As global growth picks up after the economic crisis, carbon emissions are going back up too. With China and India back on track to double their gross domestic product every decade, and with coal providing nearly 30 per cent of global energy, the chances of stabilising and reducing emissions are low. Indeed, little progress has been made in the last two decades. Only recessions lower emissions – and then only for a short time.

This is partly due to the failed strategy for carbon reduction laid out at Kyoto. But behind it lurks another troubling development: advanced nations fiddling their carbon reduction figures. As Robert Watson, the UK government’s chief environment scientist, has recently accepted, countries such as Britain that appear to have lowered their greenhouse gases have done no such thing. Instead they have exported them, to the developing world. A new approach is now needed to combat this evasion, beginning with plans for carbon border taxes.

The Kyoto agreement tried to get countries to set carbon production caps. These were to be translated into permits, and then traded. Europe led the way with such a system with the US supposed to follow (as soon as President George W. Bush had gone). But the strategy came unstuck at Copenhagen and there is now no prospect of a binding worldwide system any time soon. A US system now looks impossible for years to come, while Australia has stalled, and China and India are not playing ball.