Greenhouse Gas Fluxes in Tropical and Temperate Agriculture: The need for a Full-Cost accounting of Global Warming Potentials

Agriculture's contribution to radiative forcing is principally through its historical release of carbon in soil and vegetation to the atmosphere and through its contemporary release of nitrous oxide (N_2O) and methane (CHM₄). The sequestration of soil carbon in soils now depleted in soil organic matter is a well-known strategy for mitigating the buildup of CO₂ in the atmosphere. Less well-recognized are other mitigation potentials. A full-cost accounting of the effects of agriculture on greenhouse gas emissions is necessary to quantify the relative importance of all mitigation options. Such an analysis shows nitrogen fertilizer, agricultural liming, fuel use, N_2O emissions, and CH₄ fluxes to have additional significant potential for mitigation. By evaluating all sources in terms of their global warming potential it becomes possible to directly evaluate greenhouse policy options for agriculture. A comparison of temperate and tropical systems illustrates some of these options.     

A proposal for design-based auto industry environmental regulation

As the U.S. auto industry tries to remain competitive in the face of evolving environmental rules, the new administration is presented with the opportunity to achieve environmental and economic goals through an industry-government partnership. The authors suggest a policy of total environmental quality as a starting point.     

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The State of Washington's Model Toxics Control Act cleanup standards, argues the author, provide the best available strategy for setting and achieving cleanup goals. Besides Protecting human health and the natural environnment, Washington's guidelines, which took effect March 1, 1991, incorporate enough flexibility to handle site-specific, finaical, and tehnological considerations. This column outlines the law's three approaches for defining cleanup levels for groundwater, surface water, air, industrial soils, and nonindustrial soils, comparing these methods with related methods in California, New Jersey, and New York.