M Batchelor,

You are wrong in trying to set the bar too high for proof of AGW. Scientific proponents of AGW do not say there is "no contest", they say that the evidence is such that the risk of inaction is greater than the risk of action. Obviously, at the political level the message is given in a more simple way because politicians hate to equivocate.

Politicians set policy all the time in the face of uncertainty. Surely we would expect them to use the best advice they can get. If by 2014 temperatures haven't gone up, and there is no reasonable explanation (big volcano, giant La Nina etc.) then they can back-pedal.

quote:

Why do you hope that after you just wrote that it is the long-term trend that is important. The downturn in temperature rate is only until 2010, then there is a 50% probablity of temperature highs above 1998.

Sorry, I wasn't very clear. Obviously I hope that AGW is a huge scientific error. But my reason for hoping that the forecast is correct is because I am peripherally involved (in a non-scientific way) with the model that produced it.

Re. big oil and sceptics, I understand a check of Exxon accounts show that they fund sceptic organisations. I usually avoid discussion of oil-funded lobbyists except when pointing out where a non-expert person is being paid purely as a lobbyist, uses their position to state blatant untruths, and never corrects their information in the face of overwhelming evidence.

And for the record, here's ExxonMobil's response to the 4th IPCC report:

response

I don't get the impression that the big energy multinationals are particularly sceptical about AGW. And even if they are, they at least recognise that any warming (whether AGW or NGW) poses problems for the future, and if they can help do something about it, they are not doing so at the expense of their own interests. It's a no brainer really.

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Originally posted by M Batchelor:
Thanks for your responses, all very good.

Legjoints:

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And we have to face the fact that it's a lot easier for people to be convinced of something they want to believe than for them to be convinced of something they don't want to believe.

That is very true for both sides of the debate. However, it must be remembered that the preson who proposes a theory has more to prove, than the person who finds fault the theory. It's the same as the "innocent until proven guilty" principle. The AGW theory proponent needs to convincingly prove guilt, the AGW theory sceptic just needs to find a single flaw in the case for it to be thrown out. Of course the AGW theory proponent may still change or refine their hypothesis, but not simply declare no contest in order to avoid any critcism.

Science doesn't work in the same way as the legal system. Since it is generally accepted that temperatures are rising there has to be an explanation. If people believe that natural processes are responsible then they have to state which natural processes and they have to produce evidence supporting their claim. Over the years there have been several alternative explanations, but all have fallen by the wayside, having been shown to be false (increase in solar irradience, influence of cosmic rays etc.). The theory that remains, that has a lot of mutually supporting evidence and that has made and is making testable predictions, is that human activity is the main driver of climate change. The IPCC states that they are 90% certain that this is the case. Many scientists felt that the IPCC was too weak, only giving it 90% certainty, feeling it should have been bolder and more certain, but I don't think anyone in the scientific community would declare there to be no contest, or at least no possibility of a contest. There can always be a contest, it just takes someone with a viable alternative theory to step up to the plate and present it.