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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. 201
    Ray Ladbury says:

    I don’t rely on either past or present chairmen of the IPCC. I rely on the data in peer-reviewed scientific research, thank you. The fact that the IPCC underestimates do not reflect the rapidity of degradation in the cryosphere is well known and has been for a long time. See here:

    and here

    and here

    Gee, Axel, all these facts right here on this very site and you never knew it. I’ll take facts over opinions of past or present IPCC chairmen, but then we already know your elastic attitude towards facts.

  2. 202
    PhilinAZ says:

    Even Phil Jones is now saying there is no significant warming in the last 15 years. It’s a matter of time before this whole thing falls apart–if it hasn’t already. I think the whistle-blower that started Climate-gate should be up for a Nobel Peace prize for saving the whole world BILLIONS of dollars!

    [Response: You wish, and you would. Think your billions will buy you a new planet do ya?–Jim]

  3. 203
    Martin Vermeer says:

    Eric Smith #166, eh, 0.161 degrees is the decadal rate… please come back for lesson 2 ;-)

  4. 204
    Tim Jones says:

    Re:110 Andreas Bjurström says: 15 February 2010 at 6:41 AM
    “The arrogant scientific attitude of the IPCC, i.e. the recurrent claim that science is objective and the assessment free of errors, are the fundamental cause of the present debate. If the IPCC had been more humble, the sceptics spinn based on a sigle error would not be possible.”

    Blowing smoke. Aspersions on the IPCC from a gang of tinfoil hats were coming down long before the trigger Andreas Bjurström mentions.


    “Inhofe Calls UN IPCC Summary For Policymakers ‘Corruption of Science'”
    By EPW Blog
    Saturday, February 3, 2007

    “Washington, DC – Sen. James Inhofe, (R-Okla.), Ranking Member of the Environment & Public Works Committee, today commented on the UN Intergovernmental Panel on Climate Change’s (IPCC) Fourth Assessment Summary for Policymakers.

    “This is a political document, not a scientific report, and it is a shining example of the corruption of science for political gain. The media has failed to report that the IPCC Summary for Policymakers was not approved by scientists but by UN political delegates and bureaucrats,” Senator Inhofe said. The IPCC is only releasing the Summary for Policymakers today, not the actual scientific report which is not due out until May 2007.

    “This is nothing new. On November 15th, 2005, I addressed my colleagues in the United States Senate to express the importance of returning integrity to the processes that govern the work of the IPCC. I outlined several concrete proposals to reform the IPCC process during this Senate Floor address and in a subsequent follow-up letter to the IPCC chairman,” Senator Inhofe said.

    “On December 7, 2005, I followed up my speech with a letter to the IPCC Chairman noting that the ‘science had been manipulated in order to reach a predetermined conclusion.’ Sadly, the IPCC has refused to make any of the reforms necessary to ensure scientific integrity,” Senator Inhofe added.”

  5. 205
    Didactylos says:

    Eric Smith said something inconsequential and error-filled.

    And I say: if global warming was linear, it would hardly be the problem that it is.

    Eric: you can’t read. The trend for 1975-2009 is 0.161 degrees per decade. That’s 1.61 degrees per century.

    Epic reading comprehension fail.

  6. 206
    mike roddy says:

    Thanks, Gavin. This is a great summary that can be easily referenced. More importantly, it should be distributed as an urgent press release to all members of the media.

  7. 207
    Ray Ladbury says:

    Ferocious says “Before you even look at the data you decide on how important the conclusion is going to be. The more important, the more strict the statistics. 95% confidence interval has been traditionally used because it is wide enough to be attained in many instances, but robust enough that unfounded conclusions aren’t very likely be made.”

    Now, hold on just a wee minute here! Are you seriously contending that the standards for scientific truth be contingent upon the desirability of the conclusions? Because if you are saying anything even remotely like that, I believe you are proposing a rather significant change to the scientific method.

    CO2 sensitivity below 2 degrees per doubling is precluded at the 95% confidence level. The fact that every year this decade except 2008 has been among the 10 warmest and that 17 of the top 20 hotest years on record have been in the past 20 years (the others were all in the ’80s) precludes random chance at better than 95% confidence even with red or pink noise! The fact that the stratosphere has been cooling as the troposphere warms is absolutely diagnostic of a greenhouse mechanism. Want me to go on?

    I’m more than willing to talk evidence, ferrocious. It’s much more interesting than typos and email gossip.

  8. 208
    Didactylos says:

    noel got upset about funding.

    Noel, where do you stand on tobacco? Do you think it is fine for tobacco companies to spend millions on lying to the public?

    Do you think the doctors and scientists who exposed the lies should be treated the same way as the tobacco industry lobbyists merely because they have a vested interest in making people well?

    Yes, it’s absurd. Of course it’s absurd. But now the whole song and dance is repeating with fossil fuel interests in the tobacco seat. Many of the people involved are the very same people from before!

  9. 209
    Ray Ladbury says:

    Jack Kelly says: “MetaGate: The scandal whereby journalists lack the imagination to come up with a better suffix than “-gate”.”

    Oh, I am soooo stealing that!

  10. 210
    Martin says:

    Eric Smith (166): “According to Professor Phil Jones, the period 1975-2009 (35 years) had a stastically significant temperature rise of 0.161 degrees.

    That represents 0.46 degree per century, which will have no substantial negative effect on the climate of the planet.”

    It would appear that in a rush to make your case you didn’t read the caption on the table. It says that is the trend per decade, not the rise over the period in question. Thus, that’s 1.61 degrees c in a century. Which is, of course, not particularly relevant. The climate system is rife with feedbacks, with positive feedbacks dominating, so a linear extrapolation likely understates the case.


  11. 211
    Septic Matthew says:

    135, Ray Ladbury: CO2 has been known to be a greenhouse gas since the 1850s, and anthropogenic climate change due to CO2 was first predicted in 1896! Good lord, where do you come up with this?!
    There are a dozen or so independent lines of evidence that all favor a CO2 sensitivity around 3 degrees per doubling–and preclude a sensitivity less than 2 degrees per doubling.

    I did not dispute that. I said that the theory is not complete and not precise. The VAR methods show that the association of temp change with CO2 change, in the actual record, is not very strong. The authors whom Gavin disparaged did not claim that there was a “neat” relationship of temperature change to CO2 change, only that it was estimable within a class of functions. Probably, as this line of modeling is extended, better functions will be found to relate the measured variables through time.

    In complex systems, it is not that unusual to find that a particular well-defined causal mechanism has a small effect in the whole system. The VAR methods merely substantiate the possibility that other factors, not well known or known at all, might overwhelm the CO2 effect.

  12. 212
    Ray Ladbury says:

    noel@168 Uh, Noel, Al Gore is a politician, and not a very good one at that. Why you wanna go to him for climate info. Likewise, why do you want to go to a whole bunch of nonscientists for climate info. If it were me, I’d look to the climate scientists–you know, the ones who actually publish.

  13. 213
    Ray Ladbury says:

    ferrocious cites “Energy and Environment, ” and that’s all you need to know. Dude, Weekly World News has more credibility in scientific matters!

  14. 214
    Bob says:

    Ruth, #160:

    So is Professor Jones saying that there is simply not enough Southern Hemisphere proxy data to support a global temperature reconstruction dating back over 1000 years?

    No, he’s saying that there is not enough Southern Hemisphere proxy data to support the contention that the entire globe was anomalously warm for a 300 year period from 950 AD to 1250 AD.

  15. 215
    mike roddy says:

    Ike Solem, #182, excellent, again.

    IPCC is also quite remiss in their deforestation sections. While conceding the emissions caused by logging, they give industrial logging a pass, suggesting that better ways to clearcut may be the answer.

    I have been asked to deliver a paper on CO2 emissions for various construction materials to an international conference this summer, based on some of my prior work. If anyone can suggest carbon scientists with particular expertise in calculating emissions from forestry, steel, and concrete production, I would like to hear from them at I have found the US EIA tables to be flawed and incomplete at times, and need better data.

  16. 216
    Tim McDermott says:

    Harry Hodge:I think you are missing what statistically significant means, and how that significance relates to the length of time in question. Professor Jones was saying that there is more than one change in 20 that the 1995 to 2009 temperature rise was due to chance, vice random fluctuations. Statistics are (mathematically) quite beautiful. But completely non-intuitive. Consider the temperature on Feb 15th. In Northern Virginia, the average high is 45F. Today’s high will be 37F. Nobody would be surprised if Feb 15, 2011 the temp were 55F. There is a lot of jumping around from year to year. Indeed, the record hi/low is 68F/7F. So for a trend to be statistically significant in 14 years means it has to be a very strong trend. But the temperature trends we are looking at are on the order of hundredths of a degree per year.The longer the period, the easier it is to find the trend.The correct answer to the BBC’s question was not the one Dr Jones gave; the proper answer was that 14 years is too short a time period for meaningful trend statistics.

  17. 217

    “One of them wrote that the experience with Leake had made him “reluctant to speak to any journalist about any subject at all.’ ”

    I think this was rather the whole point, wasn’t it?

  18. 218
    Andy says:

    From Eric Smith: “According to Professor Phil Jones, the period 1975-2009 (35 years) had a stastically significant temperature rise of 0.161 degrees.

    That represents 0.46 degree per century, which will have no substantial negative effect on the climate of the planet.”

    I’d think after reading this that one would have a lot of questions like:

    Is the trend in higher global temps stable, accelerating, decelerating or what? (current trend is about 0.2C per decade or 2C per century)

    What about periods before or after the one reported?

    Are there other data sets and do they show the same trends?

    What is the cause of the underlying trend and what does this mean for future temperatures?

    At what level does an increase in global temps start to affect the world?

    Is the temperature increasing at the same rate everywhere on the globe?

    You can find all the answers to the above in this blog’s archived posts and supporting information.

    The years 1975 to 2009 are only a small part of a long, now upward accelerating trend of global temperatures. And those areas that occupy the most space on Earth; the oceans and tropics, are increasing only slowly in temperature while others, like the northern hemisphere continents where most people live, are increasing rapidly in temperature and are projected to do so more rapidly in the future.

    On top of this, there is a lot less difference in yearly average temperature than one would casually expect from one place to another though those places obviously experience radically different climates. For example: the average annual temperature of Peoria, Illinois is about 51F and that of Austin, Texas is 68F. They receive the same annual precipitation (about 36 inches).

    Yet, no one who was familiar with these cities would ever confuse one for the other. The plant life, wildlife, water availability, crops, building construction methods and everything else dependent upon climate are radically different between these two cities though they receive the same amount of precipitation, are located at roughly the same longitude, and are subject to the same climate controllers (i.e. Rocky Mountain rain shadow, central continental climate, etc.).

    GISS has many articles written for non-climate scientists that explain and illustrate the coming Austinification of Peoria, Chicago, and other midwestern US cities. I’ve lived in both areas and Austin, frankly, sucks in the summer.

    Also, reasons for DC’s heavy snow. 200% above normal precipitable water levels in the atmosphere resulting from a warm, El Nino Pacific was a critical piece of the puzzle at these Univ. of Wisconsin folks discuss.

  19. 219
    flxible says:

    Theo Hopkins@113 – groups 1 & 4 will revert come summer, the real core point is joe six pack can’t tell the difference between snow in a British winter and ice in an Arctic summer or between weather and climate.

  20. 220
    flxible says:

    Trysail@128 “the record snow we are seeing this winter is due to cold, not warm temperatures”

    Exactly, as in the AO causing a shift of Arctic [cold] influences on top of ElNino bringing you increased precip – OTOH, the record warmth and rain seen this winter on the other side of our continent [think “green” Olympics] has similar influences involved in a different place. You might consider this discussion has to do with long range global climate, not seasonal local weather. Your local weather reporters are handing out sound bites, not science.

  21. 221
    flxible says:

    Ian Rae@142 “The issue that you really need to address is why these errors that get missed by the review process tend to lean in one direction — that of alarmism. Chance or bias?”
    The issue you need to address, as mentioned by others above, is why you miss any errors that lean in the other direction? [see Bart Verheggens comment@159] Chance or bias? But of course your criticism has to do with the review process, not the science, so maybe you really need to address those “reviewers” of the review process you get your bias from?

  22. 222
    flxible says:

    Didactylos@158 “Shame on the BBC interviewer for failing to filter questions that are obviously designed to solicit a particular answer.”
    Actually consideration of the questions there [and the constrained written format] make it obvious the BBC did “filter” the questions, probably through a legal department [and maybe not the BBC’s], and Jones answers appeared to have been subject to a similar filter, which is why he didn’t state things quite clearly enough to prevent the misinterpretations seen in comments here.

  23. 223
    Stephen Mc says:

    Per post # 75, Anand:

    I watched, on the “Democracy Now!” cable channel, a circa 2001 Global Warming documentary, that predicted 50 Million AGW refugees by the year 2010. !

    There are enough of these 10 to 15 year old ‘predictions’ out there to really see the predictive power of Climate Science.

    [Response: If you can’t tell the difference between actual climate science and something in a TV “documentary”, you’ve got some fairly serious problems.–Jim]

  24. 224
    Ron Taylor says:

    Thanks, Ike (182). The new TV ads being run by the coal industry really illustrate the new deception campaign. It is clear that the strategy has changed.

  25. 225
    Phil. Felton says:

    Phil Jones – Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.

    As pointed out above this is a correct answer but unfortunately is rather opaque to ‘Joe Public’. A better way to put it would be ‘the calculated warming rate is 0.12ºC/decade, the chances of this being due to the scatter in the data is less than 1 in 10. As the period that the measurements are taken increases it becomes more certain that the warming trend is accurate’.

  26. 226
    Deep Climate says:

    More nonsense from Leake, relying on Christy and McKitrick to demonstrate the land temperature record is hopelessly biased:

    And a quick rebuttal at Deltoid

  27. 227
    Jim Galasyn says:

    Why you need 30 years of annual data to infer a surface temperature trend: Results on deciding trends.

  28. 228
  29. 229

    ADR: How long will this “blip” of no warming since 1998 last?

    BPL: There is no such blip. Look for yourself:

  30. 230

    peterr: The theory that this climate change is caused by human factors is entirely possible but not “settled” or even much based on “science”.

    BPL: As if you knew any of the relevant science yourself.

  31. 231
    Tim Jones says:

    Re:168 noel says: 15 February 2010

    n: “But wait, dismissing skeptics because they might have ties to oil companies is ok?

    Probably. These are entrenched industries disseminating mendacious propaganda to deceive people into believing there’s no problem with ghg emissions when there is. These “skeptics” are likely parroting lies for personal gain.

    n: “What’s the difference between eg Al Gore investing money in green industries and promoting AGW, and others investing in oil companies and promoting anti-AGW? Double standard much?”

    Nah. Al Gore has been donating 100% of his profits to his non-profit environmental group The Alliance for Climate Protection.

    It’s delusory and conspiratorial to believe Al Gore is promoting AGW to enhance his investments. He is obviously putting his money where his mouth is, though. Besides, investing money in green industry accrues many benefits besides the attenuation of climate change, though the success of such enterprise would be helpful. There is little risk or detrimental consequence of having alternative energy applications be part of the economy.

    Investing in fossil industry by promoting positive aspects is one thing. But to tear down the virtual consensus of science
    that GHG emissions are harmful to make a buck is quite another. There is risk here. As far as I’m concerned the propaganda is dangerously mistaken.

    One kind of investment promotes the general welfare of society. The second promotes personal greed and the destruction of society. Think there’s a difference?

    Okay, let’s admit that for the time being fossil fuels are an integral part of civilization. The program here should be
    to recognize the scientific facts alluding to how burning several million years worth of fossil sunshine in less than two hundred has consequences. Climate change. Peak oil. Society should act with an eye to the future in responsible ways to enable the least destabilizing way of integrating new technology with old cultural norms to work its way out of the unbridled explosion of opportunity.

    There’s nothing wrong with leaving some coal and oil in the ground for future generations to make use of. Why is it incumbent on the current generation to use the world’s resources up as fast as it can? Thus some fossil fuel industry investment should be converted into actually sustaining the industry in ways that individual companies survive while helping society to survive the long run.

    The problem we’re experiencing here is hysteria derived from the fear of losing an unsustainable lifestyle. If we would learn to keep the good parts and thrown out the extravagant and wasteful we could probably avoid being so tense about all this and get on with taking care of the children – which is what evolution is all about, isn’t it?

    So let’s evolve.

  32. 232

    peterr: But “Climate Science” is an invented discipline and has a history shorter than my pubic hair.

    BPL: And I imagine you shave it. Let’s review the history of climate science.

    ~300 BC. Aristotle divides the world into “torrid,” “temperate,” and “frigid” zones.

    ~1660 AD. Torricelli invents the barometer and demonstrates that air pressure decreases with altitude.

    ~1745. Hadley charts the world’s major air currents for the first time, including the huge cycles now called “Hadley cells.”

    1824. Fourier speculates that Earth’s atmosphere is keeping the surface warmer than sunlight alone could do it.

    ~1850. Louis Agassiz shows that Earth went through one or more “ice ages.”

    1859. Tyndall demonstrates with lab work that the major greenhouse gases in Earth’s atmosphere are water vapor and carbon dioxide.

    1896. Svante August Arrhenius (chemistry Nobel Prize 1908) proposes the theory of anthropogenic global warming (AGW), including such details as sensitivity to doubled CO2, polar amplification, and greater warming at night and during winter.

    1901. Knut Angstrom and J. Koch show that one atmosphere’s worth of CO2 absorbs about as much infrared light as 4/3 atmosphere’s worth, inferring that adding CO2 therefore doesn’t matter.

    1919. Dines publishes the first energy budget of Earth’s climate system.

    1931. Hulbert outlines the theory for a radiative-convective model (RCM) of Earth’s atmosphere.

    1938. Callendar suggests that CO2 has probably risen over the past century and that the world has warmed in consequence.

    1940-1945. High-altitude observations show that absorption differs at different pressures and altitudes, and that warming in even the topmost layer can affect the ground.

    1948. Haur publishes albedo estimates for high, middle, and low-altitude clouds.

    1955. Smagorinsky et al. write the first general circulation model (GCM) of Earth’s atmosphere.

    Suess suggests that the radioisotope signature of new CO2 shows that it is coming from burning fossil fuels.

    1956. Plass gives a quantitative estimate of what is now called Charney sensitivity, disproving Angstrom’s “saturation argument” once and for all and effectively making AGW part of the consensus.

    1957. Revelle and Suess confirm Suess’s earlier work, showing that the new CO2 is indeed coming from fossil fuels.

    1958. Revelle, Keeling and others establish regular flash sampling of remote-location CO2 at Mauna Loa observatory, Hawaii. Their findings are soon confirmed at other remote sites, including Antarctica and Siberia.

    1960. Keeling et al. show that CO2 is steadily rising.

    1964. Manabe and Strickler publish the first working RCM.

    1967. Manabe and Wetherall improve the model by substituting a fixed relative humidity scheme for the earlier fixed absolute humidity distribution.

    1971. Suomi et al. obtain the first accurate estimate of Earth’s bolometric Russell-Bond spherical albedo from satellite observations.

    1975. Manabe and Wetherall link their radiation code into a general circulation model.

    1988. Hansen warns congress of global warming.

    1989-present. Exxon-Mobile and other fossil fuel interests pour tens of millions of dollars into right-wing think tanks and grants to assorted crackpots to try to disprove AGW, or at least pretend to have disproved it.

    2002. The Larsen B ice shelf collapses for the first time in 10,000 years.

    2004. Dai et al. provide world maps of the Palmer Drought Severity Index for the period 1870-2002. They show that in 1970, 12% of Earth’s land surface was “severely dry” (PDSI < -3.0). By 2002 the figure was 30%.

    2008. Massive droughts temporarily cut into Australian agricultural production by a third.

    So is it a new field? Or is it just your acquaintance with it that's new? AGW theory ALONE is 114 years old, and climate science goes back well before that.

  33. 233

    septic: if a credible analysis shows that the fluctuations in solar activity (to pick one example) are more strongly related to temperature changes than the CO2 changes are related to temp changes is evidence that a large component of the causal mechanism is still unknown or misspecified.

    BPL: Fraction of variance of NASA GISS global annual temperature anomalies, 1880-2008, accounted for by variations in solar constant: 2.5%.

    Accounted for by changes in carbon dioxide: 76%.

    Do the math.

  34. 234
    Didactylos says:

    PhilinAZ: you’re one of those deluded people who can’t tell the difference between a criminal hacker and a whistleblower? Not only that, you can’t understand a simple statement about significance of a trend.

    Either you are really, really unqualified for this discussion, or you are repeating lies you have been fed without actually thinking about it or researching the true facts.

    Jones’ comments have been expanded on many times in this comment thread. Please read, please learn. If you don’t understand anything, then ask, instead of making silly accusations.

  35. 235
    Ray Ladbury says:

    Septic Matthew,
    Given how noisy the climate system is, this looks like a pretty strong correlation to me:

    In any case, the argument is not from correlation, but from the fact that we know CO2 is a greenhouse gas. This was the argument Arrhenius made long before the correlation was observed.

    And what other factor do you contend explains more of the anomaly?

  36. 236
    Dennis says:

    Andreas Bjurström,

    You make a number of valid points — and good luck with your research. Yes, the IPCC process is at times messy, its public image at times is ugly, and many scientists make poor public figures. However, I live in the United States, where we have a much bigger problem.

    The IPCC is right to put social science on the back burner in a political atmosphere where the facts of the physical science basis are under such nonsensical attack. We have senior policy makers who deny the basic science. I see elected leaders on the floor of Congress deliverying lies about scientific facts and going unchallenged. Until a year ago our president was one of them. To turn this around in the country that is both most responsible for global warming and in the greatest denial about it is paramount.

    In short, I am not proud of what my country has done on climate issues, and every day we are still going through the basic 2+2=4 arguments in the physical sciences to get people to wake up to the reality. I struggle with this every day, and if I may offer you a suggestion, I think the social science community would better serve the truth if it performed sociological research on why so many people are willing to believe 2+2=5 instead. The scientists may be a part of the problem, but I suspect it’s a lot more than that.

  37. 237
    Jerry Steffens says:

    Re: The Phil Jones statement

    To say that there hasn’t been statistically significant warming over a short period is like a parent finding that his or her child has not exhibited any statistically significant growth this month. (Time to start prescribing the growth hormones!) Or, like travelers headed west from Kansas City not seeing any statistically significant rise in elevation over the last 10 miles. (Better turn around; we must be headed in the wrong direction!)

    [Response: :)]

  38. 238
    Didactylos says:

    peterr: the discovery of DNA came far more recently than the discovery of the greenhouse effect and the possibility of global warming. We routinely use DNA to justify incarcerating or even executing huge numbers of people every year.

    So, why aren’t you up in arms about this “newfangled DNA”?

  39. 239
    Patrik says:

    Fascinating reading on this blog and it’s offsprings in other places.
    I didn’t know that there where so many ways of saying “the text doesn’t say what you think it says”.
    Is that really a good way of answering questions/criticism?

  40. 240
    Doug Bostrom says:

    When is Dr. Pielke Jr. going to produce some evidence to support his claim of a “classic and unambiguous case of financial conflict of interest” on the part of Dr. Pachauri??

    Dr. Pielke Jr. infers this has happened, expects the world to share his concern, but Dr. Pielke Jr. has not produced any actual data to support his inference.

    So far, it appears that Dr. Pielke Jr. is prepared to appear here making sanctimonious comments about the behaviors of other researchers, about unsupported claims, when he himself is making a claim that is so far unsupported by any data or hard evidence.

    I’ve read Dr. Pielke’s further comments about this matter here, they are unpersuasive because they don’t include any facts directly pertinent to Dr. Pachauri and the negotiation process to which Dr. Pielke Jr. refers.

    But perhaps the ongoing silence is because Dr. Pielke is working on a chronology that exactly illustrates without any ambiguity how such a serious charge is supported by facts.

  41. 241
    Andreas Bjurström says:

    @203 Tim Jones, there are certainly some tinfoil hats around. So what?

    However, the IPCC has recurrently stated being free of errors and objectivity for the last twenty years. This has been the IPCC strategy to making climate change a policy issue from the start. bert Bolin, the first chairman of the IPCC, started with this in the early 1970´s in Sweden (I did an interview with him a few years ago on this).

    Moreover, to claim that the IPCC assessment is mere a scientific report with no considerations of policy, signify that the IPCC is 1) tinfoil hats themselves 2) or rather dishonest on what they are doing. I believe that a mix of 1 (the naivety of the natural sciences when it comes to the theory and sociology of science) and 2 is the case.

    To claim scientific purity (100 % truth, 100 % disinterestedness, objectivity, etc, etc) is madness for a social scientist, especially for post normal issues like climate change where science is so infected by politics. For a social scientists (interested in the sociology of science) this is the equivalent to deny the most basic facts on the physical aspects of climate change. I find most climate scientists to be extremely ignorant to most aspects of my area of expertise.

  42. 242

    […] on the IPCC errors and their significance By Bart RealClimate has a good post on the recent string of (alleged) errors in the IPCC report. It explains the IPCC proces, […]

  43. 243
    John Peter says:

    Barton Paul Levenson (109)

    Thanks for the reference to the Clement/Burgman/Norris paper. Well organized, it seemed to make sense to me.

    I fail to see how 16 out of 18 models got the feedback sign wrong and for low-level clouds yet! Only one got correct – agreement with data – results. For a 20+ year old key technical problem, in a “settled” science, for the predictors of future climate change, 4% success rate seems pretty lousy to me.

    It’s easy for this scientist to jump to a conclusion that IPCC is not doing a very good scientific job for all the reams of reports. Can someone straighten me out?


  44. 244
    Didactylos says:

    flxible: that’s your opinion. Personally, I see no evidence of legal tampering, and, as always, Jones’ answers are a paragon of technical perfection.

    My own opinion is that the questions ramp up in a manner that cannot be by chance. They are clearly leading, and nearly all the questions are loaded. I am not happy with the way the BBC handled this.

    Journalistic integrity died a long time ago.

  45. 245

    septic: The VAR methods show that the association of temp change with CO2 change, in the actual record, is not very strong.

    BPL: Look again:

    I find r = 0.874 between ln CO2 and dT for 1880-2008. Did I make a mistake somewhere? If so, please point it out.

  46. 246
    Jeffrey Davis says:

    Has anyone asked the question about why the BBC interviewer specified “15 years”? What’s so special about 15 years?

  47. 247
    Dan Ives says:

    To all RealClimate contributors,

    Thank you once again for a detailed and easy-to-follow post. Your efforts to clear the muddy waters and educate the public are honorable endeavors. I am sorry that you must constantly defend yourselves and your research from baseless attacks and ignorant interpretations. You have inspired me to educate my friends and family about the seriousness of climate change and also to write letters to several government officials on the subject. Regardless of where we are 30-40 years from now, I hope you realize that our children will look back on your actions and see how hard you fought on behalf of their future.


    -Dan Ives

  48. 248
    flxible says:

    Ron Taylor [and Ike] In Canada Shell Oil has TV ads [in conjunction with print media- “see Sunday’s paper”] trumpeting their oil sands carbon sequestration “initiave”, funded by the Alberta govt with nearly 1 billion taxpayer dollars – of course they don’t let on the use for the CO2 captured will be to enhance recovery from their declining wells. Of course to the contrarians, increasing corporate profits with taxation must be much better than taxing their products to support real alternatives.

  49. 249
    Tim Jones says:

    Re:212 Ray Ladbury says: 15 February 2010 at 1:26 PM
    “Al Gore is a politician, and not a very good one at that.”

    Except that a majority of the people of the US elected him president and he won a Nobel Peace Prize
    for work to save the planet from climate change.

    But yeah. What has he done for us lately?

  50. 250
    Tim Jones says:

    “Oceans’ acidity rate is soaring, claims study”
    By Steve Connor, Science Editor
    Monday, 15 February 2010

    “The rate at which the oceans are becoming more acidic is greater today than at any time in tens of millions of years, according to a new study.

    “Rapidly rising concentrations of carbon dioxide in the atmosphere mean that the rate of ocean acidification is the fastest since the age of the dinosaurs, which became extinct 65m years ago, scientists believe.

    “The oceans are likely to become so acidic in coming centuries that they will become uninhabitable for vast swathes of life, especially the little-studied organisms on the deep-sea floor which are a vital link in the marine food chain.”

    “When the oceans became acidified in a similar way about 55m years ago, it resulted in a mass extinction of deep-sea marine organisms, especially those living in the sediments of the sea floor, which can be studied geologically through changes to rock formations, said Dr Andy Ridgwell of the University of Bristol.”