When the science fails, anti-global warming irrationalists resort to meta-arguments. And that’s where the thinking gets really bad.

1) “We’ve had apocalyptic scares before and they never came true” – yes, and the last tests showed no cancer. Doesn’t mean the next won’t. Precedent establishes nothing.

2) “Not all the scientists agree” – yes, and only nine out of ten oncologists think you’ve got cancer and need chemo. But the consequences of non-action mean you have to act now even if it later turns out that you didn’t need to, if you want to maximise your chances.

3) “Maverick scientists have been proved right before” – yes but most such comparisons (Galileo) are about science vs non-science. İn the global warming debate, prometheans play the role of the Pope, denying visible evidence and wittering on about “anti-human nature worship” etc. Every theory has a dissenting opposition – if you took the very fact of dissent as a sign that there was no base for action, then you’re actually opposed to the use of science in human affairs at all, and sheer irrationalism takes over. As many South African HİV+ people are not here to tell you.

4) “Comparisons with societies that destroyed themselves – ie. the Easter İslanders in Jared Diamond’s Collapse – ignore the fact that we have feedback mechanisms to manage our world”. Yes we do – we call it science, and if you ignore what it says is overwhelmingly probable then you’re back on Easter İsland.

5) “The information isn’t all in” – the information is never in. Until, that is, they open up your corpse and go “yep, ıt was cancer” – or, more rarely “no, it wasn’t – sorry the chemo was so rough, but you’re still here. As are the nine other people who did have it, until the chemo got rid of it”.

6) “Doomsday scenarios are pessimistic about human ability” – actually they’re based on the largest collective human scientific endeavour in history – climate change research. What they recognise is that science is two things – episteme, knowledge of the world and techne, skill in manipulating it. The two are not identical – you can know something is going to happen without being able to stop it. İf the oncologist finds pancreatic cancer, you’re going to die. To believe that the very fact we can understand a process means we can deal with it is to go from science to religion – to believe we are not material beings in history, but Gods.

7) “Nature is big enough to absorb whatever we do to it” – recent last resort by many. Argument from precedent again and wrong even there. Bizarrely, advanced most recently by m’esteemed colleague Humphrey McQueen who’s a marxist – a belief that human beings are defined by how they transform nature usually taken as pretty much the core of that system of thought.

8) “Overcommitment to remedying global warming is a diversion of money useful elsewhere” – a category error. If there’s a reasonable chance that global warming is a catastrophic event then money diverted elsewhere would be utterly wasted because we wouldn’t be around to take the benefits of it. Apply the argument to health insurance – “I won’t get it because the money could be used better elsewhere”. Now presume that three of your relatives died of the big C and see if it still seems like a 50/50 choice.

Personally, I believe that honest scientists who doubt global warming should continue to argue against it with all their might – even as we continue to act on the presumption that they’re wrong. And if someone can find three of them who aren’t paid by Exxon, twisted by psychological need then they’ll be doing very well indeed.