Water is going to be one of the key, if not the most critical, environmental issues in the twenty-first century because of the escalation in socio-economic pressures on the environment in general. Any future climate change or climate variability will only accentuate such pressures. This volume initially follows the perspective of the Intergovernmental Panel on Climate Change (IPCC) to infer possible changes in hydrological regimes and water quality based on the outputs from various scenarios of General Circulation Models (GCMs). In subsequent chapters, the possible effects of climate change on the hydrology of each of the continents is examined. The book concludes with an overview of hydrological models for use in the evaluation of the impacts of climate change. It will provide a valuable guide for environmental planners and policy-makers, and will also be of use to all students and researchers interested in the possible effects of climate change.