Over the last 20 years, subsidies for renewable energy sources have been justified by the supposed need to decarbonise the world economy. Decarbonisation was thought to be necessary to curb carbon dioxide emissions and hence to avoid dangerous global warming. However, this argument has lost much of its force in the last three years. The main reason for this development has been the financial crisis and the economic downturn. Environmental concerns have taken a back seat to worries about high unemployment, slow economic growth, huge public debt levels, massive budget deficits and cuts in government spending. To a lesser degree, the global warming standstill over the last 15 years and the growing realisation that an international treaty with legally binding targets for reductions of greenhouse gas emissions will not be achieved have also contributed to the loss of force of the global warming argument. The supporters of renewable energy thus are looking for new arguments to justify subsidies and tax breaks for renewable energy. One new argument is the old claim that fossil fuels are running out. Many people believe this claim, but is it true?