After the Global Warming Policy Foundation’s (GWPF) recent report by Nic Lewis and Marcel Crok (which is discussed in a post by Piers Forster on Ed Hawkins’s blog) there seem to be a couple of conclusions being drawn. Some see it as positive that even the GWPF clearly acknowledge that we will warm and that the amount of warming is not inconsistent with IPCC estimates. Others are pointing out that many climate “skeptics” are actually lukewarmers, and that this report (and the responses) illustrates how they’ve been mis-represented by some. I get the impression that they’re arguing that this report shows that their views are credible and that those who’ve been arguing otherwise, have been unfairly characterising them.
Here’s the problem I have though. As I understand it, lukewarmers are people who believe that the warming will be on the low-end of estimates. It seems that they believe the transient climate response (TCR) will be below 1.5oC and the equilibrium climate sensitivity (ECS) will be below 2oC. Given that the IPCC suggest ranges of 1.0-2.5oC and 1.5-4.5oC respectively, what they believe is possible. However, given the IPCC’s ranges, it’s not particularly likely. It’s more likely that the TCR and ECS will be higher than lukewarmers seem to believe. So, they could be right, but they seem to have simply chosen – for reasons I have yet to fully understand – to ignore huge swathes of evidence that suggest that the TCR and ECS will be higher than they believe.
As far as I can tell, the evidence that they use to ignore other estimates, is that they can’t trust Jim Hansen and Michael Mann – and hence can ignore paleo estimates – and the models didn’t predict the “pause” (which isn’t really a pause), and hence they can ignore model estimates. Given that these are the very people who pontificate the most about scientific integrity, scientific honesty and how science should work, this seems a little pathetic. As I’ve already said, they may turn out to be right, and they’re certainly entitled to believe whatever they want, but they’re not really entitled to ignore evidence just because they want to do so. The idea that everyone should pat them on the back because their views aren’t completely ridiculous, just seems a little absurd.
Having said that, that the GWPF acknowledges that we will continue to warm and that the numbers they present are not inconsistent with IPCC estimates is clearly a positive step. However, I see no reason why this suddenly makes the GWPF, and those who believe these estimates, particularly credible. There is a chance, however small, that they may be right, but science doesn’t work through guesswork, it works by considering all the evidence and weighing that evidence accordingly. As I understand it, that’s what the IPCC does when it produces its estimates for climate sensitivity. Given that, who should we take more seriously, those who choose to ignore large amounts of evidence for reasons that seem to border on conspiracy ideation, or those who consider all the evidence before drawing their conclusions? I know what I think. Maybe others disagree.