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71.
Many developing countries, especially in Africa, contribute only very small amounts to the world total of greenhouse gas emissions. For them, the reduction of such emissions is not a priority, and the more important issue is to find ways to reduce their vulnerability to the projected climate change which is being imposed upon them largely as a result of emissions from developed countries. This priority does not accord with the ultimate objective of the United Nations Framework Convention on Climate Change, which is to achieve stabilization of greenhouse gas emissions. This paper reports upon studies in Uganda designed to help in the development of a national adaptation strategy, and addresses the need to reconcile such a strategy with the global priority accorded to mitigation and with national economic development priorities. Some features of a national climate change adaptation strategy are identified and questions are raised about the need for an international regime to facilitate and support adaptation.  相似文献   
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ABSTRACT: Many natural and anthropogenic factors contribute to the stability or erodibility of stream channels. Although a stream rating procedure used by more than 60 percent of the U.S. National Forests provides an estimate of overall stability, it does not identify the cause of instability or indicate corrective management. To better sort natural from livestock influences, stream stability rating indicator variables were related to stream types and levels of ungulate bank damage in a large data base for streams in northern Nevada. Stability and the range in stability varied naturally with stream type. Ungulate bank damage had different effects on different stream types and on different parts of their cross-sections. Vegetation is more important for stability on certain stream types than on other types. Streams with noncohesive sand and gravel banks are most sensitive to livestock grazing. Range managers should consider the stream type when setting local standards, writing management objectives, or determining riparian grazing strategies.  相似文献   
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Regional Environmental Change - The Brazilian Northeastern semi-arid region’s history has been characterized by drought, water scarcity, and poor living conditions. For the last...  相似文献   
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The electric power grid is a critical societal resource connecting multiple infrastructural domains such as agriculture, transportation, and manufacturing. The electrical grid as an infrastructure is shaped by human activity and public policy in terms of demand and supply requirements. Further, the grid is subject to changes and stresses due to diverse factors including solar weather, climate, hydrology, and ecology. The emerging interconnected and complex network dependencies make such interactions increasingly dynamic, posing novel risks, and presenting new challenges to manage the coupled human–natural system. This paper provides a survey of models and methods that seek to explore the significant interconnected impact of the electric power grid and interdependent domains. We also provide relevant critical risk indicators (CRIs) across diverse domains that may be used to assess risks to electric grid reliability, including climate, ecology, hydrology, finance, space weather, and agriculture. We discuss the convergence of indicators from individual domains to explore possible systemic risk, i.e., holistic risk arising from cross-domain interconnections. Further, we propose a compositional approach to risk assessment that incorporates diverse domain expertise and information, data science, and computer science to identify domain-specific CRIs and their union in systemic risk indicators. Our study provides an important first step towards data-driven analysis and predictive modeling of risks in interconnected human–natural systems.

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The divergent roles of education in predicting environmental support among liberals, conservatives, and moderates in the United States are explained by integrating ideological-consistency and information-deficit models. Increased political polarization among elites has led to divergent environmental positions advocated by liberal and conservative political and media leaders; it was predicted that education would increase public attention to these elite cues and, consistent with the ideological-consistency model, increased education would lead to attitudes in line with consensual positions endorsed by party elites. Across two nationally representative data sets, higher levels of education were associated with stronger environmental support among liberals and weaker environmental support among conservatives. Moderates were predicted to have fewer elite cues on which to base their attitudes; consistent with the information-deficit model, higher levels of education among moderates were associated with strengthened environmental support. A moderated-mediation model supported the differential application of these two theories.  相似文献   
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ABSTRACT: The Rio Grande Valley National Water-Quality Assessment study unit encompasses about 45,700 square miles in Colorado, New Mexico, and Texas upstream from the gaging station Rio Grande at El Paso, Texas, and includes surface-water closed basins east of the Continental Divide in New Mexico, and the San Luis Closed Basin in Colorado. The mean annual precipitation ranges from less than 6 to more than 50 inches; potential evapo-transpiration ranges from less than 35 to more than 80 inches per year. Land use is mainly rangeland, forest land, and cropland. Total irrigated acreage in 1990 was about 914,000 acres and water use was about 3,410,000 acre-feet. Two structural settings are found in the study unit: alluvial basins and bedrock basins. The alluvial basins can have through-flowing surface water or be closed basins. The discussion of streamflow and water quality for the surface-water system is based on four river reaches for the 750 miles of the main stem. The quality of the ground water is affected by both natural process and human activities and by nonpoint and point sources. Nonpoint sources for surface water include agriculture, hydromodification, and mining operations; point sources are mainly discharge from wastewater treatment plants. Nonpoint sources for ground water include agriculture and septic tanks and cesspools; point sources include leaking underground storage tanks, unlined or manure-lined holding ponds used for disposal of dairy wastes, landfills, and mining operations.  相似文献   
80.
Summary Nonmigratory populations of Whitecrowned Sparrows in coastal California exhibit dialects in territorial male songs that are stable in space and time. By field playback experiments, we tested a prediction from the hypothesis that male aggressive interactions prohibit mixing of song dialects. Playback of the home dialect Clear song to territorial males singing the Clear dialect resulted in less response than that given to playback of the neighboring Buzzy dialect. Response to both Buzzy and Clear dialect songs by target Clear males, however, was greater than that given to the Bodega dialect recorded 55 km away (Figs. 2 and 3). We conclude that these results are consistent with the hypothesis that male-male aggressive interactions play an important role in reducing dialect mixing.  相似文献   
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