The Water Cycle, Climate Change, and (Some of) Their Interactions

This note is assigned in Darden's course elective, "Global Economics of Water." There is more than enough fresh water to satisfy the world's needs. The primary concern, however, is the geographical mismatch between water needs and the availability of water to communities who need it. Hence, a major challenge for the 21st century is to better manage this mismatch. In this note, we focus on one particular factor—climate change—and how it may contribute to future stress on water resources. We lay out the basics of climate change and the hydrological cycle, and we point to some of the intricate ways in which both phenomena are connected. This note does not contain blanket policy recommendations as to how to fight global warming beyond the general statement that the rational response to the risk and uncertainty of higher global temperatures and their associated environmental changes is to take actions that ensure against potentially adverse effects. Excerpt UVA-GEM-0118 Feb. 19, 2014 The Water Cycle, Climate Change and (some OF) their Interactions The world is not running out of water. There is more than enough water to satisfy the world's needs. The primary concern, however, is the geographical mismatch between water needs and the availability of water. Hence, a major challenge for the 21st century is to better manage this mismatch. The availability and use of water is determined by many factors. Discussions about future water scarcity reflect worries about a growing world population, its increasing affluence, and the lifestyle and dietary changes this will entail, as well as concerns about pollution and depletion of surface and groundwater resources. In this note, we focus on one particular factor—climate change—and how it may contribute to future stress on water resources. We strive to lay out the basics of climate change as well as of the hydrological cycle, and we point to some of the intricate ways in which both phenomena are connected. This note does not contain blanket policy recommendations as to how to fight global warming beyond the general statement that the rational response to the risk and uncertainty of higher global temperatures and their associated environmental changes is to take actions that ensure against potentially adverse effects. The Water Cycle . . .