If the devil is in the details, climate change negotiators are about to enter purgatory. On Monday, some 2,000 delegates from 162 countries and dozens of specialist agencies open a two-week conference, the first to get into the nuts and bolts of a new global warming agreement meant to take effect after 2012. The meeting builds on a landmark accord reached last December on the Indonesian island of Bali which, for the first time, held out the promise that the USA, China and India will join a coordinated effort to control carbon emissions blamed for the unnatural heating of the Earth.