As an antidote to Tony Abbott talking about claimed long term economic benefits of removing carbon pricing to justify its removal, I would suggest people read this post by Michael Tobis and the comments that follow, particularly as to how they relate to economic modelling and climate change.
Tobis has been banging on about this for some time, but it seems to me that not many people pay attention.
I find him quite convincing. Just as I would not expect an economist working in 1913 to have a good set of predictions about the global economy in 2000, even if there was no great intervening issue like climate change, I just do not see how it is plausible to trust modelling that is trying to anticipate economic costs of a 100 year change to climate that will have greatly varying local effects around the globe.
Now, its true: environmentalists use modelling to justify carbon pricing. So how fair is it to criticise the likes of Abbott when he uses economic arguments against carbon pricing?
It is fair, for a couple of reasons: climate change will have much longer term effects than a mere century. Some of those effects that are very plausible/ likely in the longer term are simply obviously disastrous - work out what 2 or 3 m of sea level rise around your favourite global cities is going to do to them, for a start. But on the shorter scale as well, changes to the hydrological cycle are likely to have some very serious effects, and soon, and common sense suggests that they are not readily capable of effective adaptation. The effect will also hit the poorer countries hardest. Have you noticed the flooding in India and China this year? You can only build so many useful dams in a country, even if it is rich. Is there anywhere in Western Queensland you can build a decent drought fighting dam that won't evaporate at a furious rate?
[And even if the unlikely assumption that climate sensitivity is only 1.5 degree for a doubling of CO2, you still have the concern about what ocean acidification is going to do to the food chain in the oceans, with recent work indicating that krill in Antarctica may collapse, and a very uncertain future for pteropods as well. There is no good way to really guess the knock on consequences of the failure of very large elements of ocean food chain like that, I reckon, although scientists are trying.]
Criticisms of economic modelling to show that other economic modelling is flawed therefore misses this whole point. It misses the common sense of the situation.
So ridiculous exercises by small government/libertarian poster boy Topher, for example, are not just a waste of time; they are a dangerous waste of time. At least Greenies who use economics poorly to get to the right political response anyway can't be accused of that.