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Abstract: Ecophysiological models are widely used to forecast potential impacts of climate change on future agricultural productivity and to examine options for adaptation by local stakeholders and policy makers. However, protocols followed in such assessments vary to such an extent that they constrain cross-study syntheses and increase the potential for bias in projected impacts. We reviewed 221 peer-reviewed papers that used crop simulation models to examine diverse aspects of how climate change might affect agricultural systems. Six subject areas were examined: target crops and regions; the crop model(s) used and their characteristics; sources and application of data on [CO2] and climate; impact parameters evaluated; assessment of variability or risk; and adaptation strategies. Wheat, maize, soybean and rice were considered in approximately 170 papers. The USA (55 papers) and Europe (64 papers) were the dominant regions studied. The most frequent approach used to simulate response to CO2 involved adjusting daily radiation use efficiency (RUE) and transpiration, precluding consideration of the interacting effects of CO2, stomatal conductance and canopy temperature, which are expected to exacerbate effects of global warming. The assumed baseline [CO2] typically corresponded to conditions 10–30 years earlier than the date the paper was accepted, exaggerating the relative impacts of increased [CO2]. Due in part to the diverse scenarios for increases in greenhouse gas emissions, assumed future [CO2] also varied greatly, further complicating comparisons among studies. Papers considering adaptation predominantly examined changes in planting dates and cultivars; only 20 papers tested different tillage practices or crop rotations. Risk was quantified in over half the papers, mainly in relation to variability in yield or effects of water deficits, but the limited consideration of other factors affecting risk beside climate change per se suggests that impacts of climate change were overestimated relative to background variability. A coordinated crop, climate and soil data resource would allow researchers to focus on underlying science. More extensive model intercomparison, facilitated by modular software, should strengthen the biological realism of predictions and clarify the limits of our ability to forecast agricultural impacts of climate change on crop production and associated food security as well as to evaluate potential for adaptation. [Copyright &y& Elsevier]

Abstract: This paper examines the economic impact of climate change on livestock production in Kenya. We estimate a Ricardian model of net livestock incomes and further estimate the marginal impacts of climate change. We also simulate the impact of different climate scenarios on livestock incomes. The Ricardian results show that livestock production in Kenya is highly sensitive to climate change and that there is a non-linear relationship between climate change and livestock productivity. The estimated marginal impacts suggest modest gains from rising temperatures and losses from increased precipitation. The predictions from atmospheric ocean general circulation models suggest that livestock farmers in Kenya are likely to incur heavy losses from global warming. The highest and lowest losses are predicted from the Hadley Centre Coupled model (HADCM) and Parallel Climate Model (PCM) respectively, based on the Intergovernmental Panel on Climate Change A2 Special Report on Emissions Scenarios. The paper concludes that in the long term, climate change is likely to lead to increased poverty, vulnerability and loss of livelihoods. Several policy interventions are recommended to counter this impact. [Copyright &y& Elsevier]

Abstract: The south-west of Australia is being affected by a warming, drying trend in its climate. In response to these changing climatic conditions, as well as changes in farm commodity price relativities, farmers have adjusted their mix of enterprises to favour cereal production. As a result, an increasing potential source of cereal straw for bioenergy production has emerged. This paper examines how temporal and spatial costs of cereal straw accumulation may affect the establishment of a bioenergy plant in the region, with climate change impacts being highlighted. Logistics models based on mathematical programming are constructed for a range of plant sizes. Modelling results identify the cost structures of cereal straw accumulation for these plant sizes. Plant sizes are characterised by different cost structures and levels of volatility in their costs of grain accumulation. The profitability of bioenergy production based on cereal straw in this region of Australia is particularly exposed to climate variability, especially for larger plant sizes. The projected change in climate supports a relatively small reduction in the costs of cereal straw accumulation. These findings will affect decision-making over investment in a long-lived specific asset such as a bioenergy processing plant. [Copyright &y& Elsevier]

Abstract: China is one of the most important rice production countries in the world, and maintaining high rice productivity in China is very important for world food security. While previous studies showed that rice production in China has been and will be negatively impacted by global warming, the confounding effects of climatic change, variety improvement and agronomic managements have not been separately investigated. In this paper we combine an analysis of climate and rice growth data with crop modeling to investigate the impact of changes in climate, rice varieties, and agronomic management on rice productivity at four sites (Wuchang, Xinyang, Zhenjiang and Hanyuan) in China. The results showed a significant increase in minimum temperature during all rice growth stages at Wuchang and Zhenjiang, and from heading to maturity at Xinyang, but little change at Hanyuan. Global warming would have led to a reduction in the length of rice growing period and a reduction in grain yield at all study sites, if no varietal changes had occurred. However, the adoption of new rice varieties stabilized growing duration, increased harvest index and grain yield at three of the four sites. In the face of future warming, a planned breeding effort may be needed to offset the negative impact of future climate change. [Copyright &y& Elsevier]

This paper reviews the knowledge on effects of climate change on agricultural productivity in Europe and the consequences for policy and research. Warming is expected to lead to a northward expansion of suitable cropping areas and a reduction of the growing period of determinate crops (e.g. cereals), but an increase for indeterminate crops (e.g. root crops). Increasing atmospheric CO2 concentrations will directly enhance plant productivity and also increase resource use efficiencies.In northern areas climate change may produce positive effects on agriculture through introduction of new crop species and varieties, higher crop production and expansion of suitable areas for crop cultivation. Disadvantages may be an increase in the need for plant protection, the risk of nutrient leaching and the turnover of soil organic matter. In southern areas the disadvantages will predominate. The possible increase in water shortage and extreme weather events may cause lower harvestable yields, higher yield variability and a reduction in suitable areas for traditional crops. These effects may reinforce the current trends of intensification of agriculture in northern and western Europe and extensification in the Mediterranean and southeastern parts of Europe.Policy will have to support the adaptation of European agriculture to climate change by encouraging the flexibility of land use, crop production, farming systems etc. In doing so, it is necessary to consider the multifunctional role of agriculture, and to strike a variable balance between economic, environmental and social functions in different European regions. Policy will also need to be concerned with agricultural strategies to mitigate climate change through a reduction in emissions of methane and nitrous oxide, an increase in carbon sequestration in agricultural soils and the growing of energy crops to substitute fossil energy use. The policies to support adaptation and mitigation to climate change will need to be linked closely to the development of agri-environmental schemes in the European Union Common Agricultural Policy.Research will have further to deal with the effect on secondary factors of agricultural production, on the quality of crop and animal production, of changes in frequency of isolated and extreme weather events on agricultural production, and the interaction with the surrounding natural ecosystems. There is also a need to study combined effects of adaptation and mitigation strategies, and include assessments of the consequences on current efforts in agricultural policy to develop a sustainable agriculture that also preserves environmental and social values in the rural society. [Copyright &y& Elsevier]