We can only marvel at the disarray. Here we are, 17 years after the signing of the UN framework convention on climate change, two years after the decision in Bali to agree a new climate policy, one year after Barack Obama's election, and days out from the Copenhagen conference. Yet a real global strategy to avoid catastrophe remains elusive.

Yes, there is some progress. The Obama administration has now offered a 2020 and 2050 target on emissions reduction. China and India have stepped forward with commitments to slow the rise of emissions, and Mexico has tabled creative proposals for climate financing. New technologies offer the possibility of low-cost abatement of greenhouse gas emissions. Through the fog of policy speeches, international meetings and domestic debates, one can...