Wednesday, March 18, 2009

The right honourable Nigel Lawson

At a university talk I gave recently, a member of the department suggested that I might look at Nigel Lawson’s book An Appeal to Reason: A Cool Look at Climate Change. It’s not that Lawson is necessarily right to be sceptical about climate change and the need to mitigate (rather than adapt to) it, he said. It’s simply that you have to admire the way he makes his case, with the tenacity and rhetorical flair characteristic of his lawyer’s training.

And as chance would have it, I soon thereafter came across some pages of Lawson’s 2006 essay from which the book sprang: ‘The Economics and Politics of Climate Change: An Appeal to Reason’, published by the right-wing think-tank the Centre for Policy Studies. (My daughter was drawing on the other side.) And I was reminded why I doubted that there was indeed very much to admire in Lawson’s methodology. There seems nothing admirable in a bunch of lies; anyone can make nonsense sound correct and reasonable if they are prepared to tell enough bare-faced fibs.

For example, Lawson quotes the Met Office’s Hadley Centre for Climate Prediction and Research:
“Although there is considerable year-to-year variability in annual-mean global temperature, an upward trend can be clearly seen; firstly over the period from about 1920-1940, with little change or a small cooling from 1940-1975, followed by a sustained rise over the last three decades since then.”

He goes on to say: “This last part is a trifle disingenuous, since what the graph actually shows is that the sustained rise took place entirely during the last quarter of the last century.” No. The quote from the Hadley Centre says it exactly as it is, and Lawson’s comment is totally consistent with that. There is nothing disingenuous. Indeed, Lawson goes on to say
“The Hadley Centre graph shows that, for the first phase, from 1920 to 1940, the increase was 0.4 degrees centigrade. From 1940 to 1975 there was a cooling of about 0.2 degrees… Finally, since 1975 there has been a further warming of about 0.5 degrees, making a total increase of some 0.7 degrees over the 20th century as a whole (from 1900 to 1920 there was no change).”
Right. And that is what they said. Lawson has cast aspersions on grounds that are transparently specious. Am I meant to admire this?

It gets worse, of course. Carbon dioxide, he tells us, is only the second most important greenhouse gas, after water vapour. Correct, if you don’t worry about how one technically defines ‘greenhouse gas’ (many scientists don’t usually regard water vapour that way). And your point is? My point is that we are not directly pumping water vapour into the atmosphere in a way that makes much difference to its atmospheric concentration (although anthropogenic warming will increase evaporation). We are doing that for carbon dioxide. What matters for climate change is not the amounts, but whether or not there’s a steady state. Who is being disingenuous?

“It is the published view of the Met Office that is it likely that more than half the warming of recent decades (say 0.3 degrees centigrade out of the overall 0.5 degrees increase between 1975 and 2000) is attributable to man-made sources of greenhouse gases – principally, although by no means exclusively, carbon dioxide”, says Lawson. “But this is highly uncertain, and reputable climate scientists differ sharply over the subject.”

What he means here is that a handful of climate scientists at professional institutions disagree with just about all the others everywhere in the world in maintaining that the warming is not anthropogenic. ‘Reputable’ scientists differ over almost everything – but when the difference is in the ratio of 1 to 1000, say, who would you trust?

And then: “the recent attempt of the Royal Society, of all bodies, to prevent the funding of climate scientists who do not share its alarmist view of the matter is truly shocking.” No, what is truly shocking is that Lawson is so unashamed at distorting the facts. The Royal Society asked asked ExxonMobil when it intended to honour its promise to stop funding lobby groups who promote disinformation about climate change. There was no suggestion of stopping any funds to scientists.

“Yet another uncertainty derives from the fact that, while the growth in manmade carbon dioxide emissions, and thus carbon dioxide concentrations in the atmosphere, continued relentlessly during the 20th century, the global mean surface temperature, as I have already remarked, increased in fits and starts, for which there us no adequate explanation.” Sounds pretty dodgy – until you hear that there is a perfectly adequate explanation in terms of the effects of sulphate aerosols. Perhaps Lawson doesn’t believe this – that’s his prerogative (although he’s then obliged to say why). But to pretend that this issue has just been swept under the carpet, and lacks any plausible explanation, is utterly dishonest.

But those mendacious climate scientists are denying that past warming such as the Medieval Warm Period ever happened, don’t you know: “A rather different account of the past was given by the so-called “hockey-stick” chart of global temperatures over the past millennium, which purported to show that the earth’s temperature was constant until the industrialisation of the 20th century. Reproduced in its 2001 Report by the supposedly authoritative Intergovernmental Panel on Climate Change, set up under the auspices of the United Nations to advise governments on what is clearly a global issue, the chart featured prominently in (among other publications) the present Government’s 2003 energy white paper. It has now been comprehensively discredited.” No. It has been largely supported (see here and here). And it was never the crux of any argument about whether 20th century climate warming is real. What’s more, it never showed that ‘the earth’s temperature was constant until the industrialization of the 20th century; the Medieval Warm Period and the Little Ice Age are both there. As you said, Mr Lawson, we’re talking here about relatively small changes of fractions of a degree. That, indeed, is the whole point: even such apparently small changes are sufficient to make a difference between a ‘warm period’ and a ‘little ice age’.

Phew. I am now on page 3. Excuse me, but I don’t think I have the stamina to wade through a whole book of this stuff. One’s spirit can only withstand a certain amount of falsehood. Admirable? I don’t think so. Imagine if a politician was caught being as dishonest as this. No, hang on a minute, that can’t be right…

I’m moved to write some of this, however, because in the face of such disinformation it becomes crucial to get the facts straight. The situation is not helped, for example, when the Independent says, as it did last Saturday, “The melting of Arctic sea ice could cause global sea levels to rise by more than a metre by the end of the century.” Perhaps there’s some indirect effect here that I’m not aware of; but to my knowledge, melting sea ice has absolutely no effect on sea level. The ice merely displaces the equivalent volume of water. We need to get this stuff right.

No comments: