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  Eco-literacy: Knowledge Isn't Enough

  Lamont Hempel

  No abstract available

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  Eutrophication

  James E. Cloern, Tim Krantz, and C Michael Hogan

  Eutrophication is a syndrome of [../152248/index.html ecosystem]] responses to human activities that fertilize water bodies with nitrogen (N) and phosphorus (P), often leading to changes in animal and plant populations and degradation of water and habitat quality. Nitrogen and phosphorus are essential components of structural proteins, enzymes, cell membranes, nucleic acids, and molecules that capture and utilize light and chemical energy to support life. The biologically available forms of N and P are present at low concentrations in pristine lakes, rivers, estuaries, and in vast regions of the upper ocean.

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  Evolving Concepts of Sustainability in Environmental Policy

  Lamont Hempel

  This article examines the evolution and application of sustainability concepts in environmental politics and policy, paying particular attention to the challenges of operationalizing and measuring sustainability in the highly dynamic environment of twenty-first-century politics and policy. It first surveys the concept's historical roots, and then examines the struggle to refine and apply the concept in contemporary policy analysis. It reviews the key policy initiatives that have incorporated sustainability language or contributed to its development within each branch of government. It then focuses on the pragmatic adoption of sustainability principles in policy making, culminating in a discussion of future directions and research needs.

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  Salton Sea, California

  Tim Krantz and C Michael Hogan

  The Salton Sea, California's largest lake, is located in the southeastern desert region of California. It lies within a 7851 square mile endorheic hydrologic basin that includes the Coachella and Imperial Valleys of California, and the Mexicali Valley of Mexico, with a surface elevation of 227 feet below mean sea level (msl). The shallow nature of this hypersaline lake, with a surface area of 367 square miles (951 square kilometers) and a maximum depth of 51 feet (15.5 meters), renders it very sensitive to even slight changes of inflow volume. Over 85 percent of the water entering the Salton Sea results from agricultural run-off, 1.34 million acre feet (Maf), with less than three percent of annual inflow deriving from basin precipitation. The Salton Sea is situated in the Colorado Desert in one of the most arid regions of the United States. Annual precipitation is less than 3 in. (7.6 cm), and mean monthly temperatures in July are 92°F (33.3°C), with maximum temperatures exceeding 100°F (37.7°C) on more than 110 days per annum. Potential evaporation is estimated at 5.78 feet (1.76 meters) per year.