Politics, otto von bismarck is supposed to have said, is the art of the possible. And one of the most depressing features of discussions about global warming is their tendency to take place in a fantasy land of the politically impossible. Few people in those parts of the world made rich by carbon-dioxide-emitting enterprise are going to volunteer for a cut in living standards. And it is hard to ask those from parts of the world that are not yet rich to sacrifice the chance to become so.

That being the case, it makes sense to concentrate on doing things which affect neither the comforts of the former nor the aspirations of the latter. Technological change that shifts economies away from using fossil fuels as their principal energy sources may be able to achieve this in the long term. But some sort of effective action is also needed now...

The Economist: Those who worry about CO2 should worry about methane, too