Friday, 9 March 2007

Climate Deniers vs the Reality-Based Majority

A friend asked for my opinion on a climate change documentary that aired on (UK) Channel 4 last night, entitled "The Great Global Warming Swindle".

For those of you who missed it, the central premise of the show is that we should stop worrying about climate change. The argument used to be that global warming isn't happening. Scientists have now tracked the earth's temperature over the past 800,000 years and proven that argument wrong.

Then the climate deniers argued that if global warming was happening, people weren't to blame. The latest report from the world's leading climate scientists at the Intergovernmental Panel on Climate Change pours cold water on this theory: is extremely unlikely that global climate change of the past fifty years can be explained
without external forcing, and very likely that it is not due to known natural causes alone.

That's pretty strong language for a worldwide assembly of experts working by consensus and prone to quibbling over details.

The next argument was that we may be at fault, but it's too difficult to do anything about it. But the Stern Review commissioned by the UK Government found that it's far more cost effective to reduce CO2 emissions than to do nothing and deal with all the resulting damage.

So did the documentary manage, as the Channel 4 website puts it, "to slay the whole premise of global warming"?

Here's what ("Climate science from climate scientists") has to say about the first claim - that cosmic ray activity is the real cause of global warming:

"...we pointed out that while the experiments were potentially of interest, they are a long way from actually demonstrating an influence of cosmic rays on the real world climate, and in no way justify the hyperbole that Svensmark and colleagues put into their press releases and more 'popular' pieces. Even if the evidence for solar forcing were legitimate, any bizarre calculus that takes evidence for solar forcing of climate as evidence against greenhouse gases for current climate change is simply wrong. Whether cosmic rays are correlated with climate or not, they have been regularly measured by the neutron monitor at Climax Station (Colorado) since 1953 and show no long term trend. No trend = no explanation for current changes."

As for the rest, noted climate expert George Monbiot says it well:

The programme’s thesis revolves around the deniers’ favourite canard: that the “hockey-stick graph” showing rising global temperatures is based on a statistical mistake made in a paper by the scientists Michael Mann, Raymond Bradley and Malcolm Hughes(11). What it will not be showing is that their results have now been repeated several times by other scientists using different statistical methods(12); that the paper claiming to have exposed the mistake has been comprehensively debunked(13) and that the lines of evidence used by Mann, Bradley and Hughes are just a few among hundreds demonstrating that 20th century temperatures were anomalous.

The decision to commission this programme seems even odder when you discover who is making it. In 1997, the director, Martin Durkin, produced a very similar series for Channel 4 called “Against Nature”, which also maintained that global warming was a scam dreamt up by environmentalists. It was riddled with hilarious scientific howlers. More damagingly, the only way in which Durkin could sustain his thesis was to deceive the people he interviewed and to edit their answers to change their meaning. Following complaints by his interviewees, the Independent Television Commission found that “the views of the four complainants, as made clear to the interviewer, had been distorted by selective editing” and that they had been “misled as to the content and purpose of the programmes when they agreed to take part.”(14) Channel 4 was obliged to broadcast one of the most humiliating primetime apologies it has ever made. Are institutional memories really so short?

The basic message from what I call the "Reality-Based Majority" is this:

  • Climate change is real;
  • Our actions are the cause;
  • We need to work together to tackle this problem.
  • The Carbon Clear team is proud to be part of the Reality-Based Majority, and we're glad more of you are joining us.

    (Carbon Clear Homepage)