Climate change impacts on crop yield.pdf

Available online at /locate/pnsc Progress in Natural Science 19 (2009) 1665–1674Review Climate change impacts on crop yield, crop water productivity and food security – A review Yinhong Kang a, Shahbaz Khan b,*, Xiaoyi Ma a aDepartment of Water Resources and Architectural Engineering, Northwest AF University, Yangling 712100, China bDivision of Water Sciences, UNESCO, 1 Rue Miollis, 75 732 Paris Cedex 15, SP, France Received 20 May 2009; received in revised form 8 August 2009; accepted 14 August 2009Abstract This paper provides a comprehensive review of literature related to the assessment of climate change impacts on crop productivity using climate, water and crop yield models. The existing studies present that climate change models with higher spatial resolution can be a way forward for future climate projections. Meanwhile, stochastic projections of more than one climate model are necessary for providing insights into model uncertainties as well as to develop risk management strategies. It is projected that water availability will increase in some parts of the world, which will have its own effect on water use efficiency and water allocation. Crop production can increase if irrigated areas are expanded or irrigation is intensified, but these may increase the rate of environmental degradation. Since climate change impacts on soil water balance will lead to changes of soil evaporation and plant transpiration, consequently, the crop growth period may shorten in the future impacting on water productivity. Crop yields affected by climate change are projected to be different in various areas, in some areas crop yields will increase, and for other areas it will decrease depending on the latitude of the area and irrigation application. Existing modelling results show that an increase in precipitation will increase crop yield, and what is more, crop yield is more sensitive to the precipitation than temperature. If water availability is reduced in the future, soils of high