functioning of the earth system; ensuring that our societies are adequately equipped to withstand the risks and dangers that come from all the vagaries of climate, whatever their cause may be. it explains radical and practical ways to reduce non-co2 human forcing of climate. it argues that improved climate risk management is a valid policy goal, and is not simply congruent with carbon policy. it explains the political prerequisite of energy efficiency strategies as a first step and documents how this can achieve real emissions reductions. but, above all, it emphasises the primacy of accelerating decarbonisation of energysupply. this calls for very substantially increased investment in innovation in noncarbon energy sources in order to diversify energy supply technologies. the ultimate goal of doing this is to develop non-carbon energy supplies at unsubsidised costs less