If at first you do not succeed, try, try again. Some will dismiss President Barack Obama’s laundry list of steps on global warming as flimsy. Having failed to persuade Congress to pass a cap-and-trade system in his first term, he is retreating to the more modest realm of executive action in his second.

Yet it is hard to see what else he can do. There is scant chance of persuading the 113th Congress to acknowledge man-made climate change, still less to approve tough action to slow it. Modest though they are, Mr Obama’s steps will have positive outcomes. Opponents say he is launching a “war on coal”. Mr Obama should embrace that as a virtue.

Two benefits will come from his order for Environmental Protection Agency regulations to reduce power plant emissions. The biggest will be its impact abroad. At a time of drift in global climate talks, it is good for Washington to be seen to be taking action. Though the US is still the second-largest emitter in the world, its trajectory has been downwards for several years. Partly because of the Great Recession, and partly because of the boom in natural gas, the US is on course to reduce its carbon output to 17 per cent below its 2005 levels by 2020. Yet global emissions keep rising. The most valuable thing the US can do is rekindle a sense of international urgency. The timing is also good when China, and others, are having their own doubts about coal.