Nicholas Stern: Calculating the Cost Of Climate Change

He doesn't look like a rock star, but nowadays he gets to hang out with some of them. And when politicians want answers to the world's most pressing economic dilemmas, he's the headline act. For three years, Nicholas Stern has been the top economist at the British Treasury, a job usually calling for faceless brilliance devoted to economic stability. But Stern's tenure has been different: he has overseen two major reports for Prime Minister Tony Blair designed to make the world see tough problems anew. Last year's Africa Commission, an idea hatched by Irish rocker and Africa advocate Bob Geldof, brought African leaders together with those from Europe, Asia and the U.S. Stern's report on its conclusions — that the continent could tackle poverty by cutting corruption, investing in health and education and stopping regional wars — helped motivate rich countries to double African aid.

Two months ago, Blair unveiled Stern's next opus, which he called "the most important report on the future published by the government in our time in office." It argues that humanity will find it much cheaper to make slight shifts in energy use now (equivalent, Stern estimates, to a 1% tax on current consumption) than risk the potentially huge costs from unchecked climate change decades from now. The report was a major hit, gaining cross-party support and media attention across Europe.

Stern is now on a global road show selling his climate proposals, after which he'll return to the London School of Economics. The advice he is giving politicians worldwide is unambiguous. "We must act together," he says, "and we have to act quickly."