The potential impact of global warming on water resources is of major national and international concern. This book draws together research work aimed at providing global and regional syntheses of the likely hydrological effects of climate change over the coming century. The chapters range from assessments at continental and sub-continental scale, to the development of new methodological approaches for down-scaling climatic predictions, analyses of recent trends in hydrometric data, and reviews of ongoing research on regional hydrological impacts. Although it is still early days for climatic impact prediction, the book demonstrates considerable unaniminity in its general conclusions.