关键词： CLIMATIC changes   AGRICULTURE   PREDICTION models   STREAMFLOW   FERTILIZATION of plants   IRRIGATION farming  

摘要： Based on predicted changes in the magnitude and distribution of global precipitation, temperature and river flow under the IPCC SRES A1B and A2 scenarios, this study assesses the potential impacts of climate change and CO2 fertilization on global agriculture. The analysis uses the new version of the GTAP-W model, which distinguishes between rainfed and irrigated agriculture and implements water as an explicit factor of production for irrigated agriculture. Future climate change is likely to modify regional water endowments and soil moisture. As a consequence, the distribution of harvested land will change, modifying production and international trade patterns. The results suggest that a partial analysis of the main factors through which climate change will affect agricultural productivity provide a false appreciation of the nature of changes likely to occur. Our results show that global food production, welfare and GDP fall in the two time periods and SRES scenarios. Higher food prices are expected. No matter which SRES scenario is preferred, we find that the expected losses in welfare are significant. These losses are slightly larger under the SRES A2 scenario for the 2020s and under the SRES A1B scenario for the 2050s. The results show that national welfare is influenced both by regional climate change and climate-induced changes in competitiveness.

关键词： headwaters   aminoethylisothiouronium   Catchment area   nitrogen cycle   Wetlands   climate change   atmospheric CO2  

摘要： Climate change and increased atmospheric CO2 concentration can impact hydrological and nitrogen cycling at the catchment scale. The objective of this study is to assess these impacts in an intensive agricultural headwater catchment in western France. A calibrated and validated agro-hydrological model was driven by output of the climate model ARPEGE under the A1B emission scenario over 30-year simulation periods. Our study indicated that with climate warming and increased atmospheric CO2, the main trends in water balance were a decrease in annual actual evapotranspiration (AET), a decrease in annual discharge and wetland extent, and a decrease in spring and summer of groundwater recharge and soil-water content. Not considering the effects of increased atmospheric CO2 in the agro-hydrological model led to overestimating discharge decrease and underestimating AET decrease and wetland extent. Climate change could influence N cycling by increasing soil N mineralisation, increasing soil denitrification in wetlands and upstream areas, and decreasing NO3-N load to streams. Since wetlands appear to be sensitive to climate change, improving modelling to better predict their responses is an important issue, especially to help plan sustainable management of these vulnerable areas.

关键词： SWA   climate change   agricultural pollution   streamflow   sediment   nitrate  

摘要： Bracketing the uncertainty of streamflow and agricultural runoff under climate change is critical for proper future water resource management in agricultural watersheds. This study used the Soil and Water Assessment Tool (SWAT) in conjunction with a Latin hypercube climate change sampling algorithm to construct a 95% confidence interval (95CI) around streamflow, sediment load, and nitrate load predictions under changes in climate for the Sacramento and San Joaquin River watersheds in California's Central Valley. The Latin hypercube algorithm sampled 2000 combinations of precipitation and temperature changes based on Intergovernmental Panel on Climate Change projections from multiple General Circulation Models. Average monthly percent changes of the upper and lower 95CI limits compared to the present-day simulation and a statistic termed the "r-factor" (average width of the 95CI band divided by the standard deviation of the 95CI bandwidth) were used to assess watershed sensitivities. 95CI results indicate that streamflow and sediment runoff in the Sacramento River watershed are more likely to decrease under climate change compared to present-day conditions, whereas the increase and decrease for nitrate runoff were found to be equal. For the San Joaquin River watershed, streamflow slightly decreased under climate change, whereas sediment and nitrate runoff increased compared to present-day climate. Comparisons of watershed sensitivities indicate that the San Joaquin River watershed is more sensitive to climate changes than the Sacramento River watershed, which is largely caused by the high density of agricultural land. Copyright (C) 2012 John Wiley & Sons, Ltd.

关键词： 低碳农业   气候变化   温室气体   实现途径  

摘要： 全球气候变化,尤其是全球气候变暖已成为不争的事实。人类社会生产生活引起的温室气体排放是造成全球气候变化的主要原因。农业温室气体排放占全球温室气体排放总量的14%。发展低碳农业已成为当务之急。文章在探讨中国发展低碳农业意义的基础上,提出通过立法、利用财税和市场手段、增加低碳农业科技投入、加大宣传力度,转变农民传统生产观念等途径实现中国低碳农业。

关键词： 气候变化   农业   适应   减缓   研究进展  

摘要： 应对频发的极端天气气候灾害,是全球和中国农业可持续发展研究中的重要议题。中国农业在应对气候变化中采取了积极政策和科学措施,在保障粮食九连增和国民经济持续高速发展方面做出了重要贡献。本文通过对气候变化在中国农业影响事实进行了具体分析,对"十一五"期间国家科技支撑计划农业领域等有关项目在适应和减缓气候变化方面的主要研究进展和成果进行了总结和分析。结果表明,气候变化对农业发展带来机遇与挑战并存,中国研制和推行的减缓和适应气候变化关键技术发挥了不同程度的作用,并相继建立了气候变化对中国农业影响评估模型和方法,指明了今后中国农业应对气候变化科技发展的方向。

关键词： 气候变化   水稻产量   CGE模型   区域经济  

摘要： 本文通过借鉴以往的关于未来50年气候变化情景下对玉米产量增产和减产的潜力的研究结论,利用中国农业多区域CGE模型来模拟玉米在分别增产5%、10%、15%和分别减产5%、10%、15%的情况下对区域宏观经济、区域农业部门、工业部门和服务业部门的影响。结果表明:气候变化导致我国玉米增产的政策模拟方案中,气候变化对我国粮食安全的主要影响对整个宏观经济以正影响为主,气候变化导致我国玉米减产的政策模拟方案中,气候变化对我国粮食安全的主要影响对整个宏观经济以负影响为主;气候变化导致的粮食产量的变化除了对粮食主产区的影响较大外,对西部地区的新疆、西藏影响也较大;玉米减产与玉米增产模拟的结果虽然有很大程度的对应性,但从影响程度来看,玉米增产的影响要大于玉米减产对宏观经济及农业、工业和服务业部门的影响。

关键词： 水肥一体化   干旱气候   一体化技术   农业发展   管道灌溉系统   节水农业技术   高效利用   干旱事件  

摘要： 水肥一体化是利用管道灌溉系统，将肥料溶解在水中，同时进行灌溉与施肥，适时、适量地满足农作物对水分和养分的需求，实现水肥同步管理和高效利用的节水农业技术。我国已进入气候剧烈变化阶段，未来大部分地区干旱将逐步加剧，极端干旱事件将大幅度增加，跨区域、跨季节、跨年度旱灾发生将不可避免。

关键词： Climate adaptation   Participatory process   Stakeholder network   Experiential learning  

摘要： Within the context of a changing climate, scientists are called to engage directly with agricultural stakeholders for the coproduction of relevant information that will support decision making and adaptation. However, values, beliefs, identities, goals, and social networks shape perceptions and actions about climate change. Engagement processes that ignore the socio-cultural context within which stakeholders are embedded may fail to guide adaptive responses. To facilitate dialog around these issues, the Southeast Climate Consortium and the Florida Climate Institute formed a climate learning network consisting of row crop farmers, agricultural extension specialists, researchers, and climate scientists working in the Southeast US. Regional in scope, the learning network engages researchers and practitioners from Alabama, Georgia, and Florida as partners in adaptation science. This paper describes the ongoing interactions, dialog, and experiential learning among the network's diverse participants. We illustrate how participatory tools have been used in a series of workshops to create interactive spaces for knowledge coproduction. For example, historical timelines, climate scenarios, and technology exchanges stimulated discussions about climate-related risk management. We present findings from the workshops related to participants' perspectives on climate change and adaptation. Finally, we discuss lessons learned that may be applicable to other groups involved in climate education, communication, and stakeholder engagement. We suggest that the thoughtful design of stakeholder engagement processes can become a powerful social tool for improving decision support and strengthening adaptive capacity within rural communities.

关键词： Climate change   mitigation   agriculture   H.R. 2454   carbon sequestration   afforestation  

摘要： This study examines how the proposed American Clean Energy and Security Act (H.R. 2454) would affect U.S. agriculture with special reference to water resources. The bill's cap and trade provisions for greenhouse gases would significantly raise fertilizer, irrigation pumping, and other energy-related costs. By 2030, it would reduce U.S. irrigation water use by >11 percent and fertilizer use by >18 percent with positive implications for water conservation and quality. Carbon offset provisions create financial incentives for farmers to sequester carbon by planting trees on cropland, reducing agricultural production and raising prices. Because sequestration potential differs by region, most of the estimated 51 million acres of converted cropland would be in the Corn Belt and Mississippi Delta. Afforestation would reduce Delta water use further, but increase water use in other regions compared to cap and trade alone. Compared to a no-policy baseline, irrigation water use declines 10 percent nationally, but increases in the Southern Plains. H.R. 2454 may have significant water conservation effects in some regions, but increase competition for water in others. By reducing fertilizer use and dramatically altering land use patterns in parts of the Mississippi Basin, it may also provide unexpected water quality benefits. Unintended water use and quality consequences of climate policies merit further research.

关键词： CLIMATIC changes   AGRICULTURAL education   AGRICULTURAL geography  

摘要： The projected impact of climate change on agro-ecological systems is considered widespread and significant, particularly across the global tropics. As in many other countries, adaptation to climate change is likely to be an important challenge for Colombian agricultural systems. In a recent study, a national-level assessment of the likely future impacts of climate change on agriculture was performed (Ramirez-Villegas et al. Clim Chang 115:611-628, 2012, RV2012). The study diagnosed key challenges directly affecting major crops and regions within the Colombian agricultural system and suggested a number of actions thought to facilitate adaptation, while refraining from proposing specific strategies at local scales. Further insights on the study were published by Feola (2013) (F2013), who stressed the need for transformative adaptation processes to reduce vulnerability particularly of resource-limited farmers, and the benefits of a predominantly stakeholder-led approach to adaptation. We clarify that the recommendations outlined in RV2012 were not intended as a recipe for multi-scale adaptation, but rather a set of actions that are required to diagnose and develop adaptation actions particularly at governmental levels in coordination with national and international adaptation initiatives. Such adaptation actions ought to be, ideally, a product of inclusive sub-sectorial assessments, which can take different forms. We argue that Colombian agriculture as a whole would benefit from a better outlining of adaptation needs across temporal scales in sub-sectorial assessments that take into account both RV2012 and F2013 orientations to adaptation. We conclude with two case studies of research on climate change impacts and adaptation developed in Colombia that serve as examples of realistic, productive sectorial and sub-national assessments.