Page - 8 - in Water, Energy, and Environment - A Primer

appetite formeatandothergoods thataremorewater-intensive to produce. Indevelopingcountries,where thevastmajorityofboth population growth and rising incomes can be found, a 50% increase in water withdrawals is expected by 2025, while developed countries will increase by 18%. As a result, as UN-Water highlights, water use continues to expand at more than twice the rate of populationgrowth (7).’ An additional consideration, with major implications for global tensions, is that freshwater resources are not distributed uniformly around the globe, either in time or geography. Some locations have large resources of freshwater, and some have little or none. Even where resources exist, water scarcity can exist during specific times of the year – for example, when snow melt at one time cannot be captured for use at another time. It does not then come as a surprise that the struggle to control water resources has shaped human economic and political history. Globally, the 215 international rivers and 300 groundwater basins that are shared by two or more countries have often generated tensions. For example, in the volatile Middle East, water is a source of conflict not only between the Israelis and Palestinians, but also between Egypt and Sudan, and among Turkey, Syria and Iraq. Such tensions also exist between several states in theUS, and elsewhere aswell. It is also important to recognize that theprecipitation (rainfall) patterns that bring much of the world’s freshwater will change as a result of global warming and climate change, often with adverse consequences. A more comprehensive discussion of this topic can be found in Chapters 4 and 10. Over-pumping anddepletion of underground aquifers, aswell as contamination of freshwater sources, are also serious concerns. It is estimated that withdrawals by farmers in India, China, the US, and elsewhere already exceed natural replenishment by 4%, and that gap is growing. Industrial, municipal, and agricultural runoff are contaminating existing freshwater sources, requiring water treatment before reuse. Water,Energy, andEnvironment–APrimer8