Guardian: Yesterday, George Bush made another faltering step on the long road to accepting that the US should do something about its contribution to global warming. From outright denial of the science, and deep scepticism about targets and timetables, he has moved on and now accepts that something must be done. He even announced yesterday what sounded like a firm commitment: “I am announcing a new national goal: to stop the growth of US greenhouse gas emissions by 2025”. I suppose …