Bottlemania - Elizabeth Royte [79]
Meanwhile, across the nation and around the globe, rising temperatures, population growth, drought, and increased pollution and development continue to strain water resources—its distribution, availability, and quality. The coming scarcity will hurt the growth of jobs, housing, and businesses. Water experts predict shortages will pit communities and states against each other, states’ rights against national interests, the rich against the poor, cities against villages, corporations against individuals, and humans against other creatures that compete with us for water—such as delta smelt in the Sacramento–San Joaquin River delta, or mussels and sturgeon in Georgia, where water allocations that favor endangered species have angered upstream consumers. Scarcity will force us to change our minds—and, it is to be hoped, our behavior—about everything from landscaping to how often we eat meat.
Already, larger bodies of water across the United States are changing in ways that worry scientists. Lakes Superior, Huron, and Michigan, which contain nearly 20 percent of the world’s fresh surface water, have been in steep decline since the late 1990s, with water levels lower than normal because of reduced snowmelt and increased evaporation; the lakes are also warmer because of higher ambient temperatures. (Nestlé pumps 114 billion gallons a year from groundwater that feeds Lake Michigan, and Coke and Pepsi recently signed contracts with Detroit to bottle and ship Great Lakes water.)
In Lake Tahoe, increased sediment and pollution—a result of development—fuel the growth of algae, which absorb light and increase the water’s temperature. In the 1960s, a Secchi disk—the same black-and-white circle Miles Waite threw overboard on Lovewell Pond—was visible to one hundred and two feet; in 2006, the lake’s visibility was reduced to sixty-seven feet. In the Southeast, the worst drought in a hundred years has lowered reservoir levels in Alabama to the point where pumps, sucking mud, have shut down. Before the Army Corps of Engineers slashed water releases for endangered species, Atlanta, toward the end of 2007, had enough readily available drinking water to last just a few months, and Georgia is feuding with Alabama and Florida over allocations. Workers at one dried-up Southeastern reservoir now mow it. With its creek and spring gone dry, the tiny town of Orme, Tennessee, imports water in a truck. Residents race home to wash clothes, cook meals, and take showers during the three daily hours the spigot runs.
Global warming will affect the quality of our water as well as its quantity. In warmer temperatures, more microbes flourish in surface water; if they move into pipes, they could feed biofilms, which include pathogens, in the distribution system. Climatologists agree that global warming will make the earth, on average, wetter. But more rain and snow will fall closer to the poles, and precipitation will fall during sporadic, intense storms, rather than smaller, more frequent ones. A warmer climate will bring more frequent floods, which will increase the flow of sediment and polluted runoff into our water supplies. Floods will damage pipes that move good water in and bad water out. In drier areas, perversely, we’ll see more droughts. Not only will there be less water for home consumption, industry, and agriculture, there will be less water to dilute pollutants.
A report released by the Union of Concerned Scientists in