It is fairly clear to me from having worked for years in the environmental
policy field that what science says or does not say about global warming and
its impacts is largely irrelevant when it comes to deciding what, if
anything, to do about it. Because, in the opinion of most decision-makers,
reducing greenhouse gas emissions would result in an unacceptably high
socio-economic hit, it will never happen. Letting global warming take place
and adapting to its impacts is, in the view of many policy-makers, much more
acceptable and can result in net socio-economic benefits for current
generations. If science were a consideration, we would make a concentrated
effort instead to reduce emissions now in such a way as to minimize the
current hit, with a view to achieving intergenerational equity. Basing
decisions on socio-economic analysis will never result in significant
reductions because, among other things, of the enormous effect of
discounting a benefit stream over a century or so. The irrelevance of
science was highlighted when the global and national emission reductions
targets were set in Kyoto - the over all reduction target and the individual
national targets were not based on science but on political negotiation with
countries' positions being driven by socio-economic considerations.

The bottom line - move away from policy discussions based on science and the
resulting scientific "debate", which that detract us from examining what
needs to be done to ensure sustainability of our socio economic systems in
the long term. This includes, of course, sustaining the earth's life support
systems, without which socio-economic activity cannot exist.