摘要： My dissertation estimates the economic effects of anthropogenic-induced climate change on U.S. agriculture. The dissertation postulates from the outset that farmers optimally adapt to varying environmental conditions. Thus, land prices can be used to measure the highest value use of the land. Using this assumption, this paper attempts to extend previous research on this subject in three ways. The first goal is to estimate the distributional effects of climate change on U.S. agriculture. Even though many researchers agree that the U.S. agricultural sector is likely to experience a shift of regional comparative advantage in response to changing climate, few studies actually quantify the distributional effects of global warming on U.S. agriculture. The main focus of my dissertation, therefore, is not only to estimate the aggregate impacts of climate change on U.S. agriculture, but also to examine how each region of the United Stated may be affected by changing climate. Second, most researchers believe that the pattern of climate change will be uneven across the North American continent, inducing diverse effects across different regions. Instead of assuming uniform changes in climate variables (e.g., temperature and precipitation), therefore, this research takes into account the possibility of variations in climate change across the 48 contiguous United States. Third, the dissertation accounts for the temporal aspects of anthropogenic-induced climate change. Most impact studies in the past were based on arbitrary climate change scenarios or the equilibrium-doubled CO2 General Circulation Model (GCM) scenarios in projecting the effects of global warming on US agriculture. In order to capture the time-dependent responses of the climate system and their impacts on US agriculture, however, this project uses transient climate change scenarios that allow an examination of the time-path of climate change in each U.S. county. Applying the Ricardian approach proposed by Mendelso

关键词： GREENHOUSE gas mitigation   AGRICULTURE -- United States  

摘要： The Department of Energy estimated CO sub(2) emissions for the United States to equal 1562 million metric tons of carbon equivalents (MMTCE) in 2000, which is 305 MMTCE more than in 1990. With an estimated average annual emission increase of 1.5% per year, the Kyoto Protocol would require the United States to reduce CO sub(2) by about 524 MMTCE in 2008, 549 MMTCE in 2009, 578 MMTCE in 2010, 608 MMTCE in 2011, and 635 MMTCE in 2012. Agricultural and forestry (AF) activities may mitigate greenhouse gas (GHG) emissions through (i) direct emission reductions, (ii) terrestrial carbon sink expansions, and (iii) production of replacements for emission-intensive products. Uncertainty and controversy exist about AF's practical mitigation potential, 300 partly because aggregate studies have been lacking. Competitive economic potentials for agricultural and forest GHG emission mitigation strategies in the United States. All strategies were simultaneously examined. Decreasing levels of emission reductions as prices increase reflect competition among strategies.

关键词： Agriculture/economics   Animals   Carbon   Carbon Dioxide   Climate   Conservation of Natural Resources/economics   Costs and Cost Analysis   Crops, Agricultural/economics   Fertilizers   Forestry/economics   Greenhouse Effect   Models, Theoretical   Soil   Trees   United States  

摘要： The Department of Energy estimated CO_2 emissions for the United States toequal 1562 million metric tons of carbon equivalents (MMTCE) in 2000, which is 305 MMTCE more thanin 1990. With an estimated average annual emission increase of 1.5 percent per year, the KyotoProtocol would require the United States to reduce CO_2 by about 524 MMTCE in 2008, 549 MMTCE in2009, 578 MMTCE in 2010, 608 MMTCE in 2011, and 635 MMTCE in 2012. Agricultural and forestry (AF)activities may mitigate greenhouse gas (GHG) emissions through (i) direct emission reductions, (ii)terrestrial carbon sink expansions, and (iii) production of replacements for emission-intensiveproducts (1). Uncertainty and controversy exist about AF's practical mitigation potential, partlybecause aggregate studies have been lacking (1). The heterogeneity and management interdependenciesin AF make it difficult to assess aggregate economic mitigation potential. Soil properties, climateconditions, and land management history are heterogeneous, and collectively, they result in uniqueGHG emissions mitigation potential for each field. For example, U.S. carbon concentrations inmineral soil surface layers range from less than 1 percent organic carbon for sandy soils in warm,dry climates to more than 4 percent for clay soils in cold, wet climates. Peat soils contain as muchas 50 percent organic carbon. Carbon sequestration potential depends on carbon lost during previouscultivation. Highly degraded soils with low carbon-holding capacity may have greater sequestrationpotential than fairly undisturbed soils with high capacity.

关键词： 气候变化   西北地区   农业发展   温室效应  

摘要： 将我国西北地区气候变化置于全球和全国气候变化的背景下 ,揭示了西北地区近 5 0a来气候变化的主要特征。指出近 2 0a来气候变化的总趋势为变暖变干 ,并向高温干旱化方向发展 ,分析这种气候变化对未来农业生产可能产生的影响以及所应采取的战略对策。

关键词： 重庆   气候   农业气候生产力   降水量   日照  

摘要： 相关分析结果表明，重庆6市各地年（季）平均气温升高，日照时数增多，大部地区主要年（季）降水量减少均可使年（季）农业气候生产力提高，反之年（季）农业气候生产力下降，并给出了各地在40年气候振动范围内不同气候情景和90年代以来的气候变化对年（季）农业气候生产力的影响程度。

关键词： 重庆   气候   气象灾害   农业  

摘要： 阐述了重庆市农业气候的基本特征，分析了近年来的气候变化，气象灾害特点及其对农业生产的影响和危害，这对于农业趋利避害具有参考价值。

关键词： Agriculture   Climate change   Carbon dioxide   Impact analysis  

摘要： We assert that the simulation of fine-scale crop growth processes and agronomic adaptive management using coarse-scale climate change scenarios lower confidence in regional estimates of agronomic adaptive potential.

关键词： Climate change   Agriculture   Carbon dioxide   Impact analysis  

摘要： We investigated the effect of two different spatial scales of climate change scenarios on crop yields simulated by the EPIC crop model for corn, soybean, and wheat, in the central Great Plains of the United States. The effect of climate change alone was investigated in Part I. In Part II (Easterling et al., 2001) we considered the effects of CO2 fertilization effects and adaptation in addition to climate change. The scenarios were formed from five years of control and 2 x CO2 runs of a high resolution regional climate model (RegCM) and the same from an Australian coarse resolution general circulation model (GCM), which provided the initial and lateral boundary conditions for the regional model runs. We also investigated the effect of two different spatial resolutions of soil input parameters to the crop models. We found that for corn and soybean in the eastern part of the study area, significantly different mean yield changes were calculated depending on the scenario used. Changes in simulated dryland wheat yields in the western areas were very similar, regardless of the scale of the scenario. The spatial scale of soils had a strong effect on the spatial variance and pattern of yields across the study area, but less effect on the mean aggregated yields. We investigated what aspects of the differences in the scenarios were most important for explaining the different simulated yield responses. For instance, precipitation changes in June were most important for corn and soybean in the eastern CSIRO grid boxes. We establish the spatial scale of climate change scenarios as an important uncertainty for climate change impacts analysis.

关键词： 农业生产   气候变化   季节变化   抚顺  

摘要： 通过分析抚顺近 4 0a气温、降水、积温、初终霜、大于等于 1 0℃初终日及气象灾害的演变情况 ,得出气候变化的五大主要特点 。

关键词： climate change   integrated model   New Zealand agriculture  

摘要： Internationally and nationally, New Zealand has a growing requirement to assess and report on the possible effects of climate change. In association with this requirement, the science of climate change is rapidly evolving requiring a capacity for rapid reassessment of effects to take account of scientific advances. Consequently, past assessment methods, which have not been computationally efficient, nor easily repeated, are becoming outdated. To address this gap, an integrated assessment model (IAM), the CLIMPACTS system, has been developed for New Zealand. The CLIMPACTS system has been developed to provide flexibility in application, to be easily updated to take account of scientific advances, and capable of providing information in a manner that is relevant to policymakers. In order to be relevant in New Zealand, it has been necessary to account for different scales of assessment, nationally, at specific sites, and regionally. Nationally, the focus is on spatial applications (e.g., changes in areas of suitability), whereas at sites, the focus is on temporal applications (e.g., changes in risk). The regional capacity in the CLIMPACTS system has required an integration of spatial and temporal applications. This paper describes briefly the capability that has been developed at these different scales of assessment, with brief examples for each. The CLIMPACTS system has enhanced New Zealand's capability to examine environmental sensitivities to climate change, as a basis for better informed policy decisions. Importantly, it is an evolving platform that can be readily extended to other sectors and updated, for example, to account for the effects of internationally agreed greenhouse gas (GHG) emission targets. (C) 2001 Elsevier Science Ltd. All rights reserved.