The book deals with climate change in terms of global warming and its resultant effects on the river flows of Pakistan. Climate change has been identified as the variation in climatic factors occurringfrom causes other than the natural ones. It has been defined world over as the phenomenon ofglobal warming. The impacts of the phenomenon are varied and cover a wide range includingbiological systems, health issues and climatological systems. Out of the various facets of the issue,the focus of study is on the impacts on river flow. How river flow is affected by climate changedepends upon the sources generating the flow. For Pakistan these are snowmelt and rainfall. Theimpact of climate change on these sources defines the effect on river flow. As a result of thewarming, both these factors are being affected.