Bill Clinton is bullish on climate change. “There is way more econ­omic opportunity than cost,” he told the Financial Times. Unfortunately Mr Clinton’s statement is wrong – cutting greenhouse gas emissions will have costs – and while playing down those costs may seem like good politics today, it will not serve Mr Clinton’s cause in the longer run.

In December, at a United Nations summit in Bali, the world’s leaders will begin negotiating a successor to the Kyoto protocol. That deal is crucial. Action to avert the worst effects of climate change cannot be postponed for ever. With Monday’s UN meeting and the Bush administration’s own climate change talks later this week, manoeuvring ahead of the summit is now in full swing.