THE CONTRAST between the hype in the lead up to last year’s Copenhagen climate change conference and the subdued silence which precedes this year’s conference in Cancun in December could not be starker. If Copenhagen collapsed under the weight of inflated expectations, Cancun cannot but surprise on the upside, given that expectations of what it might achieve are already so low.

This is just one illustration of the huge shifts that have taken place in the world of climate change mitigation over the last twelve months. The changes are not unidirectional. Some have been for the better, some for the worse, and some are ambiguous…