The most commonly used water sources are rivers and lakes, which contain less than 0.01% of the world’s water! From a human perspective, the problem is that over 97% of this water is seawater, which is too salty to drink or use for irrigation. All of Earth’s water could cover the United States to a depth of 145 km. There is a very large volume of water on our planet, about 1.4 billion cubic kilometers (km3) or about 200 billion litres per person on Earth. About 70% of Earth’s surface is covered by oceans and approximately half of Earth’s surface is obscured by clouds (also made of water) at any time. The abundance of liquid water on Earth’s surface distinguishes us from other bodies in the solar system. Loss of 15% of body-water usually causes death.Įarth is truly the Water Planet. ![]() ![]() We constantly lose water by perspiration in temperate climates we should drink about 2 litres of water per day and people in hot desert climates should drink up to 9.5 litres of water per day. Our brain is about 85% water, blood and kidneys are 83% water, muscles are 76% water, and even bones are 22% water. Human babies are approximately 75% water and adults are 60% water. Water is the most essential compound for all living things. Plants breakdown water and use it to create oxygen during the process of photosynthesis. Water also is essential for our oxygen and food supply. Humans can live only a few minutes without oxygen, less than a week without water, and about a month without food. Water, air, and food are the most important natural resources to people. The Pacific Institute, based in Oakland, Calif., currently has three main programs of research: water, community strategies for sustainability and justice, and globalization.7.1 Water Cycle and Fresh Water Supply Introduction He is the author of numerous publications and is working on a book about bottled water. He received a BS from Yale University and an MS and PhD from the University of California, Berkeley. Gleick was elected to the National Academy of Sciences, Washington, D.C., in 2006. Because of his interests and commitment to environmental protection, the fund is used to promote an environmental ethic among business school students, alumni, and the community. The Conradin von Gugelberg Memorial Fund was established by members of the Stanford MBA Class of 1987 to honor the memory of their classmate who died shortly after graduation. “We can do it now if we don’t we’re in for much pain and suffering.” “Truly sustainable water management requires efficiencies, smart economics, improved technology, and better governance,” he said. The good news is that we can do everything we need and use far less water. And he called for proper pricing mechanisms and markets to limit cheap water. Maintaining the infrastructure we already have is important, as well as growing crops that take less water. Gleick called for looking to other kinds of water supply, such as treated wastewater, desalination, or rainwater harvesting. It’s unlikely more dams or huge infrastructure projects will be built, so what’s the alternative? ![]() Politicians and engineers have grappled for years with solutions to California’s water shortages. “Where we have nonrenewable resources, we are increasingly hitting peak ecological limits.” We’ve reached that point in California, Gleick said. After this point, taking more water for human use causes ecological disruptions far worse than the value it adds for us. At a certain point - the peak - the two forces intersect, and the value of ecological services provided by water is equivalent to the value of human services provided by water. But as we take water from the watershed, the ecological value the water was providing for plants and animals declines. It goes like this: The more uses humans have for water, the more valuable it becomes. “In many places we are past peak ecological value.”Ĭalculating the ecological value of water is central as we shift to a new way of thinking about water, he said. “As we take more and more water we reach a point where if we use one more unit it causes more harm than provides benefits,” Gleick said. Agriculture has so depleted those nonrenewable aquifers that half of the supply is used up. In some places in the West, such as the groundwater aquifers in California’s Central Valley, we have reached a peak in water production. “As our population grows, the competition for water for grows,” said Gleick, a MacArthur fellow and recognized expert on water resources, as he outlined the water supply challenges in the western United States. 9 during the 2010 Conradin von Gugelberg Memorial Lecture on the Environment. ![]() That is the message Peter Gleick, president of the Pacific Institute, gave to Stanford Graduate School of Business students Feb. But we are depleting some important water sources necessary for growing food and sustaining fisheries.
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