Stoat, the blog that has abandoned science in favour of economics, about which I know little. But wait for the musing post on model skill scores…
Anyway, the last post got lots of interesting comments – thank you – dear reader, go take a look if you don’t normally read post comments. I shall pick up on a few of them…
The main issue is how much interaction should there be between economics and climate folk in constructing CO2 scenarios.
Currently, the IPCC (and many modelling groups) use the SRES scenarios. Or rather, in practice, only a few of the many scenarios. I (and possibly they, if pushed) would justify this by the scale-to-CO2-not-time argument (this is pretty well admitted by the practice of using much simpler models to interpolate between scenarios), but it has to be admitted that if you care about T rise at a given time this leaves something to be desired. SRES are constructed by… well I don’t know. I’m pretty sure lots of them are economists, since they are capable of saying things like “PPP” and sounding sensible. So I think that economists *are* involved in producing SRES. Maybe not the right ones? Some people clearly feel left out.
There are plenty of other scenarios out there but I don’t think many people bother with them. In some ways this is a fight for mind-share.
There is (as far as I know) little or no impacts-of-climate-change on the scenario economics – which was my reason for saying keep the econ and the sci separate. However, perhaps thats rather backwards looking: JA may be right to point out that you *expect* climate change to impact society, or else, errr, why are you bothering?
Some of the models are run with bio feedbacks – HadCM3s famous dieback of the amazon, for example. But these are (I think) only natural feedbacks. There is no “increased T in the tropics leads to more air conditioning but inc T in the poles leads to less heating” stuff in there. And thats only the bleedin’ obvious sort of econ feedback (less sea ice in the Arctic saves on fuel costs for shipping?). So perhaps there should be some economists involved in building feedbacks into the model? Perhaps, but thats not the same thing as scenario development. But I suspect that a model with those kind of feedbacks in would be rather hard to build well.
All in all I’m still somewhat dubious about the useful scope for clim/econ interaction… but maybe I’m just being fuddy-duddy. I’m also somewhat dubious about the value of this pile of ramblings, but since I’ve written it I’ll post it anyway :-)