20100930_R4

Source: BBC Radio 4: Today Programme

URL: N/A

Date: 30/09/2010

Event: Justin Webb interviews the Royal Society's Professor John Pethica.

People:

• Tom Feilden: Science correspondent, BBC Radio 4 Today programme
  • Professor John Pethica: Professor of material science and Fellow of the Royal Society
  • Justin Webb: Presenter, BBC Radio 4 Today programme

Justin Webb: The Royal Society, representing the cream of British science, has launched a new guide to climate science. Some have complained that previous guidance was a little too strident. In a moment, Professor John Pethica, who chaired the working group that wrote the new document. But first, a word from our science reporter Tom Feilden. Now Tom, I suppose the key question is: what's changed?

Tom Feilden: Yes, it's an attempt, I suppose, by the great and the good of the scientific community, in the shape of the Royal Society, as you say, to draw a line under all the recent controversy over climate change. A position statement, if you like, about what we know, what there's strong consensus about, and where there's uncertainty about the science or what it's telling us about the climate. And the conclusion, I have to say, is pretty stark. The report concludes: there is strong evidence that changes in greenhouse gas concentrations have warmed the planet since 1850 and will continue to do so, and that the dominant factor in those changes causing global warming is down to human activity.

Justin Webb: But what about the effects that that might have?

Tom Feilden: Well, it certainly is less strident, if you like, I think that's probably the right way of putting it, about those impacts, I mean. The previous report, published three years ago, was, as we say, a little too strident for some of the Royal Society's fellows to sign up to, if you like. That came in the light of a Channel 4 documentary setting out the sceptics' case, and really was a point-by-point rebuttal of those arguments. The Society insists this review would have happened anyway, but it is much more measured in terms of the language used, although as I say the conclusion is pretty much the same. Even so, it has been welcomed by one of the leading sceptics I spoke to, Dr Benny Peiser from the Global Warming Policy Foundation, last night, who described it as a clear improvement that took account of the uncertainties and accepted that some questions, particularly about the likely impacts of climate change, were still open. So a less political, more sober document.

Justin Webb: Tom, thank you. Well, as I say Professor John Pethica, who helped write - oversaw the writing of the new document - is on the line now. Good morning to you.

John Pethica: Good morning.

Justin Webb: Is this a climb-down?

John Pethica: No. The science, as your correspondent has just pointed out, remains precisely the same.

Justin Webb: But you have altered what you say about the potential impact of that science.

John Pethica: Well, let me stress, this document really discusses the science of climate change. That's how it works, the processes that lead to it, that's its primary focus. And it's aimed really at trying to give a full, broad spectrum of the status of the science in the subject at the moment.

Justin Webb: But the fact is that you had a document, and you've altered it, and from what we've been hearing from Tom Feilden, the effect of the alteration seems to be, to some extent, to water down at least the certainty of the things that you were saying.

John Pethica: No that's not actually the case. In fact there are many documents that have been published on this subject matter, by both the Royal Society and indeed many other academies throughout the world. And you can find all those on the websites, so that's not, in any sense, disappeared. What this document tries to do is to set out in a concise accessible manner, the full spectrum of issues that actually concern climate science itself, and of course that involves uncertainties, and indeed this document is structured in such a way as to make clear what those uncertainties, and also what the certainties are -

Justin Webb: Yes, so at least in that sense, you would accept, would you, that the previous document was too certain, and that this document reflects that.

John Pethica: No actually, if you'll look at the science, you'll find it's exactly the same -

Justin Webb: I'm struggling to know what's changed, then.

John Pethica: The way - this document is aimed at a presentation which gives you the whole story. As your correspondent just pointed out, then of course, that was a document that pointed to specific, technical points that were raised in a particular programme. This one gives you the whole story. And of course, that involves the certainties and the uncertainties.

Justin Webb: And in doing so, plainly you have had some sceptical, or at least agnostic I suppose would be a better word to use, fellows of the Society who were worried about what was being said before. Does this mean now, that whenever you issue any kind of guidance on this subject, you're going to have to take into account their views, even though they are, I think it's fair to say, quite a minority in the organisation?

John Pethica: That would be a fair comment, your latter comment. But in fact the process of reviewing anything in science always involves extensive cross-checking of views, I mean, whether it be within a specialised subject or a more broad issue. And in fact if you look at any of the Society's reports which have been made in recent years, you'll find that the composition of the panels involved not only experts, who of course you have to have, people who really understand the science and the great detail that's led up to the current position, but also people who can give a different perspective. There are plenty of examples of that, for example the one I was involved in years ago on nanoscience, for example, that involved people with different views. You will see that in our present report.

Justin Webb: Yes, so you would accept that previously there weren't enough perspectives involved, and that there are now.

John Pethica: Well, I suppose you could put it that way, but the reality is that there are always many perspectives involved - individuals have their own views.

Justin Webb: Does this draw a line under the whole issue, because there were complaints, weren't there, and you had to deal with some degree of internal debate within the Society, and a sense that the original document, the 2007 document, didn't do justice to the totality of what was going on? Do you hope now that that issue at least is put to bed?

John Pethica: In the sense that we're now addressing the whole totality of the subject in a compact document, that's true. But of course that's been available for a long time, you know, the IPCC report itself is a version of that, it's just several thousand pages. This is just a few. The other important point to stress, however, is that debate is always part of the process within science. It would be rather strange, in fact, if you had a situation where we agreed on everything and we go away and do something else. There's always going to be debate in this process, and on this subject we have discussion meetings, for example there's been two this year. You expect debate, you expect contention, that's how science works.

Justin Webb: Yes, you do expect debate, but on the other hand people need to know and want to know whether or not there is something like a consensus or unnanimity on certain very important subjects, and in the past it's certainly true that at the top of the Royal Society, people were very very certain that on the one hand, and to quote Lord May, the former boss, on the one hand you have an entire scientific community, and on the other hand you have a handful of people, half of them crackpots. And it sounds to me as if that what you're suggesting now in this report, is that sort of didactic view from the top no longer really holds.

John Pethica: No, that's not correct. What we've done here is we've taken into account all the scientific evidence that's available at the moment and summarised it, so in that respect, this report serves two purposes. One is to allow the public at large to see, or help them see, what the scientific consensus is, which is the point you've just made, but I should stress, this is based on the scientific evidence, this is not a matter of just adding up a load of opinions. This is actually analysing whether things make sense or not. And you will observe that the science has remained precisely the same.

Justin Webb: Professor John Pethica, thank you very much.