Tim Lambert links to this article by Eric Pooley in Slate’s The Big Moneye which points out that, for all the disagreement among economists regarding the details of climate change policy, there is substantial consensus on the following main points
(i) the cost of action to stabilise atmospheric concentrations of CO2 and other greenhouse gases will be of the order of 1 per cent of GDP
(ii) a strong mitigation policy is preferable to business as usual
There is also widespread, though not universal, support for the view that it is best to act early and strongly rather than waiting for more information.
The article makes the point that the quarrelsome nature of economists obscures the level of consensus and that has certainly been my experience.
Also from experience, I know that quite a few readers of this blog are unwilling to believe that (i) can be right. But the argument from personal incredulity is not a sound basis for reasoning. It’s easy to check that the cost can’t be much more than 10 per cent of GDP (about five years worth of economic growth), which contradicts the common intuition that cheap energy is economically vital. Once you accept that upper bound it seems silly to disagree with the experts on the best estimate in the range 0-10.