The ‘cost benefit perspective’ is one reason why the Reagan administration, although generally considered as ‘to the right’ of the GWB administration, at least, in terms of it’s reliance on free market principles, signed the Montreal Protocol on ozone depleting chemicals.

A focus on actual versus imagined results is important too. It’s just not clear when a whole of life, product life cycle analysis is used whether a new Prius is indeed a better choice. You may do better by purchasing a second hand gas guzzler and using the cost differences to buy carbon offset credits.

The insurance approach is not uncommon in other areas of life. Of course “AGW” insurance is collective and communal versus an individual choice. So the concepts don’t map perfectly. Still it is not uncommon for different forms of compulsory third party (CTP) insurance to be imposed by law and the choice of CTP provider to be left to individual consumers. Here in New South Wales all motorists are required to have CTP. I understand some workmen’s compensation regimes work along these lines too. AGW insurance, whether provided as actual insurance or “in kind” via a package of seperate policy provisions, could be imagined as CTP for the planet.