With its references to raging storms, icy currents and gathering clouds, the weather featured heavily in Barack Obama’s first inaugural address. He even promised to do something about it – “to roll back the spectre of global warming”. And he tried. Of his three big first-term reforms, including healthcare and Wall Street, only cap and trade failed. It still damaged his party in the midterm elections. Realists say it would be suicidal to try it again. But inaugurations are meant to lift our gaze to the horizons. Overhauling immigration and curbing gun violence are worthy goals. But neither compares to the health of the planet.

Mr Obama has in fact been “thinking long and hard about climate change” since the election, according to a senior administration official. Most of his advisers are counselling modesty. Here are three reasons why the US president should risk vituperation – and even ridicule – by aiming high. First, kids will lie down with leopards before Washington turns bipartisan again. No matter what Mr Obama does – whether it is a plan to subsidise hula hoops or a long walk in the woods with Iran’s Ayatollah Khamenei – he will be opposed by a majority of Republicans. He should risk his capital on something game changing.

Second, the reality of global warming is starker today than four years ago – in most respects, alarmingly so. The last report by the Intergovernmental Panel on Climate Change came out in 2007. Subsequent temperature rises, the speed of the retreat of summer Arctic ice coverage, and the increase in extreme weather events, makes clear that its forecasts were conservative rather than alarmist. In spite of La Ni?a, the weather phenomenon that cools temperatures in the Pacific, 12 of the 14 hottest years on record since 1880 have been in this century. Each of the past 36 years has exceeded the 20th century average.