According to the United Nations, water is “at the heart” of adaptation to climate change. Human-caused climate change, including the contributing factor of population growth, has resulted in less reliability in water supply resources as well as greater variability between water excesses and shortages. The result is growth in the frequency and intensity of water scarcity across the globe and escalating uncertainties concerning water supply. Over 748 million people around the world are without basic water access. That’s more than twice the population of the United States. As population growth continues--particularly in urban areas--so will instances of water supply scarcity. Almost half the world's population will be living in areas of high water stress by 2030 and water scarcity in some arid and semi-arid places will displace between 24 million and 700 million people. Climate change can significantly alter the water cycle, making predictions and planning for scarcity or water crisis events all the more challenging. As scarcity increases, attention to various sources and supplies of water, as well as more efficient water allocation and use, become essential for human survival and for economic growth. The estimated cost benefit to the U.S. of reducing agricultural water scarcity globally is $94 billion a year. Each water source--from groundwater, to sea water, to rivers, to rainfall, to reused water--includes climate change related challenges ranging from pollution and supply levels to consumer comfort and cost. Further, supply issues overlap with infrastructure and capacity limitations, technology considerations, and neglect of rural areas.
How might we provide water to those who need it and protect or enhance water supply sources?