The Climate Files

Last week, while on travel I had a chance to read Fred Pearce's recent book on the East Anglia emails (pictured above). After reading the book, rather than doing a conventional review, I decided to approach Pearce about doing an interview with me. Pearce responded promptly and graciously. Below you can see my questions and his answers.

1. Are you a "climate skeptic"? How would you characterize your views on climate change science and politics?

A: I am skeptical in, I hope, the best sense. Skeptical but not cynical. Skeptical in the sense of questioning. I think that those who actively question the mainstream story from climate scientists have done us a good turn by arguing, correctly, that those scientists know less than they sometimes claim, or imply. There are huge uncertainties in predicting the impact of the "greenhouse effect" on climate, some of them not encapsulate in the models. Some people have been less than honest about that. The tide may be changing, however. I predict that the next IPCC report will have wider error bars than the last one. The more we know the less we seem to know for sure.

Where I think some critics of the IPCC are wrong is in concluding that, because we know less than we think, we need not worry. I think we need to worry more. High-impact low-probability outcomes are a real concern. That is why a book I wrote a few years ago (With Speed and Violence) that was subtitled "why scientists fear tipping points in climate change."

However we arrange it, we have to break our addiction to carbon-based fuels. Even if we have not got our estimates of climate sensitivity quite right, at some point we have to kick the habit. Let's get on with it. The key will be technology. I am optimistic we can do that, but unclear about the combination of forces (cultural, ethical, political, economic) that will get us there. There are likely to be tipping points in technological development as well as in the natural system, and I just hope we reach ours before nature reaches its.

2. The issues surrounding the East Anglia emails involve an incredible amount of "he said-he said" and your book seeks to cut through some of these contestations. How important is it for people to understand the various arcane details of these disputes? Is it possible to determine who is right and who is wrong in these debates?

A: Not important at all, except for people who want to. I wrote the book because I was in a position to, knowing the background to some of the issues, knowing many of the individuals concerned, and (being a freelance) having the time to devote to it. I also felt that a lot of rubbish was being talked both by those keen to use the emails to trash the scientists and by the defenders of the scientists. I thought an old-fashioned journalistic investigation could be useful.

I also had a sense that some times in the past I had no paid sufficient attention to what some "skeptics" were saying, and i personally needed to explore their arguments in a bit more depth. Some of the details are arcane, and many are not amenable to simple right-and-wrong answers. One of the advantages of doing a book-length study is that you can reflect that better. Nuance is a luxury in a thousand-word news story that rarely survives editing. And of course who is judged right or wrong may depend on your perspective (moral, temporal and others). You can reflect that, too. Where I felt people were hiding things or telling very partial truths, i said so. Where I felt there were simply different interpretations, I said that, too.

3. No one in your book comes across as a particularly sympathetic character. You are extremely scathing about "the skeptics" and have little sympathy for the scientists in the emails. What does this say about debate over climate change?

A: I suspect that many of the actors in the story got to the point where they simply couldn't see anything other than bad motives among their antagonists. Climategate was a tragedy of mistaken motives. So, to take one example, the emailers often saw Steve McIntyre as a hostile, politically motivated climate denier, when he was actually a data libertarian of a broadly "lukewarm" persuasion. McIntyre tended to respond by seeing them as having something to hide, when often they didn't. The debate got rancid. Many people were being forced to take sides when they did not want to. "If you aren't for us you are against us."

I think the release of the emails and the fallout that has followed, while unfair to some individuals caught up in it, will result in a much more open and candid debate about climate science in future.

4. In some places in your book you identify who was right and who were wrong in particular scientific debates. How well prepared are reporters to render such judgments and are you confident that yours have held up?

A: Reporters back off such judgments. Often out of journalistic convention more than anything. There was a long piece in the Columbia Journalism Review looking at the version of the investigation we ran in the Guardian newspaper here in the UK back in March. The piece remarked in favorable terms on how we were more willing than US reporters (and journalists in general, I would say) to call a lie a lie. To take one example, it seemed to me inconceivable that Senator Inhofe did not knowingly mislead in his remarks about the "hide the decline" quote. His interpretation was entirely inconsistent with the timing of the email he was discussing. So I said so.

Of course columnists and op-ed writers are generally free with their conclusions (including those about the motives of people they write about), but they rarely trouble to marshal the kind of evidence to make it stick. That's the virtue of investigation. If you do an investigation you shouldn't back off conclusions when they are logically inescapable. Yes, I am confident mine have held up. But I am happy to admit error where it occurs. After the original Guardian articles we invited readers (including participants in the story) to annotate a version we put online, and those corrections and criticisms (along with some others that reached us by other routes) were incorporated in the book version, either as revisions or quoted as new perspectives.

5. You assert that Kevin Trenberth was subject to attacks based on his views of hurricanes akin to those experienced by Mann and Santer. As a participant in the debates over hurricanes I saw no systematic attacks on Trenberth such as those Santer and Mann faced. Arguably, Trenberth was giving better than he was getting -- did I miss something?

A: Trenberth took a lot of flack, particularly around the time of Katrina. I agree he gave some out, too. Not much is systematic, I guess. I generally subscribe to cock-up theories of history rather than conspiracy. Stuff happens, as someone once said. The main difference is that it mostly happened within a few months, whereas the attacks on Santer and Mann have been going on for years. They were often also more loaded with political baggage (as were some of the responses, as we saw in the emails).

Judy Curry has argued that the "hurricane wars" were resolved within a few months (or at any rate became civil discussions) because the scientists involved were willing to talk to each other. Whereas in particular the hockey stick dispute has persisted for more than a decade because they were not. I think there is probably some truth in that. As an aside, I notice that Trenberth is now becoming an apostle for discussions about scientific uncertainty.

6. If the big picture of a human influence on climate is not implicated by the emails, why should anyone care about this episode? At one point you call everything else a "sideshow".

A: Maybe they shouldn't. But they did, and I thought it needed serious investigation. If I wasted my time, so be it. However, I think there were substantial issues raised about scientific process and integrity -- about sharing data, about responding to FoI requests, more generally about how science handles FoI, about conflicts of interest in peer review and IPCC report writing, about declaration of interest, about the transparency of the IPCC process. On the IPCC front, many of the points are taken up in the recent InterAcademy Council report.

The saga shows that the debates about the hockey stick remain unresolved (even Phil Jones agrees on that now). But to me it is a sideshow whether the 11th century was as warm as the 20th century. We know there is natural variability. If we can use that to assess the sensitivity of climate to greenhouse forcing, that is useful, but the actual temperatures in the 11th century seems to be of little account. (I might say that I have always argued this, including at points where the IPCC seemed keen to use the hockey stick as some kind of confirmation of man-made global warming.)

7. Can you point to the specific work by Daniel Nepstad that justifies the IPCC claim that "40 percent of the Amazon forests could react drastically ..."? I looked into this and found no such statements in any of Nepstad's (or anyone else's) work. You claim otherwise. What have I missed?

A: I took a fresh look at this. In a statement here:

http://www.whrc.org/resources/essays/pdf/2010-02-Nepstad_Amazon.pdf

Nepstad himself says the 40% claim is correct. He cites two of his own papers:

Nepstad, D., P. Lefebvre, U. Lopes da Silva, J. Tomasella, P. Schlesinger, L. Solorzano, P. Moutinho, D. Ray, and J. Guerreira Benito (2004), Amazon drought and its implications for forest flammability and tree growth: a basin-wide analysis, Global Change Biology, 10, 704-717.

Nepstad, D., I. Tohver, I., D. Ray, P. Moutinho, G. Cardinot. 2007. Mortality of large trees and lianas following experimental drought in an Amazon forest. Ecology88(9): 2259-2269.

The latter found a “38 percent increase in mortality” from a simulated drought in a large-scale forest experiment. That seems reasonable justification for the “up to 40 per cent of the Amazon forests could react drastically,” though one might quibble with Nepstad’s assertion that it substantiated the words about this being the result of “even a slight reduction in precipitation.” In the context of the IPCC's word "could", maybe it does. It is arguable.

I also based my summary of the state of affairs on two Met Office papers:

PM Cox et al, 2004. Amazonian forest dieback under climate-carbon cycle projections for the 21st century. Theoretical and Applied Climatology, 78, 137–156. DOI 10.1007/s00704-004-0049-4

RA Betts et al, 2004. The role of ecosystem-atmosphere interactions in simulated Amazonian precipitation decrease and forest dieback under global climate warming. Theoretical and Applied Climatology, 78, 157–175. DOI 10.1007/s00704-004-0050-y

The former predicts a drop in broadleaf tree cover from 80% to 28% between 2000 and 2100 as a result of a combination of climate change (including reduced precipitation) and resulting carbon loss from soils. The latter predicts a reduction from 80% to “less than 10%” by the end of the 21^st century, with strong feedbacks between the carbon cycle and reduced precipitation. Both therefore suggest changes far in excess of a 40% loss.

You might reasonably say Nepstad’s “later work” does not fully justify the IPCC statement, even if Nepstad says it does. Though I think it goes a long way. But the Cox and Betts work (both carried out at the UK Met Office) do seem to justify it, especially as it only says “could."

I agree I could have been harder on the IPCC at this point. I have no desire either to support or denigrate the IPCC text which, I suggest, might have been better composed. In any event, I wished to save my criticism for rather more clear-cut indiscretions.

8. In your book you call me a climate skeptic in several places. On what basis?

A: I used the term loosely. Carelessly, you might say. I might have distinguished between those who are "skeptical" about the climate science and those who are skeptical about the policy conclusions being drawn from it. Would I be right to put you in the second category? Maybe the term is more loaded in the US than the UK. I sometimes call myself a "skeptic in the best sense." But in general I don't like giving people labels they are personally unhappy with, without justifying them. So I regret that term in your case.

9. You say that perhaps journalists hadn't done their jobs. What does this mean and what should they be doing differently?

A: Journalists, under pressure of time and their editors, rarely read the emails before writing their stories. They essentially reported what was being said about the emails. And did so uncritically. Mostly, they didn't report the emails themselves at all, other than using the quotes culled from them by protagonists. I think this is bad journalism. We should have a mission to explain. Often we lose sight of that. I should stress than I do not have daily deadlines (or not every day, anyhow). So this is easy for me to say. But we should do more digging and more truth finding.

10. Finally, you say that the scientists created "two tribes." Yet, your book is full of language that divides the world into "the skeptics" and the scientists, and their associated allies. How would you characterize the climate debate?

A: Yup, probably guilty. But if people insist in lining themselves into two camps, it is hard not to report them in that light. I did then try and get beyond that caricature in discussing the substantive issues. Before the release of the emails, the climate debate had become polarized. Among mainstream scientists in particular it became hard to criticize any aspect of the mainstream story -- as portrayed in IPCC reports and the "Copenhagen process" without being labeled as somehow a wrecker, skeptic or even denier. This was unhealthy. It created the climate in which some parts of the IPCC assessments (notably parts of the working group 2 report on impacts) became occasionally unbalanced -- as highlighted in the InterAcademy Council report.

I genuinely believe that some of the poison has been removed in the past year.