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.

关键词： CLIMATIC changes   AGRICULTURAL productivity   ECONOMETRIC models   AGRICULTURE -- Research   HIGH temperatures  

摘要： This paper investigates the impacts of climate change on US returns to research investments on agricultural productivity. We examine this using a historical data set in a panel time-series econometric model of state agricultural productivity. The fitted model allows derivation of the rate of return to research investments and the effects of climate change thereon. We find climate change is altering the rate of return to public agricultural research in a spatially heterogeneous manner. Increases in precipitation raise returns to research, while the impact of higher temperatures varies by region, are negative in Southern areas, particularly the Southern Plains, and positive in northern areas. We simulate the impact of projected climate change and find cases where agricultural productivity is reduced, for example in the Southern Plains. Finally, we consider the amount of research investment that is needed to adapt to overcome the impacts of climate change on agricultural productivity. Under the 2100 scenario, a 7-17 % increase in total US research investment is needed to adapt, but effects by region differ greatly-some requiring little changes and the Southern Plain requiring an increase as high as 57 %.

关键词： industrial research   cereal-growing   Climate   climate change   Agriculture Production   Ecological Impacts of Climate Change   Ethiopia   Rainfall  

摘要： Nearly all of Ethiopia's agriculture is dependent on rainfall, particularly the amount and seasonal occurrence. Future climate change predictions agree that changes in rainfall, temperature, and seasonality will impact Ethiopia with dramatic consequences. When, where, and how these changes will transpire has not been adequately addressed. The objective of our study was to model how projected climate change scenarios will spatially and temporally impact cereal production, a dietary staple for millions of Ethiopians. We used Maxent software fit with crop data collected from household surveys and bioclimatic variables from the WorldClim database to develop spatially explicit models of crop production in Ethiopia. Our results were extrapolated to three climate change projections (i.e., Canadian Centre for Climate Modeling and Analysis, Hadley Centre Coupled Model v3, and Commonwealth Scientific and Industrial Research Organization), each having two emission scenarios. Model evaluations indicated that our results had strong predictability for all four cereal crops with area under the curve values of 0.79, 0.81, 0.79, and 0.83 for teff, maize, sorghum, and barley, respectively. As expected, bioclimatic variables related to rainfall were the greatest predictors for all four cereal crops. All models showed similar decreasing spatial trends in cereal production. In addition, there were geographic shifts in land suitability which need to be accounted for when assessing overall vulnerability to climate change. The ability to adapt to climate change will be critical for Ethiopia's agricultural system and food security. Spatially explicit models will be vital for developing early warning systems, adaptive strategies, and policy to minimize the negative impacts of climate change on food production.

关键词： CLIMATIC changes   ACCLIMATIZATION   AGRICULTURE   ADAPTATION (Biology)  

摘要： Climate change is putting Colombian agriculture under significant stress and, if no adaptation is made, the latter will be severely impacted during the next decades. Ramirez-Villegas et al. (2012) set out a government-led, top-down, techno-scientific proposal for a way forward by which Colombian agriculture could adapt to climate change. However, this proposal largely overlooks the root causes of vulnerability of Colombian agriculture, and of smallholders in particular. I discuss some of the hidden assumptions underpinning this proposal and of the arguments employed by Ramirez-Villegas et al., based on existing literature on Colombian agriculture and the wider scientific debate on adaptation to climate change. While technical measures may play an important role in the adaptation of Colombian agriculture to climate change, I question whether these actions alone truly represent priority issues, especially for smallholders. I suggest that by i) looking at vulnerability before adaptation, ii) contextualising climate change as one of multiple exposures, and iii) truly putting smallholders at the centre of adaptation, i.e. to learn about and with them, different and perhaps more urgent priorities for action can be identified. Ultimately, I argue that what is at stake is not only a list of adaptation measures but, more importantly, the scientific approach from which priorities for action are identified. In this respect, I propose that transformative rather than technical fix adaptation represents a better approach for Colombian agriculture and smallholders in particular, in the face of climate change.

关键词： 皖东南地区   气候   农业  

摘要： 为了应对气候变化对宣城市农业造成的影响,采用宣城市2012年气象资料、农业灾情资料,统计分析气候变化对宣城市农业的不利影响。结果表明,全市平均年降水量与常年相比偏多7.6%,除宣城为负距平以外,其余各县(市)为正距平。年内除4、6、7月和10月降水量较常年偏少外,其余月份降水量均偏多。入梅、出梅期偏迟,全市平均梅雨量较常年偏少。全市年平均气温正常略偏高,高温日数比常年偏多8天。主要气候事件是2月22日—3月23日全市出现长时间低温阴雨天气,6月27—28日部分地区出现的强降雨和第11号台风"海葵"对宣城市的影响。气象灾害对农业的不利影响大,但粮油的单产、总产比2011年略有增产,气候上属正常偏好年景。

关键词： AGRICULTURAL productivity   CROPS & climate   RESEARCH & development   WEATHER forecasting   FARMERS   CLIMATIC changes   TRAINING of  

摘要： The agricultural sector is highly vulnerable to future climate changes and climate variability, including increases in the incidence of extreme climate events. Changes in temperature and precipitation will result in changes in land and water regimes that will subsequently affect agricultural productivity. Given the gradual change of climate in the past, historically, farmers have adapted in an autonomous manner. However, with large and discrete climate change anticipated by the end of this century, planned and transformational changes will be needed. In light of these, the focus of this review is on farm-level and farmers responses to the challenges of climate change both spatially and over time. In this review of adapting agriculture to climate change, the nature, extent, and causes of climate change are analyzed and assessed. These provide the context for adapting agriculture to climate change. The review identifies the binding constraints to adaptation at the farm level. Four major priority areas are identified to relax these constraints, where new initiatives would be required, i.e., information generation and dissemination to enhance farm-level awareness, research and development (R&D) in agricultural technology, policy formulation that facilitates appropriate adaptation at the farm level, and strengthening partnerships among the relevant stakeholders. Forging partnerships among R&D providers, policy makers, extension agencies, and farmers would be at the heart of transformational adaptation to climate change at the farm level. In effecting this transformational change, sustained efforts would be needed for the attendant requirements of climate and weather forecasting and innovation, farmer's training, and further research to improve the quality of information, invention, and application in agriculture. The investment required for these would be highly significant. The review suggests a sequenced approach through grouping research initiatives into short-term, m

关键词： Cotton (Gossypium hirsutum L.)   Climate change   North Cameroon   Cropping systems   Crop modeling  

摘要： This article predicts an unexpected positive effect of climate change on cotton production in Cameroon. Global warming could threaten cotton production in Africa due to increasing temperature and CO2, and rainfall uncertainties. This situation is worsened by the fact that most African farmers grow cotton as their cash crop and have few or no possible alternatives. Assessing the impact of climate change on cotton production is therefore critical. Here, we used CROPGRO, a process-based crop model that can simulate the main features of cotton growth and management. We applied this model to two regions in North Cameroon and a set of six regional climate projections combining general climate models and regional climate models from the ENSEMBLES project. The model was calibrated and validated with a data set of observations made in farmer fields from 2001 to 2005 and at an experimental station in 2010. Our results show unexpectedly that climate change from 2005 to 2050 in North Cameroon will have a positive effect on cotton yields with an increase of 1.3 kg ha(-1) year(-1) in yield, especially if conservation agriculture systems are adopted. The predicted increase of 0.05 A degrees C year(-1) in temperature will shorten crop cycles by 0.1 day year(-1) with no negative effect on yields. Moreover, the fertilizing effect of CO2 enrichment will increase yields by approximately 30 kg ha(-1). The rainfall pattern is likely to change, but the six regional models used to generate future weather patterns did not predict a decrease in rainfall. One model even forecast an increase in rainfall amounts. According to our findings, climate changes in North Cameroon can be anticipated by tailoring alternative cropping systems and adaptation techniques to cope with climate change.

关键词： Crop water requirement   Agricultural planning development   Water allocation   Climate change  

摘要： Societies are facing major challenges in allocating water resources to growing water demands due to population growth and industrial and agricultural developments. With increasing water scarcity, the need to increase agricultural water productivity is receiving significant attention in developing countries. Among alternative options for meeting increasing water demand, improving productivity has received considerable attention. Therefore, planning of water systems to face future development conditions needs further studies on land, water use, and resources as well as consideration of objectives to maximize crop production to achieve the maximum net return. Because climate change is likely to have impact on the hydrological cycle and consequently on the available water resources and agricultural water demand, there are concerns about the effects of climate change on agricultural productivity. Considering climate change impacts, in order to optimize agricultural productivity, practical frameworks and models based on comprehensive researches and studies need to be developed. The goal of this study is to develop an agricultural planning model in order to optimize the cultivated area, crop pattern, and irrigation efficiency based on the estimations of crop water requirements, water availability, and water allocation to irrigation. For this purpose, the Aharchay watershed located in the northwestern part of Iran is selected as the case study. For crop water requirement estimation, the output of an atmosphere-ocean general circulation model statistically downscaled and used as inputs to a computer model. Then water supply resources are assessed using a water allocation planning tool. The results of this study show the significance of integration and using different tools and methods in assessing and allocating water resource in regions with limited or scarce water resources. (C) 2013 American Society of Civil Engineers.

关键词： 气候变化   适应性措施   小麦   产量  

摘要： 以江苏省新沂市农户为对象，在气候变化背景下，调查全球环境基金（GEF）赠款在2008--2011年期间为优质小麦生产的目标而推行的各种适应性农艺措施的实施效果。分析表明，农民对GEF的认知程度、秸秆还田配施氮肥技术实施比例、小麦节水灌溉措施、肥料深施的比例等方面，项目区均高于非项目区，差异显著；各种病虫害发生程度项目区均小于非项目区。项目区有机肥使用比非项目区高9．5百分点，增产比例高11．3百分点；9000ks／hm2小麦高产的农户在项目区极显著多于非项目区，而4500kg／hm2低产的农户项目区比非项目区低5．8百分点。2008—2011年新沂市冬天低温来临早且持续时间长，项目区86％农户在10月20日前播种小麦且70．2％农户播种量为150—225ks／hm2；而非项目区播种普遍较迟，33．4％农户在10月21-30日播种且50％农户播种量达300—375kg／hm2。结果表明，新沂市项目区农民大多知道根据气候变化及时调整农技措施，与非项目区差异显著。本研究为未来适应气候变化的农业措施推广与开发提供参考依据。