The effects of future climatic changes on international water resources: the Colorado River,the United States,and Mexico

International water resources have been a source of contention in many parts of the world over the last few decades and such conflicts may grow in frequency and severity as future climatic changes alter the quantity or quality of limited water resources. Indeed, some future climatic changes appear inevitable due to growing atmospheric concentrations of carbon dioxide and other trace gases. Unless mechanisms for incorporating climatic changes into water agreements can be worked out, these changes may provoke further frictions and conflicts. One region with a history of political conflict over shared water resources is the Colorado River Basin in the United States and Mexico. While past disagreements over water have mostly been resolved, future climatic changes that adversely affect the existing hydrologic regime of the basin cannot be discounted. This paper examines the possibility that future long-term climatic changes may exacerbate shortages in the Colorado River. Political conflicts and tensions that arise from reductions in water supply in both the United States and Mexico are evaluated and discussed, together with recommendations for incorporating the issue of climatic change into existing international treaties and agreements.