关键词： Global warming   Groundwater resources   CO2   Deficit irrigation   Crop yield  

摘要： The present study evaluated the potential impacts of climate change of Hamadan-Bahar plain on dimensions including economical, physiological, hydrological and meteorological aspects. The results showed that climate change in the region has negative impacts on the agricultural sector by reducing the crop yield as well as groundwater balance. In the most optimistic scenario on the horizon of 2090, rainfall and groundwater levels would reduce by 14.4 and 12.3 %, respectively and the average temperature would rise by 14.7 %. Accordingly, the economic value of water would increase by 44 % and the agricultural value-added (net income) would fall by 19 %, indicating the intensification of water shortage crisis and agricultural recession. Also, the results of this study show that optimal deficit irrigation strategy in the production of water intensive crops as well as improving irrigation technologies would be potential solutions to the climate change crisis in the coming years. However, the common pool nature of groundwater resources in addition to capital inadequacy are the challenges faced when adopting these two approaches by farmers.

关键词： Climate change   crop yield   production function   large panel data models   C23   C54   D24   Q15   Q51   Q54   Q55  

摘要： We study potential impacts of future climate change on U.S. agricultural productivity using county-level yield and weather data from 1950 to 2015. To account for adaptation of production to different weather conditions, it is crucial to allow for both spatial and temporal variation in the production process mapping weather to crop yields. We present a new panel data estimation technique, called mean observation OLS (MO-OLS) that allows for spatial and temporal heterogeneity in all regression parameters (intercepts and slopes). Both forms of heterogeneity are important: We find strong evidence that production function parameters adapt to local climate, and also that sensitivity of yield to high temperature declined from 1950-89. We use our estimates to project corn yields to 2100 using 19 climate models and three greenhouse gas emission scenarios. We predict unmitigated climate change will greatly reduce yield. Our mean prediction (over climate models) is that adaptation alone can mitigate 36% of the damage, while emissions reductions consistent with the Paris targets would mitigate 76%.

关键词： Climate change   Distributional effects   Agriculture   Quantile regression   Census data   Brazil  

摘要： The economic impact of global warming likely varies across farms because of differences in climate, technology, and adaptive capacity. Therefore, aggregate estimates of the average effect of warming may be insufficient to model climate change vulnerability. In this study, I propose a quantile model for the distributional effect of climate change. I estimate inter-quantile regressions of land value on climate using agricultural census data for 464,277 commercial farms in Brazil. I find that the effects of climate change in Brazilian agriculture vary significantly by climate, land quality, and irrigation choice. A 1 degrees C of warming is more detrimental to farms in warm climates, those with high-quality land, and those using irrigation. A 10 0-mm decrease in annual precipitation is more damaging to farms in dry climates, those with low-quality land, and those using irrigation. The heterogeneity in climate change effects is particularly large within the subset of farms in the warmest or the driest climates, as the most vulnerable farms appear to be those that have reached their limits for climate adaptation. (c) 2020 Elsevier Inc. All rights reserved.

关键词： Adaptation   Agriculture   Climate change   Crop yields   Heterogeneity   Quantile regression  

摘要： Existing studies on climate change effects on crop yields mainly focus on the average climate-yield relationship that is typically assumed to be time-invariant. We apply a flexi-ble panel-data quantile regression with time-varying coefficients to examine distributional heterogeneity and temporal variation in this relationship. We find that U.S. corn and soybean yields have gradually become less sensitive to temperature and precipitation over 1948-2010, which is especially the case for upper yield quantiles. Consequently, the negative impacts of future climate change are of larger magnitudes at the lower yield quantiles. Failure to accommodate temporal changes in the climate-yield relationship leads to significantly overestimated responsiveness of crop yields to weather variation and, therefore, overestimated negative impacts of future climate change. On many occasions, the corn yield decline projections from such time-invariant specifications are about twice as large as (and sometimes triple) the predictions from our time-varying-coefficient model. (c) 2020 Elsevier Inc. All rights reserved.

摘要： Improvement of planting season and crop growth time, considering climatic and soil needs of plants, is important to increase cassava (Manihot esculenta) production in Midwestern Brazil. Thus, we sought to develop an agricultural zoning for cassava cultivation in the Midwest of Brazil in different climate change scenarios. Mean air temperature and precipitation data from localities of the Midwest of Brazil were obtained from the Brazilian National Institute of Meteorology (INMET). Clay (%) data from localities of the Midwest of Brazil were obtained from SoilGrids. Regions where the air temperature was within the range from 20 to 27 degrees C were considered climatically favorable for commercial exploitation of cassava, in addition to precipitation between 1000 and 1500 mm year(-1), and clay content was less than <= 35%. Moreover, regions with air temperature below 16 degrees C and above 38 degrees C, precipitation below 1000 mm and above 1500 mm year(-1), and clay content > 35% were considered unsuitable for cassava cultivation. Raster or matrix images, corresponding to mean annual air temperature, annual precipitation, and clay (soil), were superimposed to create cassava suitability classes, according to crop requirements. The climate change scenarios were established by changing the air temperature (degrees C) and rainfall (mm). The air temperature was increased by 1.5, 3.0, 4.5, and 6.0 degrees C as adopted by Pirttioja et al. (Clim Res 65:87-105, 2015). We changed in precipitation - 30, - 15, + 15, and 30% according to the future projections simulated by the IPCC (2014). Maps were made using geographic information systems. In the states of Mato Grosso do Sul, Mato Grosso, and Goias, mean precipitation was around 1200 to 4000 mm year(-1). Northern Mato Grosso showed the highest annual precipitation, with values above 3500 mm. A large extension of the Midwest region of Brazil is climatically and soil favorable for cassava. The Midwest is a region with high rainfall

关键词： GLOBIOM-Brazil   Land-use competition   Change in production   Soybean   Corn   Sugar cane  

摘要： Brazilian agricultural production provides a significant fraction of the food consumed globally, with the country among the top exporters of soybeans, sugar, and beef. However, current advances in Brazilian agriculture can be directly impacted by climate change and resulting biophysical effects. Here, we quantify these impacts until 2050 using GLOBIOM-Brazil, a global partial equilibrium model of the competition for land use between agriculture, forestry, and bioenergy that includes various refinements reflecting Brazil's specificities. For the first time, projections of future agricultural areas and production are based on future crop yields provided by two Global G ridded Crop Models (EPIC and LPJmL). The climate change forcing is included through changes in climatic variables projected by five Global Climate Models in two emission pathways (RCP2.6 and RCP8.5) participating in the ISIMIP initiative. This ensemble of twenty scenarios permits accessing the robustness of the results. When compared to the baseline scenario. GLOBIOM-Brazil scenarios suggest a decrease in soybeans and corn production, mainly in the Matopiba region in the Northern Cerrado, and southward displacement of agricultural production to near-subtropical and subtropical regions of the Cerrado and the Atlantic Forest biomes. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Climate change   Subsurface transport   Trace organics   Groundwater   Agricultural production  

摘要： Climate change will impact soil properties such as soil moisture, organic carbon and temperature and changes in these properties will influence the sorption, biodegradation and leaching of trace organic contaminants to groundwater. In this study, we conducted a modeling case study to evaluate atrazine and estrone transport in the subsurface under current and future climate conditions at a field site in central Nebraska. According to the modeling results, in the future, enhanced evapotranspiration and increased average air temperature may cause drier soil conditions, which consequently reduces the biodegradation of atrazine and estrone in the water phase. On the other hand, greater transpiration rates lead to greater root solute uptake which may decrease the concentration of atrazine and estrone in the soil profile. Another consequence of future climate is that the infiltration and leaching rates for both atrazine and estrone may be lower under future climate scenarios. Reduced infiltration of trace organic compounds may indicate that lower trace organic concentrations in groundwater may occur under future climate scenarios. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Climate change   Postharvest crop storage   Storage degree days   Agricultural commodities   Contiguous United States  

摘要： Changes in postharvest storage conditions due to climate change can directly affect energy usage and food supply and quality. However, no study has assessed climate change impacts on postharvest storage conditions in different climate regions over the contiguous United States (CONUS), a major agricultural producer around the world. The goal of this study is to assess the impact of climate change on cold storage conditions for the highest grossing crop for each of the nine climate regions within the CONUS. Storage degree days (SDDs) accumulate when ambient temperatures increase relative to crop storage base temperatures. Changes in SDDs and winter subperiod length were calculated for each regional crop using historical climate data and 20 downscaled global climate model projections. All regions project significant increases in SDD accumulation and decreases in winter subperiod length when compared with the historical reference period (1979-2005). Between years 2020 and 2080, Northwest and Northeast regions' apples will be impacted most by SDD accumulation with yearly increases between 261 and 1004 SDDs. Between years 2020 and 2080, Midwest regions' potatoes are projected to lose the most days of winter (24-39 days), and Southeast regions' peanuts will experience the greatest decrease in winter length (17-23%). Increases in SDD accumulation and decreases in winter length will have direct implications on future food supply and storage costs. This study is the first comprehensive analysis of climate change impacts on the storage conditions for agricultural commodities over heterogenous climate conditions at national scale, providing useful information for long-term agricultural storage planning.

关键词： Climate change   Climate adaptation   Uncertainty   Climate communication   Agriculture   Food security  

摘要： A large survey of corn farmers in twelve US midwestern states (n = 6849) was used to determine the role of multiple dimensions of uncertainty on prior experience with climate change, attitudes towards climate adaptation, and use of climate outlooks in agricultural decision-making. Epistemic uncertainty refers to a perception about the level of information about a phenomenon. Aleatoric uncertainty is a perception that a phenomenon occurs at random and no new information will reduce uncertainty while response uncertainty refers to the perception of the efficacy of an action to reduce a risk. Epistemic and response uncertainty explained a large portion of variance of farmers' attitudes towards adaptation and their willingness to use weather and climate outlook tools. Aleatoric uncertainty however did not add or added only a small portion of variance explaining farmers' attitudes climate adaptation or use of climate tools. Our results indicate that climate scientists should not treat farmers' uncertainty as a monolithic concept, but instead embrace its multidimensionality. We also suggest that reception of expert-led presentations or tools that have a lot of modeling data, which are often layered with statistical uncertainty, can negatively influence farmers' model uncertainty.

关键词： climate change   adaptation   resilience   water resources   food security   sustainability  

摘要： Agriculture remains important in driving economic transformation, sustainable livelihoods, and development in developing countries. This paper provides a comprehensive analysis and discussion of climate change impacts on water and agriculture sectors and implications for the attainment of developmental outcomes such as food security, poverty reduction, and sustainable development in Southern Africa. The review gives policy messages for coping, adapting, and building resilience of water and agricultural production systems in the face of projected changes in climate and variability. The aim is to guide the region towards the achievement of the Sustainable Development Goals. Future projections for Southern Africa indicate reduced rainfall, increased temperatures, and high variability for the greater part of the region with severe reductions on the drier and marginal western parts. These impacts have profound implications for agriculture performance and contribution to national and regional developmental goals. The region is projected to experience reductions of between 15% and 50% in agricultural productivity, a scenario that would exacerbate food insecurity in the region. The challenge is to increase productivity on current arable land through efficient and sustainable management of available water and energy, and at the same time reducing pressure on the environment. Affordability and accessibility of innovative adaptation measures on water resources remain critical and these strategies should be part of broader sustainable development efforts. Overall, efforts to enhance agricultural productivity need to emphasise investments in sustainable management and use of water and energy resources in agriculture to achieve sustainable economic growth and livelihoods.