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Dennis Leaf 《人类与生态风险评估》2001,7(5):1211-1226
There are several air pollution issues that concern the international community at the regional and global level, including acid deposition, heavy metals, persistent organic pollutants, stratospheric ozone depletion, and climate change. Governments at the regional and global levels have entered into various agreements in an effort to deal with these problems. This paper deals with two major global atmospheric change issues: stratospheric ozone depletion and climate change. The focus is on the policy responses of the United States to these global issues. The United States has signed and ratified international agreements to deal with both problems. The Vienna Convention and the Montreal Protocol on Substances that Deplete the Ozone Layer have led to an effort in both developed and developing countries to phase out ozone depleting substances. The United Nations Framework Convention on Climate Change (UNFCCC) has been signed and ratified by over 180 countries. The UNFCC contained no binding targets and timetables for emissions reductions. The Kyoto Protocol (1997) to the UNFCCC did contain targets and timetables for reductions of greenhouse gases on the part of developed countries. The United States has signed but not ratified the Kyoto Protocol. The United States has experienced some movement to reduce greenhouse gas emissions on the part of various levels of government as well as the private sector. The policy process is constantly informed by scientific research. In the case of stratospheric ozone depletion and climate change, much of this work is carried out under the auspices of international scientific panels. From a policy perspective, there is a great deal of interest in the use of indicators for assessing the scope and magnitude of these problems, both for fashioning policy responses as well as assessing the impact of adopted programs to reduce ozone depleting substances, and potentially, greenhouse gases. This paper will discuss some of the indicators used for stratospheric ozone depletion and climate change. 相似文献
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Perfect counterimages were created when Europeans and American Indians met for the first time in the late 15th century. Unfortunately, historic documents have preserved only one-half of the image. How did the survivors of epidemics, enslavements, and brutalities react to the disruptions in their lives brought about by trespassers from another continent? In this article I examine the historic and archeological evidence for migration into Florida as one of the strategies employed by the displaced people from the Caribbean Islands. The existing records are enhanced by archeological investigations at wet sites, such as Hontoon Island, where surviving biological materials offer information about environment, human skeletons, diet, technologies, and artistic creations in bone and wood that usually perish on dryland sites. At Hoonton Island, water-saturated strata that were not trampled or compressed after deposition revealed that the midden was composed of a prehistoric and an early historic component. The presence of a number of European artifacts led to the conclusion that the extensive changes documented in six of the seven categories of recovered material items resulted either from direct or indirect contact with Europeans or with Indians fleeing the Europeans. New designs on bone objects occur in the early historic period. I attempt to trace the source of one of these designs in an effort to determine the direction of flow for the changes. The use of trait lists to establish relationships is not popular but, in this instance, the investigation of a specific design is enlightening. 相似文献
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