Sunday, August 03, 2008

No, global heating did not stop in 1998

I am constantly surprised how wrong arguments are repeatedly trotted out in policy debates. They can be relentlessly refuted but, like the weeds in my front lawn, they consistently reappear. Nowhere is this truer than in the climate change debate.

Andrew Bolt claims that climate change stopped in 1998 so that current policies to address it are a waste of effort and money. These claims are comprehensively refuted here in an article by climatologists Robert Fawcett and David Jones.
‘While 1998 was the world’s warmest year in the surface-based instrumental record up to that point in time, 2005 was equally warm and in some data sets surpassed 1998. A substantial contribution to the record warmth of 1998 came from the very strong El Niño of 1997/98 and, when the annual data are adjusted for this short-term effect (to take out El Niño’s warming influence), the warming trend is even more obvious.

Because of the year-to-year variations in globally-averaged annual mean temperatures, about 10 years are required for an underlying trend to emerge from the “noise” of those year-to-year fluctuations. Hence, the fact that 2006 and 2007 were cooler than 2005, is nowhere near enough data to clearly establish a cooling trend’.
Data from three international time series and one for Australia discredit the wrong claims of Bolt. The Garnaut Review commissioned two econometricians at the ANU to examine the same vclaim of a cessation of warming. They also found that the evidence did not support the claim. So too does this study from the Yale Forum.

Bolt rejects the Garnaut findings although he agrees temperatures did rise after 1998 a bit but they have since stabilised. Hardly a compelling counterexample to the case for a continued warming trend given that he is attempting to draw inferences about the long-term trends in climate from a few year’s observations when longer-term trends, and even the short-term evidence, is inconsistent with his claims. It is interesting that one of the institutes he claims supports his views of sustained cooling says no such thing - in fact they forecast a moderation in rates of warming up to 2020 followed by a rapid resumption of warming after this date.

It is tedious to attempt to continue to have to refute the strong evidence of global warming and the case for addressing this problem now. The reason I post this claim is that the shenanigans in the Liberal Party suggest there is still a rump of climate change denialists determined to thwart action on climate change in Australia.

There is no certainty on this issue of climate change but science does not present its claims as certainties. Given that almost all climate scientists accept the reality of warming and that the counter-arguments provided seem so self-evidently weak it seems reasonable on this occasion for non-science citizens to act on the view that waiting for absolute certainty is riskier and more expensive than controlling the causes of emissions now.

1 comment:

Anonymous said...

Harry, the denialists are going to deny the existence of climate change no matter how strong the evidence. They are politically motivated, and the motive appears to be nothing more than a visceral opposition to the environment movement, who were concerned about climate change long before the issue became mainstream. The attitude of people like Bolt is really nothing more than if the greenies believe something to be true, then by definition it must be false.

It's a very immature position but commonplace in political discourse.

And, it must be said, there are those on the left who display exactly the same tendencies. For example, because it has been the Right that it has been most loud in opposition to Islamic terrorists, there are people on the left who claim that it must be a non-problem. There are many examples of such wilful denial on all sides of politics.

Of course there are people on the Right (like you) who don't think like that about climate change just are there people on the Left who can think clearly about terrorism, but the tendency is clear.

But it's just not about politics. Some people are perverse deniers of obvious truths. There are many people who genuinely and sincerely deny that the car accident that killed Princess Diana was an accident; that the moon landings actually did that place; and Elvis Presley really did die at Gracelands in August 1977.

There's no point in arguing with these people. It's not just tiresome. It's pointless.