Sceptical of the sceptics

I have a review of Christopher Booker’s book The Real Global Warming Disaster in the Observer today. Here it is below in its original form. I’d be surprised if Booker, or other sceptics, don’t respond in some way, so here too is some of the further comment at which I hinted in the review. And not that it is likely in any way to prevent Booker from dismissing me as a minion of the great conspiracy that is the ‘global warming consensus’, but I’ll just mention too that I have also taken some flak in the past from James Hansen, Booker’s prime villain as the man who (he says, absurdly) almost single-handedly got the global-warming juggernaut on the road. I didn’t endorse Hansen’s call for a more forcefully worded message from the scientific community to supplement what he considered to be the reticence of the IPCC. My view was that, while I understand and sympathize with Hansen’s motivation, the IPCC’s caution has been to its great credit, and has helped maintain its credibility. Needless to say, to Booker the IPCC is simply a cabal of alarmists.

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Considerable effort has gone into Christopher Booker's definitive manual for sceptics. Shame he's talking bunk, says Philip Ball.

Christopher Booker, Sunday Telegraph columnist and bête noir of climate campaigners, has here produced the definitive climate sceptics’ manual. That’s to say, he has rounded up just about every criticism ever made of the majority scientific view that global warming, most probably caused by human activity, is underway, and presented them unchallenged. If you share his convictions, you’ll love it (although I’m not sure you’ll actually wade through the dense arguments), and will dismiss the rest of this review as part of the cover-up.

Me, I was moved to a queer kind of admiration for the skill and energy with which Booker has assembled his polemic. Unlike other climate-sceptic diatribes like the Channel 4 documentary The Great Global Warming Swindle or the writings of Nigel Lawson, this one cannot be dismissed with off-the-shelf knowledge. And some of it is true. But much, including the central claim, is bunk.

Some of Booker’s stratagems are transparent enough. One is to introduce all climate sceptics with a little eulogy to their credentials, while their opponents receive only a perfunctory, if not disparaging, preamble. This reaches its apotheosis on the back cover with a quote from  ‘the world’s leading atmospheric physicist and ‘climate scientist’’, MIT professor Richard Lindzen. Unusually for sceptics, Lindzen does have significant academic status, but probably only his mother would endorse this description. Besides, it seems odd that someone so intent on raising platforms of authority should also ask us to believe that the credibility of the entire Intergovernmental Panel on Climate Change (IPCC) has been undermined by an Australian computer consultant.

Another of Booker’s techniques is to latch on to genuine flaws in the science or its dissemination with the tenacity of a bulldog. Predictably, he attacks the infamous ‘hockey stick’ graph, a plot of global mean temperatures over the past 1000 years produced by two scientists in 1998 which shows little change for the entire period until suddenly soaring in the twentieth century. It is now mostly accepted that the analysis that produced these data was wrong. The question, still unresolved, is ‘how wrong?’ – have we experienced comparable warming in the historical past, in which case the argument that it is a natural fluctuation seems plausible, or is the current trend truly unusual? But Booker’s implication that the entire edifice of the global-warming consensus rested on the shaky hockey stick is absurd: it was one strand among many. For a balanced critique of this episode, look instead to Richard Muller’s Physics for Future Presidents (Norton).

In the end, however, the devil is in the details. And therein lies the problem, for to persuasively dismantle Booker’s case would require an equally long and citation-encrusted tome. You are going to get nothing more (here at least) than my word for it that, say, the first of Booker’s accusations about faulty science and procedural misdemeanour that I chose at random to investigate further – the resignation of hurricane specialist Chris Landsea from the IPCC in 2004 – proved to have a rather different complexion from the one presented here.

Yet some of the cracks become evident just from paying attention. When Booker commits the cardinal sin, for which climate scientists have often castigated alarmists, of making a swallow into a summer (or here, winter) by using the cold snap of 2008 as a reason to doubt the warming trend, it’s game over. And by claiming that the slight cooling trend since around 2003 undermines the IPCC’s climate models, he fails to understand that different timescales demand different models: the projections for 2100 are hardly meant to predict whether next summer will be a scorcher. Don’t even get me started about the graph on page 328 that shows this cooling; just take a look at http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif and then tell me what you feel about it (what do you mean, where is it? It’s that bit at the end). Besides, Booker admits briefly that a climate model in which medium-term ocean circulation was included was able in 2009 to rationalize the current cooling (which may last until 2015). We are supposed to regard this result as suspiciously convenient, but even Booker can come up with no scientific reasons to discard it. Indeed, he later criticizes the IPCC models for failing to simulate shifts in ocean currents. His aim is simply to sling enough mud, and to hell with consistency.

Suppose you are genuinely undecided on climate change, and determined not to be guided simply by what you’d like to believe. If unpicking the real story demands so much effort and insider knowledge, how can you possibly make up your mind? Here’s an unscientific suggestion. Booker’s position would require that you accept something like the following options: (1) Most of the world’s climate scientists, for reasons unspecified, decided to create a myth about human-induced global warming, and have managed to twist endless measurements and computer models to fit their case, without the rest of the scientific community noticing. George W. Bush and certain oil companies have, however, seen through the deception. (2) Most of the world’s climate scientists are incompetent and have grossly misinterpreted their data and models – yet their faulty conclusions are not, as you might imagine, a random chaos of assertions, but all point in the same direction.

There’s a third option, however: (3) The world’s climate system is hugely complex, hard to predict, and constantly surprising; yet in the long term the world is getting warmer, for reasons we basically understand, and there is good reason to believe that humans are mostly responsible for it.

You decide.

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Oh, there is much, much more to be said. As I say in the review, taking on Booker’s arguments means wading through a morass of technical detail and having to get hold of the scientists involved to get the real story. I have done so in just a few cases. If they are representative, then it seems clear what to expect of the rest. Here we go:

Boy, does Booker have it in for David King, former chief governmental science adviser. Quite aside from the specifics, his position here is utterly inconsistent – for example, he says at one point that it’s terrible we set so much store by someone’s credentials as a ‘qualified scientist’ (and thus dismiss Bjorn Lomborg), but it’s apparently equally terrible that we listen to King, a mere ‘surface chemist’. (Bizarrely, ‘surface chemistry’ never appears without its quotes, as though it’s some kind of made-up discipline.) King, says Booker, has little more specialist authority than ‘a man holding forth in a pub’ – or dare we say, in a newspaper column?

The main accusations against King, however, appear in Booker’s account of King’s trip to Moscow in 2004. This was indeed an extraordinary affair, but in the manner Booker asserts. The meeting, instigated by Putin, was supposed to bring together international experts to debate climate change. But as Booker indicates, some of the key Russians were sceptics, and as a result they derailed the whole affair. King was asked to arrange a programme, which he did, including 12 leading British scientists. However, then Putin brought in his economic adviser and head sceptic Alexander Illarionov, who hijacked the meeting and altered the programme, excluding the UK team and inviting several of the key sceptics, such as Nils-Axel Mörner at Stockholm. King and his team were actually en route to Moscow when they were given the revised programme, which immediately shows you the tactics Illarionov was using.

Naturally, King was furious. But he continued to the meeting when it was agreed that the British scientists would be allowed to speak. However, Illarionov insisted on chairing the entire meeting, and King’s team was persistently harangued throughout. The matter was so bad that King had to contact Tony Blair while in Moscow to explain that an international incident was developing; Jack Straw’s chance presence in Moscow at that time helped to prevent it from deteriorating any more than it did, but King was asked simply to try to make the best of it.

Booker alleges that King and his colleagues walked out when challenged with questions they couldn’t answer. In fact, King had announced already that he’d have to leave for another meeting at a certain point, and that’s what he did. As he did so, Illarionov was literally screaming at him that he was not permitted to go. One has the sense that, in former times in the Soviet Union, comrades who disagreed with Illarionov would have lost their jobs and silently disappeared, in the manner of Lysenkoism.

The extensive quotes that Booker provides from Illarionov’s three-hour subsequent press conference pretty much undermine his case in themselves, since they show him to be a borderline hysteric. Indeed, he claimed that Britain had ‘declared war’ on Russia, a claim that was repeated in a headline in the Moscow Times. What Booker doesn’t say is that Putin subsequently sacked Illarionov, who is now a bitter man. The whole episode, far from showing King to be intolerant and scientifically naïve, instead shows how crazy the climate sceptics can become, and how underhand their tactics are.

Next.

I mention the resignation of Chris Landsea in my review. The villain here is Kevin Trenberth, the hurricane modelling expert at UCAR (the University Corporation for Atmospheric Research in the US). Naturally, we hear nothing from Booker about Trenberth’s side of the story. So here is what Trenberth says of the matter:

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Summary:

Chris Landsea was not a Coordinating Lead Author (CLA) or a Lead author of the report.  He was asked by the CLAs to be a contributing author (there are 66 in Chapter 3) who write a half page or so on a particular topics that are assembled into the report by the Lead Authors.  He could easily refuse to do so, but to publicly resign the way he did was a very political approach that had nothing to do with any scientific dispute. 
Trenberth’s response was to publish the scientific basis for the news conference criticized by Landsea in the June 2005 Science, and Kerry Emanuel of the Massachusetts Institute of Technology independently published direct observational evidence in Nature only two months later. He showed that significant increases in cyclone intensity and duration around the world since 1970 have been strongly related to rising SSTs. Challenges from Landsea and other experts have led to modest revisions  in the specific correlations, Emanuel 2005b, but do not alter the overall conclusion. In September 2005 Peter Webster and his colleagues at the Georgia Institute of Technology published an article in Science that explicitly showed a substantial rise in the number of Category 4 and 5 hurricanes since 1970 and in the percent of total hurricanes that fit that description. They concluded that the rise was to be expected, given the observed increase in SSTs.

Landsea’s letter was written late in 2004, and subsequently, in addition to the many new published papers, the record breaking 2005 hurricane season occurred, including hurricane Katrina and 3 other category 5 hurricanes.

There is no doubt that there is large natural variability in hurricanes, and also disputes about how reliable the record is, points made by Landsea (for example Landsea, Nature 2005 and Chan, Science 2006) ; but other articles have demonstrated that the changes in the hurricane environment have a human component, such as Santer et al., PNAS 2006.  

There is a wide range of scientific opinion on the issue, reflecting the genuine scientific uncertainties and developing nature of the science.  Subsequently, the IPCC has also weighed in and the attribution of changes to a human role are clearly stated in chapters that were not authored by Trenberth.  
Trenberth summarizes his views on hurricanes as follows:

1) There is large natural variability of hurricanes.  We can not say anything about increases in numbers or frequency from the record or how these may change in the future.

2) However, the environment in which the hurricanes are occurring is clearly changing, and those changes are part of global warming. 

3) For the past 10 years the SSTs have been higher from 10-20∞N in the Atlantic, where the hurricanes form and track, than at any other time in the record through the 20th C.

4) During this period 8 out of the 10 years had above normal numbers of hurricanes and the 2 exceptions were El Niño years when the main activity shifts to the Pacific.

       1995-2004  1970-1994    2004
TCs    13.6               8.6            14   
Hurr    7.8                5.0             9

1) Water vapor amounts are rising
2) Precipitation has been becoming more intense in the US as a result.
3) Hurricane Catarina off Brazil in March 2004 was unprecedented

5) Hence there is every reason to think that these changes should increase the intensity of hurricanes and rainfalls associated with hurricanes.

6) We can not say anything much about the 4 hurricanes that hit Florida, except that the rainfalls and flooding were likely enhanced by global warming. 

7) The IPCC in 2001 also states that hurricanes are likely to become more intense with stronger winds and heavier rainfalls.

8) While the influence of climate change on hurricanes may not be detectable because of large natural variability, this does not mean that there is no influence.

Landsea writes “It is beyond me why my colleagues would utilize the media to push an unsupported agenda that recent hurricane activity has been due to global warming.”  Yet no such claims were made.  On the contrary, it was clearly stated that natural variability was dominant in observed the climate record.  Many other mis-statements have been made by Landsea about what was said, and the fact that all statements were carefully caveated.

There are always differences of opinion among scientists on issues of science. NCAR encourages responsible dialog and discussion. But we do not condone name-calling and deliberate attempts to mislead.   The IPCC process is robust, open, and subject to extensive reviews, checks and balances.  We have confidence that it will be balanced and represent the consensus.  However, the process is helped if people contribute rather than withdraw from it.

Updates:
There was a tremendous amount of publicity, often ill-informed, following all of this.  Trenberth remained quiet and did not respond in person to the often personal attacks on his integrity.  Instead he documented the state of the science and the views he espoused at the press conference in this article:

Trenberth, K., 2005: Uncertainty in hurricanes and  global warming. Science, 308, 1753–1754.

Shortly thereafter, two other publications came out which also provided strong support:

Webster, P. J., G. J. Holland, J. A. Curry, and H.-R. Chang, 2005: Changes in tropical cyclone number, duration, and intensity in a warming environment. Science, 309, 1844–1846.

Emanuel, K. , 2005a: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436, 686–688.
—, 2005b: Emanuel replies. Nature, 438, E13, doi:10.1038/nature04427.

And these in turn produced the following article in November 2005

Pielke, R.A., C. Landsea, M. Mayfield, J. Laver, and R. Pasch, 2005: Hurricanes and Global Warming. Bull. Amer. Meteor. Soc. 86, 1571–1575.

The following was a rebuttal by the news conference participants:
Pielke et al (2005) provide their assessment of the situation with regard to hurricanes and global warming.  They state there is "lack of a theory for future changes in storm frequencies" and "the state of understanding of tropical cyclogenesis provides too poor a foundation to base any projections about the future".  Given the lack of any physical understanding of how hurricanes work it follows then that " ...until a relationship between actual storm intensity and tropical climate change is clearly demonstrated,  it would be premature to conclude that such a link exists or is significant ..." .  It is unfortunate that they overlook the considerable understanding and modeling capabilities that do exist in tropical storms, even while recognizing that the theory is incomplete. Indeed, there is plenty of research indicating that hurricanes do respond to the environment in which they are embedded, as summarized by Trenberth (2005).

Observed changes in hurricanes are masked by poor data, especially prior to the 1960s when the satellite era began.  Moreover changes in atmospheric temperature throughout the atmosphere are distorted by changes in radiosondes and instruments. Rising sea surface temperatures and increased atmospheric water vapor provide the primary fuel for tropical convection through latent heat release, and both are increasing.  Atmospheric dynamics play a key role in determining where storms occur and their tracks, and changes are less certain in association with global warming.  But the evidence suggests increases in intensity of storms, once they are formed, and increases in heavy rains and risk of flooding.   The Pielke et al. essay never does discuss the most widespread impact of such storms which is already flooding.

However, the essay also attacks the “misguided” participants in a telecon news conference held to discuss the changes and impacts of the record breaking 2004 hurricane season in Florida.  The transcript  of the news conference has been made available by UCAR (to correct the many misquotes of the statements made at that news conference.  In fact the comments by Trenberth are fully consistent with those in Trenberth (2005).  Pielke et al. further misquote the IPCC (2001).   There is no doubt that social changes of people placing themselves in harm’s way contributes substantially to hurricane damage, but they seriously underestimate the changes in nature that also contribute. But then what should one expect from a bunch of guys who have no expertise in climate change? The article is exceedingly political, and can not even get the strong link between burning fossil fuels and energy and changes in carbon dioxide and atmospheric composition changes right.

Misguided news conference participants (Jim McCarthy, Paul Epstein, Kevin Trenberth).

It was also followed up by this article and response:

Anthes, R. A., R. W. Corell, G. Holland, J. W. Hurrell, M. C. McCracken, and K. E. Trenberth, 2006: Hurricanes and global warming—Potential linkages and consequences. Bull. Amer. Meteor. Soc., 87, 623–628.

Pielke, R., C. Landsea, M. Mayfield, J. Laver, and R. Pasch, 2006: Reply to “Hurricanes and Global Warming Potential Linkages and Consequences”. Bull. Amer. Meteor. Soc. 87, 628–631.

Of course the 2005 season broke so many records that it further demonstrated that global warming was playing a role. 

In January 2007, the AR4 IPCC report was approved in Paris with the following statement in the Policy Maker’s summary (approved unanimously):

There is observational evidence for an increase in intense tropical cyclone activity in the North Atlantic since about 1970, correlated with increases of tropical sea surface temperatures. There are also suggestions of increased intense tropical cyclone activity in some other regions where concerns over data quality are greater. Multi-decadal variability and the quality of the tropical cyclone records prior to routine satellite observations in about 1970 complicate the detection of long-term trends in tropical cyclone activity. There is no clear trend in the annual numbers of tropical cyclones.

And from the Summary of chapter 3 of IPCC:

Intense tropical cyclone activity has increased since about 1970. Variations in tropical cyclones, hurricanes and typhoons are dominated by ENSO and decadal variability, which result in a redistribution of tropical storm numbers and their tracks, so that increases in one basin are often compensated by decreases over other oceans. Trends are apparent in SSTs and other critical variables that influence tropical thunderstorm and tropical storm development. Globally, estimates of the potential destructiveness of hurricanes show a significant upward trend since the mid-1970s, with a trend towards longer lifetimes and greater storm intensity, and such trends are strongly correlated with tropical SST. These relationships have been reinforced by findings of a large increase in numbers and proportion of hurricanes reaching categories 4 and 5 globally since 1970 even as total number of cyclones and cyclone days decreased slightly in most basins. The largest increase was in the North Pacific, Indian and southwest Pacific Oceans. However, numbers of hurricanes in the North Atlantic have also been above normal (based on 1981–2000 averages) in 9 of the last 11 years, culminating in the record-breaking 2005 season. Moreover, the first recorded tropical cyclone in the South Atlantic occurred in March 2004 off the coast of Brazil.

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Well, that may be more than you wanted. But it suggests, at the very least, that this is a complicated matter, no? Would you conclude on the basis of all this, that there was skulduggery against Landsea, who was making valid criticisms of bad science? Oh, of course you might, if that’s the conclusion you want to reach. But I think you’d be hard put (to say the least) to make that case objectively.

Next.

Booker makes a big deal of how glacier retreat on Kilimanjaro has been cited as evidence of global warming. Now, the reasons for the retreat of the ‘snows of Kilimanjaro’ are complex and controversial, and it is ill-advised to use this as evidence of global warming. In this respect, Booker is right to criticize those who do so. But he is wrong and disingenuous to imply that this matter is settled. It’s true that one can pick from the literature to support the contention that the glacier retreat has nothing to do with global warming (and with a handful of incompletely cited works, Booker does just that). But an honest appraisal would force one to conclude that we just don’t know. For example, Lonnie Thompson has just published a paper (PNAS 10.1073/pnas.0906029106 - here) pointing out that, contrary to what Booker claims, the ice retreat on Kilimanjaro had not ‘mostly taken place before 1950’ – on the contrary, the areal extent of summit ice has been decreasing between 1989 and 2007 at more than twice the rate of the decline between 1912 and 1953. Thompson and colleagues present evidence that “the combination of processes driving the current shrinking and thinning of Kilimanjaro’s ice fields is unique within an 11,700-year perspective” (i.e. since the end of the last ice age).

Booker has now commented on this work, as follows:

“In their desperation to keep the panic going before next month's Copenhagen climate conference, the media warmist groupies last week wheeled out, yet again, one of their favourite but long-discredited scare stories, the one about the melting snows of Kilimanjaro. Their excuse was a new study by Al Gore's friend Dr Lonnie Thompson, claiming to show that the ice on Africa's highest mountain is vanishing due to soaring temperatures.

Indeed Kilimanjaro's snow and ice is receding, as I saw for myself when I climbed it a few years back. But, as a small army of international experts have shown, this has nothing to do with global warming (temperatures on the summit, at 19,346ft, never rise above freezing). It has been going on since 1880, due to the decline in precipitation caused by widespread clearance of forests around the volcano's base.

The rate of the ice shrinkage (as I note in my new book on the climate change scare, The Real Global Warming Disaster) was in fact at its greatest in the years before 1950, long before those rising 20th-century temperatures set off the panic over global warming.”

So he dismisses Thompson’s findings without having the slightest argument for why they are wrong – he simply repeats his assertion that the rate of ice loss was greatest before 1950. This puts me in mind of the debate with a creationist that Richard Dawkins records in his new book The Greatest Show on Earth, in which his arguments about the existence of plenty of transitional fossils in museums around the world is met with a mantra-like repetition of dogma.

Indeed, the main reason we are supposed to dismiss Thompson’s findings is that he is ‘Al Gore’s friend’ – I’m not sure I’ve ever seen Booker refer to him as anything else, whereas in reality Thompson is internationally regarded as one of the world’s foremost palaeoglaciolgists. And Booker doesn’t acknowledge that Thompson resolutely avoids firmly ascribing the retreat of Kilimanjaro’s ice to anthropogenic global warming. The paper says that it is difficult to identify the reason for the continued retreat, and acknowledges that precipitation changes  have been implicated (Thompson offers reasons why they are unlikely to be sufficient on their own to account for the trend, however). Thompson also points out that the observed trends are consistent with what has been observed on mountain glaciers elsewhere which are not complicated by such factors. In other words, Thompson lays out his arguments clearly, and stops short of making unjustified extrapolations or interpretations. This is how science is done. Booker just clings to his old story as if to a pole in the wind.

Booker says in his concluding ‘personal note’ that “It is inevitable that such a book will contain errors for which I am solely to blame. But I look forward to the zeal with which they will be picked out and fastened on by hostile reviewers and commentators, claiming that, if I have got this or that fact wrong, then this proves that the whole book can be dismissed as worthless.”  Well no, Christopher, I won’t do that – that is your technique, not mine. However, one has occasionally to raise eyebrows. For example, he claims that “global temperatures in 2007 began that sharp drop which for the first time revealed a distinct gap between the predictions of the computer models that they would continue to rise by 0.3 C per decade, and what was happening in the real world.” And we are now [in the writing of the book] in… mid-2009? So already we know where we’ll end up in 2017? Extraordinary. And then on page 233, Booker claims that “global temperatures’ had experienced a ‘total drop since January 2007” of 7.7 degrees – “a tenth of a degree more than the entire net warming of the 20th century.” Can he be serious? I think he means 0.7 degrees. Bit unfortunate, the way this error seems so alarmingly to support his case. (Actually it wouldn’t, to anyone knowledgeable, who’d recognize that a cooling of this magnitude in so short a time would be unlike anything we’ve ever seen in any climate record ever, and so would have to indicate a process of Armageddon-like proportions.)

Finally, I have just seen Geoffrey Normington’s post on the Prospect site about taking on the climate sceptics. I can’t say I wasn’t warned.