Americas that could be stolen from the natives
    2)that we could find a way to turn petroleum into food (green revolution).

    Rev. Malthus will be proven correct within the next 1500 years. That is the time at which given current growth rates, the mass of human beings on planet Earth will equal the mass of planet Earth. I see a pretty severe issue there, particularly since there are no other habitable planets known. Now you may contend that population will peak at 9-10 billion in 2050. Well, Malthus would still be correct, because he premised his pessimistic assessment on humans not controlling their breeding.

    Sorry, Andreas, it is a mathematical certainty that growth (economic or population) cannot continue without bound.