Climate policy, as it has been understood and practised by many governments of the world under the Kyoto Protocol approach, has failed to produce any discernable real world reductions in emissions of greenhouse gases in 15 years.

The irreconcilable differences between David S. Reay's Book Review of The Hot Topic (Nature 452, 31; 2008) and mine, expressed in Nature Reports Climate Change (see, go to the heart of why there is now a crisis in climate policy. Reay seems to believe that agreement with a normative agenda precludes the need for rigorous evaluation of evidence or of proposed policy actions, and so falls into the same traps as Gabrielle Walker and David King, the authors whom he praises. (Correspondence)

The Kyoto Protocol is a symbolically important expression of governments' concern about climate change. But as an instrument for achieving emissions reductions, it has failed1. It has produced no demonstrable reductions in emissions or even in anticipated emissions growth. And it pays no more than token attention to the needs of societies to adapt to existing climate change.