CLIMATE RESEARCH Clim Res Vol. 54: 233–247, 2012 doi: 10.3354/cr01131 Published online October 18 1. INTRODUCTION Annual anomalies of global land-surface air tem- perature, relative to the 1961-1990 mean, indicate a warming of 0.27°C per decade since 1979, with the greatest warming during winter (December to Febru- ary) and spring (March to May) in the Northern Hemi- sphere (IPCC 2007). Such changes have had mea- surable and spatially explicit effects on agricultural systems and crop production worldwide (e.g. Nicholls 1997, Peng et al. 2004, Tao et al. 2006, 2008, Piao et al. 2010, Lobell et al. 2011a,b). However, the effects of climate change are still not well understood (Lobell et al. 2011a), and some key unknowns and uncertainties hamper efforts to improve the prediction of crop pro- duction in the face of climate change (Tao et al. 2009). Our understanding of key unknowns and uncertain- ties of climate-change effects, and vulnerability and adaptation to this, can be advanced by studying data from the past few decades. Observed climate change and its effect on crop yields, at various spatial scales from local to global, has recently been studied by a number of authors (e.g. Nicholls 1997, Peng et al. 2004, Sheehy et al. 2006, Tao et al. 2006, 2008, Lobell & Field 2007, You et al. 2009, Li et al. 2010, Kristensen et al. 2011, Lobell et al. 2011a,b, Zhang & Huang 2012). These studies generally suggest that climate- yield relationships are scale-dependent. Improved datasets on climate and crop production, as well as novel approaches to analysis, are needed to better un- derstand the effects of climate on crop yields. In China for example, Tao et al. (2008) investigated climate-crop relationships, recent trends in seasonal climate, and the effects of these trends on major crop © Inter-Research 2012 · www.int-res.com *Email: taofl@igsnrr.ac.cn Response of crop yields to climate trends since 1980 in China Fulu Tao 1, *, Zhao Zhang 2 , Shuai Zhang 1,3 , Zhu Zhu 1 , Wenjiao Shi 1 1 Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, PR China 2 State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, PR China 3 Graduate University of Chinese Academy of Sciences, Beijing 100039, PR China ABSTRACT: We used improved datasets on both climate and crop production to investigate cli- mate trends during the crop growing period and their impacts on yields of major crops (rice, wheat, maize and soybean) in China by county, during 1980-2008. We found clear regional cli- mate trends during this period, particularly for temperature. Such trends have had measurable impacts on crop yields, with a distinct spatial pattern. For the entire country, the planting area- weighted average showed that climate trends from 1980-2008 reduced wheat, maize and soybean yields by 1.27, 1.73 and 0.41%, respectively, while increasing rice yields by 0.56%. As a result, cli- mate trends as a whole reduced wheat and maize production by 3.60 × 10 5 t and 1.53 × 10 6 t, respectively, and increased rice and soybean production by 7.44 × 10 4 t and 4.16 × 10 3 t, respec- tively. Estimates of climate impacts are smaller than previous estimates that used different scales, datasets and methods. The particular crops and regions that have been most affected and should be priorities for adaptation are maize and wheat in arid and semi-arid areas of northern and north- east China, where droughts induced by increases in temperature and solar radiation could limit the benefits of improved thermal conditions. Climate warming decreases crop yields by accelerat- ing crop development rate, and thus reducing crop growth duration and yield accumulation, and by increasing temperature extremes and heat stress. KEY WORDS: Climate change · Impacts and vulnerability · Sensitivity · Adaptation · Agriculture Resale or republication not permitted without written consent of the publisher This authors' personal copy may not be publicly or systematically copied or distributed, or posted on the Open Web, except with written permission of the copyright holder(s). It may be distributed to interested individuals on request.