The risk of global warming due to an enhanced greenhouse effect became one of the biggest scientific issues in the late 1980s and early 1990s. The United Nations Intergovernmental Panel on Climate Change (IPCC) warned that global temperatures might rise by 0.2° per decade, resulting in major regional changes in rainfall. This book reviews the potential effect of global warming on river flows and water resources. It covers methodologies for climate change impact assessments, techniques for defining credible climate change scenarios, and models for hydrological analysis, before reviewing in some detail the many published studies into possible changes in hydrological regimes. The bulk of the book is built around a case study of the potential effects of climate change for river flows in Britain. The case study is used to illustrate methods and approaches, and is placed in the broadest context through the literature reviews. The book finishes by considering the implications of changes in river flows for water uses and river floodplain activities, as well as for the management of water resources. Nigel Arnell is Reader in Physical Geography at the University of Southampton. He is a lead author of the IPCC Second Assessment of the Impacts of Climate Change and is a member of the UK Climate Change Impacts Review Group. He has led several studies into climate change and its effects on water resources and has advised the National Rivers Authority (now the Environment Agency).