Climate Change and Agriculture

Regional and Country-level Studies

Africa

Jones, Peter G., and Philip K. Thornton. 2003. "The potential impacts of climate change on maize production in Africa and Latin America in 2055," Global Environmental Change, Vol. 13, No. 1, pp. 51 - 59.
ABSTRACT: The impacts of climate change on agriculture may add significantly to the development challenges of ensuring food security and reducing poverty. We show the possible impacts on maize production in Africa and Latin America to 2055, using high-resolution methods to generate characteristic daily weather data for driving a detailed simulation model of the maize crop. Although the results indicate an overall reduction of only 10% in maize production to 2055, equivalent to losses of $2 billion per year, the aggregate results hide enormous variability: areas can be identified where maize yields may change substantially. Climate change urgently needs to be assessed at the level of the household, so that poor and vulnerable people dependent on agriculture can be appropriately targeted in research and development activities whose object is poverty alleviation.

Amissah-Arthur, Abigail. 2003. "Targeting Climate Forecasts for Agricultural Applications in Sub-Saharan Africa: Situating Farmers in User-Space," Climatic Change, Vol. 58, No. 1-2, May, pp. 73-92.
ABSTRACT: Several meteorological services in Africa now issue seasonal climate forecasts on an operational basis. However, the failure to develop a comprehensive profile of users has resulted in a considerable gap between the information that is likely to be useful to farmers and that provided and disseminated by these services. The present study develops a methodology to characterize smallholder production systems in order to identify farmer groups who may adopt and benefit from the climate forecast information in sub-Saharan Africa. Through an extensive literature review, data and information was derived from a national household survey of 1540 smallholders in 1995-1997 by the Kenya Agricultural Research Institute and spatial georeferenced data from leading world data centers. The data were analysed and synthesized using the GIS. Considerable opportunities exist for farming communities to improve their profitability using climate forecasts. Although the needs and demand for climate forecasts vary according to the production systems and market forces that determine credit, demand and input availability and, thus, the usability of forecasts depend on the characteristics of the farmers and their place in space. Based on production strategies and options available to farmers, three zones were identified grouping farmers with highly probable, probable and less probable potential of adopting climate forecasts to alter their production practices. Although a climate forecast may be useful to all farmers in the region considered, due to different options available to individual groups of farmers, however, the benefits derived from its use may not be equitable. Some of the options available to farmers in Kenya were considered in this study with a view to highlighting why some may benefit more than others. The methodology demonstrated here could be adopted for other parts of the world for: (1) selecting survey sites to determine the benefits of climate forecasts using farmers participatory rapid rural appraisals and simulation approach, and (2) target climate information where it would be most useful.

Wilkie, David, Gilda Morelli, Fiona Rotberg, and Ellen Shaw. 1999. "Wetter isn't better: global warming and food security in the Congo Basin," Global Environmental Change, Vol. 9, No. 4, December, pp. 323-328.
ABSTRACT: Over 20 million forest farmers practice slash and burn agriculture in the forests of the Congo Basin (Bahuchet and de Maret, 1995. State of Indigenous Populations Living in Rainforest Areas, European Commission DG XI Environment, Brussels). They rely on the long dry season (December-February north of the equator) to ensure that their new fields, cleared from regrowth forest, burn sufficiently well to deposit nutrients into the soil and to minimize the labor required to prepare the field for planting. Data from the Ituri forest in northeastern Democratic Republic of Congo show that the strength of the annual dry season (a) has a direct positive impact on the size of fields cleared each year by slash and burn farmers, and consequently on food production and the severity of the subsequent year's pre-harvest hunger period; and (b) is inversely related to total annual rainfall. These results suggest that the 1 mm/d increase in rainfall predicted for much of the Congo Basin by the 2050s may cause a basin wide increase in the frequency of heavy rains during the dry season, causing a reduction in the size of slash and burn farmers' fields, and potentially a substantial increase in the food insecurity of poor rural families across the region.

Feddema, Johannes J. 1999. "Future African Water Resources: Interactions between Soil Degradation and Global Warming," Climatic Change, Vol. 42, No. 3, July, pp. 561-596.
ABSTRACT: This study uses a well-established water balance methodology to evaluate the relative impact of global warming and soil degradation due to desertification on future African water resources. Using a baseline climatology, a GCM global warming scenario, a newly derived soil water-holding capacity data set, and a worldwide survey of soil degradation between 1950 and 1980, four climate and soil degradation scenarios are created to simulate the potential impact of global warming and soil degradation on African water resources for the 2010-2039 time period. Results indicate that, on a continental scale, the impact of global warming will be significantly greater than the impact of soil degradation. However, when only considering the locations where desertification is an issue (wet and dry climate regions), the potential effects of these two different human impacts on local water resources can be expected to be on the same order of magnitude. Drying associated with global warming is primarily the result of increased water demand (potential evapotranspiration) across the entire continent. While there are small increases in precipitation under global warming conditions, they are inadequate to meet the increased water demand. Soil degradation is most severe in highly populated, wet and dry climate regions and results in decreased water-holding capacities in these locations. This results in increased water surplus conditions during wet seasons when the soil's ability to absorb precipitation is reduced. At the same time, water deficits in these locations increase because of reduced soil water availability in the dry seasons. The net result of the combined scenarios is an intensification and extension of drought conditions during dry seasons.

Rosenzweig, C., and F.N. Tubiello. 1997. "Impacts of global climate change on Mediterranean agriculture: Current methodologies and future directions: An introductory essay," Mitigation and Adaptation Strategies for Global Change, Vol. 1, pp. 219-232.
ABSTRACT: Current trends in Mediterranean agriculture reveal differences between the Northern and Southern Mediterranean countries as related to population growth, land and water use, and food supply and demand. The changes in temperature and precipitation predicted by general circulation models for the Mediterranean region will affect water availability and resource management, critically shaping the patterns of future crop production. Three companion papers analyze in detail future impacts of predicted climate change on wheat (Triticum aestivum L.) and maize (Zea mays L.) production in Spain, Greece, and Egypt, and test farm-level adaptation strategies such as early planting and cultivar change with the aid of dynamic crop models. Strategies to improve the assessment of the potential effects of future climate change on agricultural production are discussed.

Schulze, Roland E., Gregory A. Kiker and Richard P. Kunz. 1993. "Global climate change and agricultural productivity in southern Africa," Global Environmental Change,
Vol. 3, No. 4, December, pp. 330-349.
ABSTRACT: An analysis tool was developed to simulate primary productivity and crop yields for both present and possible future climate conditions. Southern Africa was delineated into 712 relatively homogeneous climate zones, each with specific climate, soil and vegetation response information. The primary productivity and crop yield models were linked with the climate zones via a cellbased agrohydrologlcal model, with the final output coordinated using a Geographic Information System. The results of this preliminary study show a large dependence of production and crop yield on the intra-seasonal and inter-annual variation of rainfall. The most important conclusion from the study is the readiness of the developed tool and associated infrastructure for future analysis into social, technological and political responses to food security in southern Africa.

Downing, Thomas E. 1991. "Vulnerability to hunger in Africa: a climate change perspective,"
Global Environmental Change, Vol. 1, No. 5, December, pp. 365-380.
ABSTRACT: Limitations of present assessments of climate change impacts on food supplies are addressed, and a new approach is proposed. This uses the concept of vulnerability to hunger as a point of departure. A typology of vulnerability indices is developed and several measures of vulnerability are explored using information from case studies reported in the literature and research coordinated by the author's research group. An initial synthesis of data about climate change and vulnerability to hunger is illustrated for Africa.

Egypt

Yates, David N., and Kenneth M. Strzepek. 1998. "An Assessment of Integrated Climate Change Impacts on the Agricultural Economy of Egypt," Climatic Change, Vol. 38, No. 3, March, pp. 261-287.
ABSTRACT: This study used a quadratic programming sector model to assess the integrated impacts of climate change on the agricultural economy of Egypt. Results from a dynamic global food trade model were used to update the Egyptian sector model and included socio-economic trends and world market prices of agricultural goods. In addition, the impacts of climate change from three bio-physical sectors - water resources, crop yields, and land resources - were used as inputs to the economic model. The climate change scenarios generally had minor impacts on aggregated economic welfare (sum of Consumer and Producer Surplus or CPS), with the largest reduction of approximately 6 percent. In some climate change scenarios, CPS slightly improved or remained unchanged. These scenarios generally benefited consumers more than producers, as world market conditions reduced the revenue generating capacity of Egyptian agricultural exporters but decreased the costs of imports. Despite increased water availability and only moderate yield declines, several climate change scenarios showed producers being negatively affected by climate change. The analysis supported the hypothesis that smaller food importing countries are at a greater risk to climate change, and impacts could have as much to do with changes in world markets as with changes in local and regional biophysical systems and shifts in the national agricultural economy.

El-Shaer, H.M., C. Rosenzweig, A. Iglesias, M.H. Eid, and D. Hillel. 1997. "Impact of climate change on possible scenarios for Egyptian agriculture in the future," Mitigation and Adaptation Strategies for Global Change, Vol. 1, pp. 233-250.
ABSTRACT: If no timely measures are taken to adapt Egyptian agriculture to possible climate warming, the effects may be negative and serious. Egypt appears to be particularly vulnerable to climate change because of its dependence on the Nile River as the primary water source, its large traditional agricultural base, and its long coastline, already undergoing both intensifying development and erosion. A simulation study characterized potential yield and water use efficiency decreases on two reference crops in the main agricultural regions with possible future climatic variation, even when the beneficial effects of increase CO2 were taken into account. On-farm adaptation techniques which imply no additional cost to the agricultural system did not compensate for the yield losses with the warmer climate or improve the crop water-use efficiency. Economic adjustments such as the imporvement of the overall water-use efficiency of the agricultural system, soil drainage and conservation, land management, and crop alternatives are essential. If appropriate measures are taken, negative effects of climate change in agricultural production and other major resource sectors (water and land) may be lessened.

Niger

Mohamed, A. Ben, N. van Duivenbooden, and S. Abdoussallam. 2002. "Impact of Climate Change on Agricultural Production in the Sahel - Part 1. Methodological Approach and Case Study for Millet in Niger," Climatic Change, Vol. 54, No. 3, August, pp. 327-348.
ABSTRACT: In the last 30 years the climate of the West African Sahel has shown various changes, especially in terms of rainfall, of which inter-annual variability is very high. This has significant consequences for the poor-resource farmers, whose incomes depend mainly on rainfed agriculture. The West African Sahel is already known as an area characterized by important interaction between climate variability and key socio-economic sectors such as agriculture and water resources. More than 80% of the 55 million population of West African Sahel is rural, involved in agriculture and stock-farming, the two sectors contributing almost 35% of the countries' GDPs. It is therefore obvious that climate change seriously affects the economies of these countries. Adding to this situation the high rate of population increase (~3%), leading to progressive pressure upon ecosystems, and poor sanitary facilities, one comes to the conclusion that Sahelian countries, Niger amongst them, will be highly vulnerable to climate change. This paper investigates the impact of current climate variability and future climate change on millet production for three major millet-producing regions in Niger. Statistical models have been used to predict the effects of climate change on future production on the basis of thirteen available predictors. Based on the analysis of the past 30-years of rainfall and production data, the most significant predictors of the model are (i) sea surface temperature anomalies, (ii) the amount of rainfall in July, August and September, (iii) the number of rainy days and (iv) the wind erosion factor. In 2025, production of millet is estimated to be about 13% lower as a consequence of climate change, translated into a reduction of the total amount of rainfall for July, August and September, combined with an increase in temperature while maintaining other significant predictors at a constant level. Subsequently, various potential strategies to compensate this loss are evaluated, including those to increase water use efficiency and to cultivate varieties that are adapted to such circumstances.

N. van Duivenbooden, S. Abdoussalam, and A. Ben Mohamed. 2002. "Impact of Climate Change on Agricultural Production in the Sahel - Part 2. Case Study for Groundnut and Cowpea in Niger," Climatic Change, Vol. 54, No. 3, August, pp. 349-368.
ABSTRACT: During the last 30 years, the climate of the West African Sahel has undergone various changes, especially in terms of rainfall. This has large consequences for the poor-resource farmers depending mainly on rainfed agriculture. This paper investigates the impacts of current climate variability and future climate change on groundnut and cowpea production in Niger for three major agricultural regions, including the groundnut basin. Niger was one of the largest West African groundnut producing and exporting countries. Groundnut production - as a cash crop - dropped from about 312,000 tons in the mid 1960s (about 68% exported) to as low as 13,000 tons in 1988 and increased again to 110,000 tons in 2000. Cowpea, a food crop, shows a different tendency, going from 4,000 tons in the mid fifties to a maximum of 775,000 tons in 1997, and its cultivated area is still increasing. It is also a cash crop in local economies (especially for women). To highlight the impact of climate change on groundnut and cowpea production (significantly determined by rainfall in July, August and September), the following components of the rainfall regime were calculated for the period 1951-1998: mean annual and monthly rainfall, beginning, end and length of the rainy season, number of rainy days per month, amount of rainfall per rainy day and the maximum length of dry spell per month. Three sub-periods whose duration varied per region were defined: for Dosso 1951-1968, 1969-1984 and 1985-1998; for Maradi 1951-1970, 1971-1987 and 1988-1998; and for Zinder 1951-1966, 1967-1984 and 1985-1998. A change in rainfall regime components was observed between the three sub-periods, which were characterized in chronological order by wet, dry and intermediate conditions. To assess the impact of climate variability and change on groundnut and cowpea production, a statistical modeling approach has been followed, based on thirteen predictors as described and discussed in the preceding paper. Climate change is mimicked in terms of reduced total amount of rainfall for the three main rainfall months and an increased temperature, while maintaining other significant predictors at a constant level. In 2025, production of groundnut is estimated to be between 11 and 25% lower, while cowpea yield will fall maximally 30%. Various strategies to compensate this potential loss are presented for the two crops.

Asia

Murdiyarso, D. 2000. "Adaptation to Climatic Variability and Change: Asian Perspectives on Agriculture and Food Security," Environmental Monitoring and Assessment, Vol. 61, No. 1, March, pp. 123-131.
ABSTRACT: The impacts of climate change on potential rice production in Asia are reviewed in the light of the adaptation to climatic variability and change. Collaborative studies carried out by IRRI and US-EPA reported that using process-based crop simulation models increasing temperature may decrease rice potential yield up to 7.4% per degree increment of temperature. When climate scenarios predicted by GCMs were applied it was demonstrated that rice production in Asia may decline by 3.8% under the climates of the next century. Moreover, changes in rainfall pattern and distribution were also found suggesting the possible shift of agricultural lands in the region. The studies however have not taken the impacts of climatic variability into account, which often produce extreme events like that caused by monsoons and El Niño.
Shifts in rice-growing areas are likely to be constrained by land-use changes occurring for other developmental reasons, which may force greater cultivation of marginal lands and further deforestation. This should be taken into account and lead to more integrated assessment, especially in developing countries where land-use change is more a top-down policy rather than farmers' decision. A key question is: To what extent will improving the ability of societies to cope with current climatic variability through changing design of agricultural systems and practices help the same societies cope with the likely changes in climate?

Luo, Qunying, and Erda Lin. 1999. "Agricultural Vulnerability and Adaptation in Developing Countries: The Asia-Pacific Region," Climatic Change, Vol. 43, No. 4, December, pp. 729-743.
ABSTRACT: During the last decades, a large number of climate change impact studies on agriculture have been conducted qualitatively and quantitatively in many regions of the Asia-Pacific. Changes in average climate conditions and climate variability will have a significant consequence on crop yields in many parts of the Asia-Pacific. Crop yield and productivity changes will vary considerably across the region. Vulnerability to climate change depends not only on physical and biological response but also on socioeconomic characteristics. Adaptation strategies that consider changes in crop varieties or in the timing of agricultural activities imply low costs and, if readily undertaken, can compensate for some of the yield loss simulated with the climate change scenarios. The studies reviewed here suggest that the regions of Tropical Asia appear to be among the more vulnerable; some areas of Temperate Asia also appear to be vulnerable.

Iglesias, A., L. Erda, and C. Rosenzweig. 1996. "Climate change in Asia: A review of the vulnerability and adaptation of crop production," Water, Air, and Soil Pollution, Vol. 92, pp. 13-27.
ABSTRACT: A number of studies have provided quantitative assessments of the potential climate change impacts on crop production in Asia. Estimates take into account (a) uncertainty in the level of climate change expected, using a range of climate change scenarios; (b) physiological effects of carbon dioxide on the crops, and (c) different adaptive responses. In all cases, the efefcts of climate change induced by increased atmospheric carbon dioxide depended on the counteracting effects among higher daily evapotranspiration rates, shortening of crop growth duration, and changes in precipitation patterns, as well as the effects of carbon dioxide on crop growth and water-use efficiency. Although results varied depending on the geographical locations of the regions tested, the production of rice (the main food crop in the region) generally did not benefit from climate change. In South and Southeast Asia, there is concern about how climate change may affect El Niño/Souther Oscillation events, since these play a key role in determining agricultural production. Furthermore, problems arising from variability of water availability and soil degradation are currently major challenges to agriculture in the region. These problems may be exacerbated in the future if global climate change projections are realized. Many studies have considered strategies for improving agricultural management, based on the optimization of crop management decisions. Climate change analyses could be further strengthened by economic studies that integrate the potential use of natural resouces across sectors.

China

Erda L. 1996. "Agricultural vulnerability and adaptation to global warming in China," Water, Air, and Soil Pollution, Vol. 92, No. 1-2, pp. 63-73.
ABSTRACT: This paper discusses the vulnerability and adaptation of the agricultural sector of China to global warming. Based on a summarization of Chinese agricultural and general circulation model trends, adverse impacts on China's agriculture caused by a warming and drying climate were identified. Because of limited irrigation potential, the sustainable development of Chinese agriculture will be difficult. Six sensitive agricultural areas located on the edges of different agroecological zones, and seven provinces with high vulnerability to the impacts on agriculture, were studied. On the basis of an estimation of the potential supply of agricultural products and demand for food, the annual incremental costs for adaptation to climate change would be US $0.8-3.48 billion, without adaptation, the annual agricultural loss due to global warming would be US $1.37-79.98 billion from 2000 to 2050. Adaptive measures discussed include intensive management and the possibility of a tripartite structure of planting that would entail coordinated development of grain crops, feed crops, and cash crops.

Jinghua W., and L. Erda. 1996. "The impacts of potential climate change and climate variability on simulated maize production in China," Water, Air, and Soil Pollution, Vol. 92, No. 1-2, pp. 75-85.
ABSTRACT: This study assessed the impacts of potential climate change on maize yields in China, using the CERES-Maize model under rainfed and irrigated conditions, based on 35 maize modelling sites in eastern China that characterize the main maize regions. The Chinese Weather Generator was developed to generate a long time series of daily climate data as baseline climate for 51 sites in China. Climate change scenarios were created from three equilibrium general circulation models: the Geophysical Fluid Dynamics Laboratory model; the high-resolution United Kingdom Meteorological Office model; and the Max Planck Institute model. At most sites, simulated yields of both rainfed and irrigated maize decreased under climate change scenarios, primarily because of increases in temperature, which shorten maize growth duration, particularly the grain-filling period. Decreases of simulated yields varied across the GCM scenarios. Simulated yields increased at only a few northern sites, probably because maize growth is currently temperature-limited at these relatively high latitudes. To analyze the possible impacts of climate variability on maize yield, the authors specified incremental changes to variabilities of temperature and precipitation and applied these changes to the GCM scenarios to create sensitivity scenarios. Arbitrary climate variability sensitivity tests were conducted at three sites in the North China Plain to test maize model response to a range of changes (0, +10, and +20) in the monthly standard deviations of temperature and monthly variation coefficients of precipitation. The results from the three sites showed the incremental climate variability caused simulated yield decreases, and the decreases in rainfed yield were greater than those of irrigated yield.

Smit B., and C. Yunlong. 1996. "Climate change and agriculture in China," Global Environmental Change, Vol. 6, No. 3, pp. 205-214.
ABSTRACT: The implications of climate change for agriculture and food are global concerns, and they are very important for China. The country depends on an agricultural system, which has evolved over thousands of years, to intensively exploit environmental conditions. The pressures on the resource base are accentuated by the prospect of climate change. This paper synthesizes information from a variety of studies on Chinese agriculture and climate. Historical studies document the impacts of past climate changes and extremes, and the types of adjustments which have occurred, the vulnerability of Chinese agriculture to climate change. Climate change scenarios are assessed relative to the current distribution of agro-climatic regions and farming systems. Notwithstanding the yield-enhancing effects of warming and elevated carbon dioxide levels, expected moisture deficits and uncertain changes in the timing and frequency of critical conditions indicate that there are serious threats to the stability and adaptability of China's food production system.

India

Kumar, K. S. Kavi, and Jyoti Parikh. 2001. "Indian agriculture and climate sensitivity," Global Environmental Change, Vol. 11, No. 2, July, pp. 147-154.
ABSTRACT: This study estimates the relationship between farm level net-revenue and climate variables in India using cross-sectional evidence. Using the observed reactions of farmers, the study seeks to understand how they have adapted to different climatic conditions across India. District level data is used for the analysis. The study also explores the influence of annual weather and crop prices on the climate response function. The estimated climate response function is used to assess the possible impacts of a `best-guess' climate change scenario on Indian agriculture.

Saseendran S. A., K.K. Singh, L.S. Rathore, S.V. Singh, and S.K. Sinha. 2000. "Effects of climate change on rice production in the tropical humid climate of Kerala, India," Climatic Change, Vol. 44, No. 4, pp. 459-514.
ABSTRACT: The plausible climate change scenario for the Indian subcontinent, as expected by the middle of the next century, taking into account the projected emissions of greenhouse gases and sulphate aerosols, in a coupled atmosphere-ocean model experiment performed at Deutsches Klimarechenzentrum, Germany, is adopted for the study - which used the CERES-Rice v3. crop simulation model, calibrated and validated for suitability. The adopted scenario represented an approximately 1.5 °C increase in monsoon seasonal mean surface temperature, and a 2 mm increase in rainfall per day, between 2040-2049 with respect to the 1980s. The IPCC (Intergovernmental Panel on Climate Change) business-as-usual scenario projection of plant usable concentration of CO2 about 460 PPM by the middle of this century, are also used in the crop model simulation. The sensitivity experiments of the rice model to CO2 concentration changes indicated that over Kerala, an increase in CO2 concentration leads to yield-increase due to its fertilization effect and also enhances the water-use efficiency of the paddy.

Indonesia

Amien, Istiqlal, Popi Redjekiningrum, Budi Kartiwa, and Woro Estiningtyas. 1999. "Simulated rice yields as affected by interannual climate variability and possible climate change in Java," Climate Research, Vol. 12, pp. 145-152.
ABSTRACT: About 60% of the rice produced in Indonesia is grown in the fertile soils of the island of Java. Introduction of the high-yielding rice varieties and improvement of cultural technique have increased rice production, and self-sufficiency was attained in 1984. However, increasing population and decreasing land for rice cultivation could threaten the food supply in the country. Rice production is also threatened by interannual climate variability and possible climate change. To provide policy-makers and planners with information to formulate a strategy to cope with interannual climate variability and the possible climate change, rice yields of 2 production areas on Java were simulated using the DSSAT (Decision Support System for Agrotechnology Transfer) rice growth simulation model. The crop model predicted lower rice yields for different management options, compared with experiment plots, but predicted yields similar to or slightly higher than the farmers' yield. In general, the predictions relate quite well. The GISS, GFDL, and UKMO climate models predicted higher rainfall, solar radiation, and temperature in both locations. In the higher rainfall and lower temperature of the West Java site, the climate change scenarios reduced rice grain yield in both the first and second crops. During normal years in the relatively warmer and dryer climate of the East Java site, there was no significant yield reduction due to climate change, except under the UKMO scenario in the second crop. Because high temperature and CO2 concentration favor rice growth, development of more heat-tolerant varieties probably can compensate for the yield losses due to climate change in the future. Except for the GISS and GFDL climate scenarios in the first crop and the baseline climate scenario in the second crop in the West Java site, higher yield losses were predicted because of interannual climate variability. Since the dry spell threat is more imminent and frequent, to improve preparedness a short-term climate prediction for the tropical region is urgently needed.

Amien I et al. 1996. "Effects of interannual climate variability and climate change on rice yield in Java, Indonesia." Water, Air, and Soil Pollution, Vol. 92, No. 1-2, pp. 29-39.
ABSTRACT: About 60% of the nearly 40 x 106 tonnes of rice produced in Indonesia is from the island of Java. However, the rice self-sufficiency that has been attained and maintained since 1984 has been affected by climate variability effects of the El-Nino/Southern Oscillation phenomenon and could be threatened by changing climate. To aid policy-makers and planners in formulating strategic policy options, the effects of recurring droughts and possible climate change on rice yields were studied using climate and crop models. Three models were used to simulate climate change: those of the Goddard Institute for Space Studies; Geophysical Fluid Dynamics Laboratory; and the United Kingdom Meteorological Office. Several climate scenarios were generated for Ngawi in East Java, and Sukamandi in West Java. These models indicate that doubling GHG would increase solar radiation by a minimum 1.2%-2.1%, and transient climate change scenarios indicate that maximum and minimum temperatures would increase by 3.5% and 4.9%, in 2010, 6% and 9.8%, in 2030, and 11.1% and 15.7% respectively in 2050. The rainfall increase varies from 7% for West Java in 2010 to 8.7% for East Java in 2050. The Decision Support System for Agrotechnology Transfer crop model slightly under-predicts lowland rice yields of several experimental plots in three sites in Java and one site in Sumatra, but the results are almost equal to or a little higher than farm-level yields. Nevertheless, the simulation outputs and experimental plots yields are closely related with a coefficient of determination value of 87%. Changes in climate in the decades of 2010, 2030, and 2050 could drastically reduce rice yields: the rice yield is estimated to decrease by about one per cent annually in East Java and less in West Java. Currently, the rice yields in dry years are about one-half those of normal years.

Taiwan

Yu, Pao-Shan,Tao-Chang Yang, and Chien-Chih Chou. 2002. "Effects of Climate Change on Evapotranspiration from Paddy Fields in Southern Taiwan," Climatic Change, Vol. 54, No. 1-2, July, pp. 165-179.
ABSTRACT: The major objective of this study was to investigate the effects of climate change on evapotranspiration from paddy fields. A sensitivity analysis of meteorological variables at the Kao-Hsiung station, one of meteorological stations in southern Taiwan, was carried out using the modified Penman formula. Forty-eight-year records of temperature, relative humidity, sunshine duration, wind speed, and precipitation depth comprised the database. Trend and persistence analyses of the data were performed using the Mann-Kendall test, the Cumulative Deviation test, Linear Regression, and the Autocorrelation Coefficient. The results indicated that only temperature and relative humidity have significant long-term trends and persistence. Two climatic scenarios, viz. (1) linear extrapolation of climatic trends and (2) the predictions of General Circulation Models (GCMs), were assumed to investigate the effects of climate change on evapotranspiration. The study revealed that evapotranspiration from paddy fields increased under both climatic scenarios studied.

Australasia

Australia

Meinke, H., R. C. Stone, G. L. Hammer. 1996. "SOI Phases and Climatic Risk to Peanut Production: A Case Study for Northern Australia," International Journal of Climatology, Vol. 16, No. 7, pp. 783-789.
ABSTRACT: Phases of the Southern Oscillation Index (SOI) in August/ September are used in conjunction with a dynamic peanut simulation model to quantify climatic risk to peanut production in northern Australia. Specifically, we demonstrate how a simulation model can assist to forward estimate production risk based on historic climate records and known atmospheric conditions prior to planting a crop. The SOI phase analysis provides skill in assessing future rainfall probability distributions during the growing season and thus allows an estimate of likely crop performance. Such knowledge can provide valuable information for producers and processors. For instance, the analysis shows that for negative SOI patterns prior to sowing the expected median yield potential for dryland peanut production in northern Australia is 1 25 t ha-1 or 27 per cent below the long- term median. Conversely, a positive SOI pattern shows a median potential yield of 2 11 t ha-1, an increase of 23 per cent over the long-term median. Other production variables, such as date and frequency of planting opportunities, also differ significantly depending on SOI patterns.

New Zealand

G. J. Kenny, R. A. Warrick, B. D. Campbell, et al. 2000. "Investigating Climate Change Impacts and Thresholds: An Application of the CLIMPACTS Integrated Assessment Model for New Zealand Agriculture," Climatic Change, Vol. 46, No. 1-2, July, pp. 91-113.
ABSTRACT: The determination of `critical thresholds' is an essential task for informed policy decisions on establishing greenhouse gas emission targets. This paper presents a framework for determining critical thresholds for New Zealand agriculture, focusing on three agricultural crops - kiwifruit, grain maize, and Paspalum dilatatum - as exemplars for the fruit production, arable cropping and dairy production industries in New Zealand. The approach is based on the application of a country-scale, integrated assessment model, called CLIMPACTS. The CLIMPACTS system contains a climate change scenario generator, climate and land data, and sectoral impact models. Importantly, CLIMPACTS allows time-dependent assessments of climate change and its effects, which facilitates the identification and examination of thresholds, which largely relate to spatial changes, over time, in regions of economic importance for these crops. However, whether such thresholds are `critical' for New Zealand cannot currently be addressed by the CLIMPACTS model. The determination of `criticality' requires a fully integrated assessment in which the social, economic, and environmental costs and risks associated with these thresholds are comprehensively evaluated.

Europe

Jones, P. D., D. H. Lister, K. W. Jaggard, and J. D. Pidgeon. 2003. "Future Climate Impact on the Productivity of Sugar Beet (Beta vulgaris L.) in Europe," Climatic Change, Vol. 58, No. 1-2, May, pp. 93-108.
ABSTRACT: The impact of future climate change on sugar beet yields is assessed over western Europe using future (2021-2050) climate scenario data from a General Circulation Model (GCM) and the Broom's Barn simulation model of rain-fed crop growth and yield. GCM output for the 1961-1990 period is first compared with observed climate data and shown to be reliable for regions west of 24° E. Comparisons east of this meridian were less reliable with this GCM (HadCM2) and so were omitted from simulations of crop yield. Climate change is expected to bring yield increases of around 1 t/ha of sugar in northern Europe with decreases of a similar magnitude in northern France, Belgium and west/central Poland, for the period 2021-2050. Averaged for the study area (weighted by current regional production), yields show no overall change due to changed climate. However, this figure masks significant increases in yield potential (due to accelerated growth in warmer springs) and in losses due to drought stress. Drought losses are predicted to approximately double in areas with an existing problem and to become a serious new problem in NE France and Belgium. Overall west and central Europe simulated average drought losses rise from 7% (1961-1990) to 18% (2021-2050). The annual variability of yield (as measured by the coefficient of variation) will increase by half, from 10% to 15% compared to 1961-1990, again with potentially serious consequences for the sugar industry. The importance of crop breeding for drought tolerance is further emphasised. These changes are independent of the 9% yield increase which we estimate, on the basis of work by Demmers-Derks et al. (1998), is the likely direct effect of the increase in atmospheric CO2 concentration by 2021-2050.

Rosenzweig, C., and F.N. Tubiello. 1997. "Impacts of global climate change on Mediterranean agriculture: Current methodologies and future directions: An introductory essay," Mitigation and Adaptation Strategies for Global Change, Vol. 1, pp. 219-232.
ABSTRACT: Current trends in Mediterranean agriculture reveal differences between the Northern and Southern Mediterranean countries as related to population growth, land and water use, and food supply and demand. The changes in temperature and precipitation predicted by general circulation models for the Mediterranean region will affect water availability and resource management, critically shaping the patterns of future crop production. Three companion papers analyze in detail future impacts of predicted climate change on wheat (Triticum aestivum L.) and maize (Zea mays L.) production in Spain, Greece, and Egypt, and test farm-level adaptation strategies such as early planting and cultivar change with the aid of dynamic crop models. Strategies to improve the assessment of the potential effects of future climate change on agricultural production are discussed.

Carter, T. R., J. H. Porter, and M. L. Parry. 1991. "Climatic warming and crop potential in Europe: Prospects and uncertainties," Global Environmental Change, Vol. 1, No. 4, September, pp. 291-312.
ABSTRACT: Climatic warming due to increased concentrations of greenhouse gases in the atmosphere is likely to lead to largescale shifts in the pattern of agricultural potential. This article reports the results of a study to Investigate the broad-scale sensitivity of crop potential to climatic change in Europe. A simple agroclimatic index, effective temperature sum (ETS), has been related to the minimum requirements for the successful cultivation of three crops: grain maize, sunflower and soya bean. With the aid of a computer mapping system, ETS has been mapped across Europe on the basis of present climate and of scenarios of future climate. In this way, the effects of changes in climate can be expressed as spatial shifts in the limits of crop potential, and the uncertainities in the estimates can be interpreted in terms of the likelihood of particular regions becoming climatically suitable for crop cultivation. The estimates point to a considerable dislocation of agricultural potential occurring over a matter of only several decades.

Bulgaria

Alexandrov, Vesselin. 1999. "Vulnerability and adaptation of agronomic systems in Bulgaria," Climate Research, Vol. 12, No. 2-3, pp. 161-173.
ABSTRACT: Vulnerability and adaptation assessments of major agricultural crops under climate change were carried out in Bulgaria through the US Country Studies Program. Several climate change scenarios using General Circulation Model (GCM) outputs were created. Annual temperatures in the country are projected to rise between 2.9 (HCGS model) and 5.8°C (UK89 model) under effective doubling of CO2. Precipitation is expected to increase during the winter and to decrease during the warm half of the year. Under equilibrium 2 x CO2, the GCM climate change scenarios project an increase in the agroclimatic potential; however, warming would cause decreases in grain yield of winter wheat Triticum aestivum L. and especially maize Zea mays L. Simulated adaptation measures--such as zoning of crop production in agricultural land areas with elevation below 1000 m, changing planting dates, altering varieties, changing optimum value and dates of fertilizer application, and irrigation--were considered as potential responses that may modify any effects of climate change on crop production in Bulgaria. An action plan in Bulgarian agriculture under climate change was developed in cooperation with the Ministry of Agriculture, Forest and Agrarian Reform. Major points of the plan are a decrease in greenhouse gas emissions (reducing methane emissions produced by biological fermentation in stock breeding and rice cultivation; decreasing methane emissions by effective utilization of manure; improving fertilization using mineral fertilizers; decreasing the carbon emissions containing gasses; and retaining soil carbon) and some adaptation measures.

Alexandrov, Vesselin A. 1997. "Vulnerability of Agronomic Systems in Bulgaria," Climatic Change, Vol. 36, No. 1-2, May - June, pp. 135-149.
ABSTRACT: In recent years the problem of climate and its variations under the influence of natural processes and factors of anthropogenetic origin has come to the forefront of scientific and practical problems on a world-wide scale. Climate change vulnerability assessments of agronomic systems in Bulgaria have been initiated. In this paper preliminary results of this study are presented. Different climate change scenarios were defined. Global circulation model (GCM) scenarios and incremental scenarios for Bulgaria were created and applied. The influence of climate change on potential crop growing season above a base of 5° and 10 °C in Bulgaria was investigated. Increases in temperature can be expected to lengthen the potential growing season, resulting in a shift of thermal limits of agriculture in Bulgaria. The Decision Support System for Agrotechnology Transfer (DSSAT) Version 2.1 was used to assess the influence of climate change on grain yield of maize and winter wheat. Maize and winter wheat yields decreased with increasing temperatures and decreasing precipitation.

Greece

Kapetanaki, G., and C. Rosenzweig. 1997. "Impact of climate change on maize yield in central and northern Greece: A simulation study with CERES-Maize," Mitigation and Adaptation Strategies for Global Change, Vol. 1, pp. 251-271.
ABSTRACT: The potential impacts of climate change on the phenology and yield of two maize varieties in Greece were studied. Three sites representing the central and northern agricultural regions were selected: Karditsa, Naoussa and Xanthi. The CRES-Maize model, embedded in the Decision Support System for Agrotechnology Transfer (DSSAT 3.0), was used for the crop simulations, with current and possible future management practices. Equilibrium doubled CO2 climate change scenarios were derived from the GISS, GFDL, and UKMO general circulation models (GCMs); a transient scenario was developed from the GISS GCM transient run A. These scenarios predict consistent increases in air temperature, small increases in solar radiation and precipitation changes that vary considerably over the study regions in Greece. Physiological effects of CO2 on crop growth and yield were simulated. Under present management practices, the climate change scenarios generally resulted in decreases in maize yield due to reduced duration of the growing period at all sites. Adaptation analyses showed that mitigation of climate change effects may be achieved through earlier sowing dates and the use of new maize varieties. Varieties with higher kernel-filling rates, currently restricted to the central regions, could be extended to the northern regions of Greece. In the central regions, new maize varieties with longer grain-filling periods might be needed.

Poland

Demidowicz, G., T. Deputat, T. Górski, S. Krasowicz, and J. Kus. 2000. "Adaptation Scenarios of Agriculture in Poland to Future Climate Changes," Environmental Monitoring and Assessment, Vol. 61, No. 1, March, pp. 133-144.
ABSTRACT: This paper demonstrates the ability of Polish agriculture to adapt to predicted climate change according to GISS and GFDL scenarios. Both climate-change scenarios will significantly affect farming conditions in Poland through water deficit, shifts in planting and harvesting seasons, changes in crop yields and crop structure. Neither scenario seems to endanger the self-sufficiency of Poland as long as preventative measures are taken. Moreover, the realization of GISS creates the possibility of a surplus in production. It must be emphasized that regardless of the scenario, the adaptation of agriculture to an expected climate change cannot be handled by the farming community itself.

Romania

Cuculeanu, Vasile, Adriana Marica, and Catalin Simota. 1999. "Climate change impact on agricultural crops and adaptation options in Romania," Climate Research, Vol. 12, No. 2-3, pp.153-160.
ABSTRACT: The aim of this paper is to assess the potential effects of climate change on development, grain yield, and water balance for the main agricultural crops at 5 typical sites located in one of the most vulnerable zones of Romania. In addition, the paper evaluates possible adaptation measures of crop management to future climate changes. The vulnerability assessments focused on winter wheat and maize crops due to the particular importance of these crops in the cultivated areas and the difference in the genetic type of these crops reflected in their distinct physiological responses to CO2 concentration level (winter wheat is a C3 crop, while maize is a C4 crop). Outputs from 2 equilibrium 2 x CO2 general circulation models were used to develop climate change scenarios. CERES simulation models, linked with a seasonal analysis program included in the dedicated software DSSAT v3.0, were run for 30 yr with baseline climate and climate change scenarios. The results of crop simulations under climate change scenarios indicated that winter wheat benefits from the interaction of double CO2 concentrations and higher temperatures, while irrigated maize in southern Romania shows negative responses to climate change. The adverse impact of climate change on the maize crop can be lessened by using a longer maturing hybrid, sowing in the last week of April, applying a plant density of 5 plants m-2, and increasing fertilization levels.

Russia

Sirotenko, Oleg D., Helena V. Abashina, Vera N. Pavlova. 1997. "Sensitivity of the Russian Agriculture to Changes in Climate, CO2 and Tropospheric Ozone Concentrations and Soil Fertility," Climatic Change, Vol. 36, No. 1-2, May - June, pp. 217-232.
ABSTRACT: Russian agriculture sensitivity to changes in climate, soil and atmosphere chemistry were analyzed. Calculated data are presented on crop productivity of grain crops and grasses (C3) under arid and humid scenarios of climate taking account of one-, two-, three and four-factor natural environment impacts. All four factors under studies (climatic parameters, CO2 and tropospheric ozone concentrations, soil degradation extent) greatly impact agriculture productivity. The effect of interaction between all considered factors on agroecosystem productivity is studied. It is established that a simple additive scheme for explaining the complex effect of some factors can be much violated. In this case, not only variations in the mean crop yield levels but also variations in the degree of crop stability have been assessed in some regions, that may be more important for determining the social-economic consequences. It turned out that the recurrence of critically very low yields in steppe regions may increase two fold as a result of global warming.

Spain

Iglesias, Ana, Cynthia Rosenzweigb and David Pereira. 2000. "Agricultural impacts of climate change in Spain: developing tools for a spatial analysis," Global Environmental Change, Vol. 10, No. 1, April 2000, p. 69-80.
ABSTRACT: CERES-Wheat, a dynamic process crop growth model, is specified and validated for seven sites in the major wheat-growing regions of Spain. Variables explaining a significant proportion of simulated yield variance are crop water (sum of precipitation and irrigation) and temperature during the growing season. A multiple linear regression model is developed to represent simulated yield response to these variables. Seven agro-climatic regions are defined based on K-mean cluster analysis of temperature and precipitation data from 329 meteorological stations and provincial crop yield data. The yield functions derived from the validated crop model were then used with the gridded agro-climatic database to conduct a spatial analysis of climate change impacts on national wheat production. Climate change scenarios with and without sulfate aerosols developed from the Hadley Centre (HCGG and HCGS) and Canadian Climate Centre (CCGG and CCGC) are tested.

Turkey

Komuscu, Ali Umran, Ayhan Erkan, and Sukriye Oz. 1998. "Possible Impacts of Climate Change on Soil Moisture Availability in the Southeast Anatolia Development Project Region (GAP): An Analysis from an Agricultural Drought Perspective," Climatic Change, Vol. 40, No. 3-4, December, pp. 519-545.
ABSTRACT: This paper presents probable effects of climate change on soil moisture availability in the Southeast Anatolia Development Project (GAP) region of Turkey. A series of hypothetical climate change scenarios and GCM-generated IPCC Business-as-Usual scenario estimates of temperature and precipitation changes were used to examine implications of climate change for seasonal changes in actual evapotranspiration, soil moisture deficit, and soil moisture surplus in 13 subregions of the GAP. Of particular importance are predicted patterns of enhancement in summer soil moisture deficit that are consistent across the region in all scenarios. Least effect of the projected warming on the soil moisture deficit enhancement is observed with the IPCC estimates. The projected temperature changes would be responsible for a great portion of the enhancement in summer deficits in the GAP region. The increase in precipitation had less effect on depletion rate of soil moisture when the temperatures increase. Particularly southern and southeastern parts of the region will suffer severe moisture shortages during summer. Winter surplus decreased in scenarios with increased temperature and decreased precipitation in most cases. Even when precipitation was not changed, total annual surplus decreased by 4 percent to 43 percent for a 2°C warming and by 8 percent to 91 percent for a 4°C warming. These hydrologic results may have significant implications for water availability in the GAP as the present project evaluations lack climate change analysis. Adaptation strategies - such as changes in crop varieties, applying more advanced dry farming methods, improved water management, developing more efficient irrigation systems, and changes in planting - will be important in limiting adverse effects and taking advantage of beneficial changes in climate.

United Kingdom

Ghaffari, A., H. F. Cook, and H. C. Lee. 2002. "Climate Change and Winter Wheat Management: A Modelling Scenario for South-Eastern England," Climatic Change, Vol. 55, No. 4, December, pp. 509-533.
ABSTRACT: Crop models are useful tools for assessing the impact of climate change on crop production. The dynamic crop-growth model, CERES-Wheat is used to examine crop management responses, including yield, under six climate change scenarios for the years 2025 and 2050 on the Estate of Imperial College at Wye, Kent, U.K. Sensitivity analysis shows a dry matter yield decrease in response to increases in temperature alone. CERES-Wheat was then constrained to assess the crop performance under water-limited production scenarios with different soils, and the results show that crop grain yield actually increases, largely due to CO2 fertilisation leading to increased rates of photosynthesis. Different management practices (planting dates and nitrogen application) were applied to find the best adaptation strategies. In general, `early' sowing (10th September) had the highest simulated yield, and `late' sowing (10th November) the lowest. For the soils tested, the highest and sustained crop production was obtained from Hamble soils (silt loam) compared with either the Fyfield (sandy) or Denchworth (clay). Adding nitrogen and other fertilisers would likely be necessary to take full advantage of the CO2 fertilisation effect and to compensate, in some cases, for yield losses caused by climate change where water shortage becomes serious.

Naden, P. S. and C. D. Watts. 2001. "Estimating Climate-Induced Change in Soil Moisture at the Landscape Scale: An Application to Five Areas of Ecological Interest in the U.K.," Climatic Change, Vol. 49, No. 4, June, pp. 411-440.
ABSTRACT: This paper presents an indication of the possible effects of climate change on monthly mean soil moisture at a fine spatial resolution (50 m) over the scale of a landscape (100-250 km2). Soil moisture is modelled using daily time series of rainfall and potential evapotranspiration to drive a simple hydrological model operating on individual hillslopes and explicitly including, on a conceptual level, the lateral movement of water. Climate change is represented by the UKTR scenario and model results are provided at two time slices (the years 2030-2040 and 2060-2070) for five areas of ecological interest, forming a north-south transect across the U.K. The results are given in terms of the distribution of the monthly mean soil moisture change by soil type. The spread of values reflects the effect of the topographic control on the lateral movement of water. The results show a small increase in wetness at the Cairngorm site, a very slight decrease in summer soil moisture at the Moor House site and a very marked fall in soil moisture for the three more southerly sites. The importance of soil type in determining the availability of water to plants, the changing areal extent above specified soil moisture thresholds, and the implications for ecological change and conservation are discussed.

McMaster, H. J. 1999. "The Potential Impact of Global Warming on Hail Losses to Winter Cereal Crops in New South Wales," Climatic Change, Vol. 43, No. 2, October, pp. 455-476.
ABSTRACT: This study was undertaken to determine the impact of potential global warming on the magnitude of hail losses to winter cereal crops within two areas situated on the western slopes of New South Wales, Australia. A model relating historical crop hail losses to climatic variables was developed for each area. These models included seasonal measures of vertical instability, low-level moisture and the height of the freezing level. In both areas, windshear was not found to be an important factor influencing seasonal crop hail losses. The two crop hail loss models were then used in conjunction with upper-air climatic data from three single mixed-layer global climate models (GCMs). Each GCM was run for 1 × CO2 conditions and for 2 × CO2 conditions. The enhanced greenhouse effect on climatic variables was taken to be the difference between their values for these two runs. Changes to climatic variables were then translated directly into changes in the percentage value of the winter cereal crop lost due to hail. In both areas, the three GCMs agreed concerning the direction of change in each of the variables used in the crop hail loss model. GCM simulations of the greenhouse effect resulted in a decline in winter cereal crop hail losses, with the exception of one GCM simulation at one location where losses increased slightly. None of the changes due to the enhanced greenhouse effect, however, were significant owing to a large observed seasonal variability of crop hail losses. Also, the simulated seasonal variability of crop hail losses did not change significantly due to the enhanced greenhouse effect. These results depended on two important assumptions. Firstly, it was assumed that the dominant relationships between climatic variables and crop hail losses in the past would remain the same in a future climate. Secondly, it was assumed that the single mixed-layer GCMs used in the study were correctly predicting climate change under enhanced greenhouse conditions.

Latin America

Jones, Peter G., and Philip K. Thornton. 2003. "The potential impacts of climate change on maize production in Africa and Latin America in 2055," Global Environmental Change, Vol. 13, No. 1, pp. 51 - 59.
ABSTRACT: The impacts of climate change on agriculture may add significantly to the development challenges of ensuring food security and reducing poverty. We show the possible impacts on maize production in Africa and Latin America to 2055, using high-resolution methods to generate characteristic daily weather data for driving a detailed simulation model of the maize crop. Although the results indicate an overall reduction of only 10% in maize production to 2055, equivalent to losses of $2 billion per year, the aggregate results hide enormous variability: areas can be identified where maize yields may change substantially. Climate change urgently needs to be assessed at the level of the household, so that poor and vulnerable people dependent on agriculture can be appropriately targeted in research and development activities whose object is poverty alleviation.

Baethgen, Walter E. 1997. "Vulnerability of the agricultural sector of Latin America to climate change," Climate Research, Vol. 9, No. 1-2, December 29, pp. 1-7.
ABSTRACT: The vulnerability of the agricultural sector in any region to future possible climate-change scenarios is determined to a great extent by the vulnerability of the sector to current climatic, economic and policy scenarios. Agricultural systems which are currently subject to extreme climatic interannual variability (drought, flood, storms, etc.) are likely to become even more vulnerable under the most commonly expected scenarios of climate change (i.e. increased temperatures, increased rainfall variability). Similarly, agricultural systems which are currently subject to drastic changes in economic and policy scenarios are also prone to become more vulnerable under expected climate-change conditions. The agricultural sector of Latin America has been subject to important variations in economical conditions and policies. These conditions have affected the structure of agricultural production, and resulted in a large reduction of the number of small farmers, who have migrated to poor metropolitan areas. Even for larger, commercial farmers, unstable and often inconsistent agricultural policies have increased the vulnerability of the sector. Additionally, large areas of Latin America are already affected by current interannual climatic variability related to the length of rainy seasons and the occurrence of extreme events (droughts, floods, etc.). The few studies conducted in the region to specifically assess the impact of climate change on agriculture have revealed expected reductions and increased variability in crop productivity. Similar results should be expected in the vast regions devoted to livestock production, since the systems are based on a fragile balance of nutrients, available water, stocking rates and pasture species. The characteristics of the current situation described in this article demonstrate the vulnerability of Latin American agriculture to climate change. Preparing the agricultural sector to mitigate the potential negative effects of climate change will require strong and consistent efforts in both the scientific and policy sectors of the region.

Argentina

Díaz, Raúl A., Graciela O. Magrin, María I. Travasso, and Rafael O. Rodríguez. 1997. "Climate change and its impact on the properties of agricultural soils in the Argentinean Rolling Pampas," Climate Research, Vol. 9, No. 1-2, December 29, pp. 25-30.
ABSTRACT: The agriculture of the Argentinean pampean region is undergoing a reconversion process as a result of a more intensive use of agrotechnologies. The ongoing changes are likely to overlap with the greenhouse warming-related climatic changes and atmospheric CO2 increase predicted for the next century. The goal of this study is to assess the potential impact of such changes on certain properties of soils of the Rolling Pampas, which support 10 to 15% of the national grain crop and oilseed production. Rotation of wheat/soybean-maize crops in 45 agricultural soils was simulated using the EPIC model (Erosion/Productivity Impact Calculator; US Dept of Agriculture), which was previously calibrated and validated for local conditions, for the 1996 to 2050 period under 2 scenarios: (1) no climate change, and (2) climate change conditions derived from regional climate parameters projected by the GISS general circulation model combined with a CO2 concentration of 550 ppm. The 1971 to 1995 period was simulated under neutral conditions with the purpose of defining soil conditions for 1996. It was found that in the event of a change in climate, physical proporties would change to a lesser degree than chemical properties. The soil bulk density would decrease by 8% with respect to the baseline scenario in soils under risk of erosion. In contrast, since it was assumed that the erosive storm pattern would remain unchanged, there would be no variations in the erosion rate. A general decrease in potential soil fertility of 6 to 10% for total organic N and 7 to 20% for organic C would take place after a 55 yr period. The sustainability of certain soils of the Carcarañá River basin, particularly the Villa Eloísa series, would be at a higher risk.

Magrin, Graciela O., María I. Travasso, Raúl A. Díaz, and Rafael O. Rodríguez. 1997. "Vulnerability of the agricultural systems of Argentina to climate change," Climate Research, Vol. 9, No. 1-2, December 29, pp. 31-36.
ABSTRACT: Agricultural production is one of the pillars of the Argentinean economy. The contribution of this sector is expected to keep growing in the near future as a consequence of the current technological development trend. However, the projected changes in climate and in the atmospheric concentration of CO2 in the coming years is likely to affect the productivity of crops, thus causing an impact on the national economy. This paper addresses climate change impact on the production of the main crops of the Argentinean pampean region by means of crop growth and development simulation models for wheat, maize and soybean included in DSSAT v. 3.0 (Dension Support System for Agrotechnology Transfer, Univ. of Hawaii, Honolulu). The weather data used includes temperature, global solar radiation and precipitation values from 23 sites within the region (current climate conditions) and the corresponding GISS general circulation model projections for the year 2050 (future climate) with CO2 concentrations of 330 and 550 ppm respectively. According to the results obtained, a generalized increase in soybean yield and a decrease in maize yield would occur. Wheat yield is likely to increase in the southern and the western parts of the region and decrease towards the north. Wheat and soybean production in the pampean region would increase by 3.6 and 20.7% respectively, while maize production would be reduced by 16.5%.

Mexico

Eakin, Hallie. 2000. "Smallholder Maize Production and Climatic Risk: A Case Study from Mexico," Climatic Change, Vol. 45, No. 1, April, pp. 19-36.
ABSTRACT: The article explores the strategies employed by smallholder farmers in Mexico to cope with the affects of climatic variability, and how seasonal climate forecasts may assist these farmers in mitigating climatic risk. Recognizing that the decisions of smallholder farmers are intricately tied to the political-economic circumstances in which they operate, the article discusses how agricultural policy in Mexico affects the vulnerability of small-scale producers and may inhibit their ability to use climatic forecasts to their advantage. The article first reviews the literature on smallholder adaptation in Mexico, and discusses briefly policy and institutional issues affecting adaptation at the farm-level. Using the case of small-scale maize producers in Tlaxcala, Mexico, as an illustration, the article then argues that political-economic uncertainty outweighs climatic variability as a determinant of the production strategies of small-scale producers. In these circumstances, the farmers are unlikely to use new seasonal climate forecasts.

Conde, Cecilia, Diana Liverman, Margarita Flores, Rosa Ferrer, Raquel Araújo, et al. 1998. "Vulnerability of rainfed maize crops in Mexico to climate change," Climate Research, Vol. 9, No. 3, pp. 17-23.
ABSTRACT: The impacts of a potential climate change on rainfed maize crops in Mexico are analyzed. For that purpose, baseline scenarios based on current climate conditions and their relation with maize crop development were created. Climate change scenarios were further developed and the crop vulnerability under each scenario was assessed. Two methods were used to quantify vulnerability. In the first place, maps describing the suitability for crop production according to climate conditions were produced. The differences between the baseline and the climate change scenarios allowed for estimating the area of the country likely to be positively or negatively affected. Secondly, the CERES-Maize model was applied to estimate rainfed maize crop yields at 7 sites in Mexico under the baseline and climate change scenarios. Adaptive measures were proposed and their feasibility was assessed on the basis of a simple cost-benefit analysis.

Uruguay

Hareau, Annie, Raúl Hofstadter, and Andrés Saizar. 1999. "Vulnerability to climate change in Uruguay: potential impacts on the agricultural and coastal resource sectors and response capabilities," Climate Research, Vol. 12, No. 2-3, pp. 185-193.
ABSTRACT: Uruguay's economy is mostly based on the use of natural resources that are affected by the strongly variable climate conditions to which the country is exposed. Climate changes induced by greenhouse warming are likely to enhance the country's vulnerability to environmental phenomena and are thus a matter of concern. The analyses carried out, particularly regarding crops, grasslands, and coastal resources, have evidenced the need to develop advanced response strategies framed within sectoral development plans. The type and sign of the effect on crop production would vary, depending on the crop involved. Grassland production is likely to be favored by increased temperature conditions, while precipitation deficiencies or increased variability would be detrimental. The predicted changes in sea level, even the most conservative, would put at risk high capital value land and infrastructure along the Uruguayan coast. Since the coast is frequently affected by storms, the overall vulnerability would also be determined by changes in storm patterns. It was observed that while appropriate conditions are encountered at both the technical and political levels to address changes that may affect the agricultural sector, a considerable effort is required to develop integrated coastal zone management plans that combine general and private interests and include responses to climate change.

Víctora, Carlos, Aarón Kacevas, and Héctor Fiori. 1997. "Soil vulnerability in Uruguay: potential effects of an increase in erosive rainfall on soil loss," Climate Research, Vol. 9, No. 1-2, December 29, pp. 41-46.
ABSTRACT: Climate change is likely to modify rainfall patterns and their interaction with the soil. This paper addresses soil vulnerability in terms of soil loss resulting from increases in the amount of rainfall. Four agricultural soils from Uruguay were studied: 2 'Vertisol Rúptico' soils (Typic Pelluderts), 1 'Brunosol Subéutrico Típico' and 1 'Brunosol Subéutrico Lúvico' (Typic Argiudolls). A field rainfall simulator was used to produce rain events of controlled intensity. Three of the soils were exposed to a constant rain of 70 mm h-1, which is the intensity of 30 min erosive rain events with a return period of 2 yr. The remaining soil, which is characterized by a high infiltration rate, was exposed to 140 mm h-1 rain. A 20 mm rainfall was applied on soil previously wet to saturation of the A horizon. The surface was prepared as bare soil seedbed on natural slopes (which are 2 to 5% steep, depending on the soil). The results obtained were corrected for a constant slope according to the Universal Soil Loss Equation (USLE). Soil losses (in kg ha-1) for rainwater depths (amounts) of 5, 10, 15 and 20 mm respectively were: Vertisol (Serie Tala): 25, 136, 273 and 437; Vertisol (Serie Jesús María): 52, 291, 1233 and 2633; Brunosol (Serie Pando): 368, 961, 1725 and 2683; Brunosol (Serie Colonia Brause): 48, 60, 115 and 224. These results are indicative of: (1) a major difference in the degree of vulnerability among soils, and (2) an increase in the soil loss rate as a result of the increase in the amount of applied rainfall. The high sensitivity of the Uruguayan soils to climate-change-induced potential variations in rainfall pattern is thus confirmed.

North America

Rosenzweig, C. 1985. "Potential CO2-induced climate effects on North American wheat-producing regions," Climatic Change, Vol. 7, pp. 367-389.
ABSTARCT: The environmental requirements for growth of winter, spring, and fall-sown spring wheats in North America are specified and compared to temperature results from the control run of the Goddard Institute for Space Studies general circulation model (GISS GCM) and observed precipitation in order to generate a simulated map of current wheat production regions. The simulation agrees substantially with the actual map of wheat-growing regions in North America. Results from a doubled CO2 run of the climate model are then used to generate wheat regions under the new climatic conditions. In the simulation, areas of production increase in North America, particularly in Canada, due to increased growing degree units (GDU). Although wheat classifications may change, major wheat regions in the United States remain the same under simulated doubled CO2 conditions. The wheat-growing region of Mexico is identified as vulnerable due to high temperature stress. Higher mean temperatures during wheat growth, particularly during the reproductive stages, may increase the need for earlier-maturing, more heat-tolerant cultivars throughout North America. The soil moisture diagnostic of the climate model is used to analyze potential water availability in the major wheat region of the Southern Great Plain.

Canada

Weber, Marian and Grant Hauer. 2003. "A Regional Analysis of Climate Change Impacts on Canadian Agriculture," Canadian Public Policy, Vol. 29, No. 2, June, pp. 163-179.
ABSTRACT: Climate change is expected to alter production opportunities facing agricultural producers. Global studies of climate change impacts on agriculture suggest positive benefits for Canada. Results from Canadian studies tend to be more pessimistic; however, most of these studies are regionally specific and focus on the impacts on specific crops, particularly grains and oilseeds. This paper examines the impact of climate change on Canadian agricultural land values. Changes in land values are used to impute expected changes to agricultural GDP. We find that all provinces benefit from climate change and that previous estimates may be overly pessimistic.

Bryant, Christopher R., Barry Smit, Michael Brklacich, et al. 2000. "Adaptation in Canadian Agriculture to Climatic Variability and Change," Climatic Change, Vol. 45, No. 1, April, pp. 181-201.
ABSTRACT: The effects of climatic variability and change on Canadian agriculture have become an important research field since the early 1980s. In this paper, we seek to synthesize this research, focusing on agricultural adaptation, a purposeful proactive or reactive response to changes associated with climate, and influenced by many factors. A distinctive feature of methods used in research on adaptation in Canadian agriculture is the focus on the important role of human agency. Many individual farmers perceive they are well adapted to climate, because of their extensive 'technological' tool-kit, giving them confidence in dealing with climatic change. In many regions, little concern is expressed over climatic change, except where there are particular types of climatic vulnerability. Farmers respond to biophysical factors, including climate, as they interact with a complex of human factors. Several of these, notably institutional and political ones, have tended to diminish the farm-level risks stemming from climatic variability and change, but may well increase the long term vulnerability of Canadian agriculture. Notwithstanding the technological and management adaptation measures available to producers, Canadian agriculture remains vulnerable to climatic variability and to climate change.

Singh, Bhawan, Mustapha El Maayar, Pierre André, Christopher R. Bryant, and Jean-Pierre Thouez. 1998. "Impacts of a Ghg-Induced Climate Change on Crop Yields: Effects of Acceleration in Maturation, Moisture Stress and Optimal Temperature," Climatic Change, Vol. 38, No. 1, January, pp. 51-86.
ABSTRACT: The present study involves using the Canadian Climate Centre (CCC) climate change scenario to evaluate the impacts of a CO2-induced climate change on agriculture in Québec and vicinity. Climate change using the CCC General Circulation Model (GCM) data are fed into a crop model (FAO) so as to gauge the changes in agroclimatic factors such as growing season length and growing degree days, and subsequently potential yield changes for a variety of cereal (C3 and C4), leguminous, oleaginous, vegetable and special crops, for twelve major agricultural regions in southern Québec. Our results show that depending upon the agricultural zone and crop type, yields may increase (ex. corn and sorghum by 20%) or decrease (ex. wheat and soybean by 20 to 30%). Also, these crop yield changes appear to be related to acceleration in maturation rates, mainly to change in moisture stress and to shifts in optimal thermal growth conditions. These possible shifts in agricultural production potentials would solicit the formulation of appropriate adaptation strategies.

United States

Reilly, J., F. Tubiello, B. McCarl, D. Abler, R. Darwin, et al. 2003. "U.S. Agriculture and Climate Change: New Results," Climatic Change, Vol. 57, pp. 43-69. http://www.giss.nasa.gov/gpol/docs/2003/2003_ReillyTubiello.pdf.
ABSTRACT: We examined the impacts on U.S. agriculture of transient climate change as simulated by 2 global general circulation models focusing on the decades of the 2030s and 2090s. We examined historical shifts in the location of crops and trends in the variability of U.S. average crop yields, finding that non-climatic forces have likely dominated the north and westward movement of crops and the trends in yield variability. For the simulated future climates we considered impacts on crops, grazing and pasture, livestock, pesticide use, irrigation water supply and demand, and the sensitivity to international trade assumptions, finding that the aggregate of these effects were positive for the U.S. consumer but negative, due to declining crop prices, for producers. We examined the effects of potential changes in El Niño/Southern Oscillation (ENSO) and impacts on yield variability of changes in mean climate conditions. Increased losses occurred with ENSO intensity and frequency increases that could not be completely offset even if the events could be perfectly forecasted. Effects on yield variability of changes in mean temperatures were mixed. We also considered case study interactions of climate, agriculture, and the environment focusing on climate effects on nutrient loading to the Chesapeake Bay and groundwater depletion of the Edward's Aquifer that provides water for municipalities and agriculture to the San Antonio, Texas area. While only case studies, these results suggest environmental targets such as pumping limits and changes in farm practices to limit nutrient run-off would need to be tightened if current environmental goals were to be achieved under the climate scenarios we examined.

Abler, David, James Shortle, Jeffrey Carmichael, and Richard Horan. 2002. "Climate Change, Agriculture, and Water Quality in the Chesapeake Bay Region," Climatic Change, Vol. 55, No. 3, November, pp. 339-359.
ABSTRACT: Research on climate change and agriculture has largely focused on production, food prices, and producer incomes. However, societal interest in agriculture is much broader than these issues. The objective of this paper is to analyze the potential impacts of climate change on an important negative externality from agriculture, water quality. We construct a simulation model of maize production in twelve watersheds within the U.S. Chesapeake Bay Region that has economic and watershed components linking climate to productivity, production decisions by maize farmers, and nitrogen loadings delivered to the Chesapeake Bay. Maize is an important crop to study because of its importance to the region's agriculture and because it is a major source of nutrient pollution. The model is run under alternative scenarios regarding the future climate, future baseline (without any climate change), whether farmers respond to climate change, whether there are carbon dioxide (CO2) enrichment effects on maize production, and whether agricultural prices facing the region change due to climate change impacts on global agricultural commodity markets. The simulation results differ from one scenario to another on the magnitude and direction of change in nitrogen deliveries to the Chesapeake Bay. The results are highly sensitive to the choice of future baseline scenario and to whether there are CO2 enrichment effects. The results are also highly sensitive to assumptions about the impact of climate change on commodity prices facing farmers in the Chesapeake Bay region. The results indicate that economic responses by farmers to climate change definitely matter. Assuming that farmers do not respond to changes in temperature, precipitation, and atmospheric CO2 levels could lead to mistaken conclusions about the magnitude and direction of environmental impacts.

Rosenzweig, Cynthia, Francesco N. Tubiello, Richard Goldberg, Evan Mills, and Janine Bloomfield. 2002. "Increased crop damage in the US from excess precipitation under climate change," Global Environmental Change, Vol. 12, No. 3, October, pp. 197-202. http://eetd.lbl.gov/EMills/PUBS/PDF/Crops_GEC.pdf or http://www.giss.nasa.gov/gpol/docs/2002/2002_RosenzweigTubiello.pdf.
ABSTRACT: Recent flooding and heavy precipitation events in the US and worldwide have caused great damage to crop production. If the frequency of these weather extremes were to increase in the near future, as recent trends for the US indicate and as projected by global climate models (e.g., US National Assessment, Overview Report, 2001, The Potential Consequences of Climate Variability and Change, National Assesment Synthesis Team, US Global Change Research Program, Washington, DC; Houghton et al., 2001, IPCC Climate Change 2001: The Scientific Basis, Third Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, 335pp.), the cost of crop losses in the coming decades could rise dramatically. Yet current assessments of the impacts of climate change on agriculture have not quantified the negative effects on crop production from increased heavy precipitation and flooding (Impacts of climate change and variability on agriculture, in: US National Assessment Foundation Document, 2001. National Assessment Synthesis Team, US Global Change Research Program, Washington DC.). In this work, we modify a dynamic crop model in order to simulate one important effect of heavy precipitation on crop growth, plant damage from excess soil moisture. We compute that US corn production losses due to this factor, already significant under current climate, may double during the next thirty years, causing additional damages totaling an estimated $3 billion per year. These costs may either be borne directly by those impacted or transferred to private or governmental insurance and disaster relief programs.

Thomson, Allison M., Robert A. Brown, Steven J. Ghan, et al. 2002. "Elevation Dependence of Winter Wheat Production in Eastern Washington State with Climate Change: A Methodological Study," Climatic Change, Vol. 54, No. 1-2, July, pp. 141-164.
ABSTRACT: Crop growth models, used in climate change impact assessments to project production on a local scale, can obtain the daily weather information to drive them from models of the Earth's climate. General Circulation Models (GCMs), often used for this purpose, provide weather information for the entire globe but often cannot depict details of regional climates especially where complex topography plays an important role in weather patterns. The U.S. Pacific Northwest is an important wheat growing re