One way or another the US has to be persuaded to take global warming seriously. The fierce argument among Kyoto signatories is how to do it. Cheap fuel is designed into America's unimaginably vast prairies of suburbia without buses or town centres. True, the fashion for four-wheel drive monsters has eaten up all technological gains in fuel efficiency. Since a quarter of the world's carbon output is here, letting America progress at a slower pace makes sense.
Blame is satis fying, but survival depends on results.
It was the detail of this debate that made Prescott storm out of the stalled Hague negotiations in November. He said realism required letting the US cheat a bit by buying spare emissions from Russia and planting forests. Greens said their calculations showed this meant the US need make no other effort at all to change its ways. But getting Americans to accept the idea of fundamental change is the crucial first step. If Kyoto progresses to ratification by all the other countries, the hope is that the US will want to join a carbon emissions trading bloc.