Sternly Responding to Stern

There is an interesting ethical debate building up with Professor Paul Collier's response for the economic imperative to tackle global warming (http://www.guardian.co.uk/commentisfree/2009/feb/26/climate-change-ethics-collier). Collier points out that Stern's well-received case is based purely on a Utilitarian argument, namely that the costs of not doing something about global warming now will be dwarfed by the costs to future generations of major climate change. It is hardly remarkable that Stern uses the costs versus benefits approach as this is basically micro-economics. Collier states the possibility that there may be no future generations to benefit is included in some utilitarian models (it would change the calculus). He points out that we don't actually 'own' the planet (and its biodiversity and carbon) but have received it after 'stewardship' from previous generations. He also notes that it is very difficult to do a cost versus benefits analysis on this issue as we don't know how 'rich' people will be in the future (whatever 'rich' means). I can certainly see what Collier is getting at but, as a behavioural ecologist, I am used to the concept that all animals behave in particular fashions when the benefits outweigh the costs. It seems to me unlikely that humans can consistently and collectively operate in another fashion. I hope I am wrong.