Sir

Revolutions are often conceived with the best intentions, but so easily claim more than is plausible and more than can ever be delivered. We fear that the “revolution in climate prediction” called for by the World Modelling Summit for Climate Prediction and reported in your journal ('They say they want a revolution' Nature 453, 268–269; 2008) will fall foul of the same hubris.

Any venture bidding for investment that exceeds a billion dollars needs to have well-grounded justifications. Advancing our basic understanding of how the climate system works through enhanced representation of that system in next-generation climate models — (“pure intellectual excitement”) — may indeed be such justification. But claiming that this will allow scientists to “provide answers to key questions ... such as future food supply” and guide decisions the world will be making to cope with climate change displays a misunderstanding of the nature of adaptation and its contingency on our imagining of future social change.

The reason that the UK summit at Reading University over-claimed the benefits of climate prediction for adaptation in its pitch for a billion dollars of new science investment is revealed by the summit's chair, Jagadish Shukla, in his warning: “If we just ask for enhanced understanding, then we have very little chance of getting the necessary funding”.

Effective and robust adaptation strategies are not significantly limited by the absence of accurate and precise regional climate predictions. They are limited more by a multitude of technological, institutional, cultural, economic and psychological factors that lie beyond the reach of climate models — and always will. The epistemological limits to predicting future climates with accuracy and precision must not be used as a reason to limit adaptation to climate change. Bring on the revolution if you will, but don't mistake it for Utopia.