 The paper evaluates the impact of climate change on global hydropower generation using an ensemble of simulations from 12 different global circulation models, GCM. The study finds that there will be large variations in changes in hydropower generation across regions and even within regions. While the global hydropower generation is predicted to change very little by 2050, basin-level detailed assessments are necessary for local impacts. The results indicate that climate change will not lead to significant changes in the global hydropower generation at least for the existing hydropower system. This article was authored by Anand Killingfight and Byman Hamadudu.