"The climate in the climate conversation has changed a bit." That’s from Germany's environmental minister at the Bali conference on global warming. Yesterday, there was diplomatic bad blood between the US and Europe. Today, the head of the UN's Framework Convention on Climate Change says they're "on the brink of agreement." Andrew Revkin, author of The North Pole Was Here: Puzzles and Perils at the Top of the World, covers the environment for the New York Times.