Effects of climate variability and change on Chinese agriculture: a review

Evidence is reviewed from Chinese and international sources on the impacts of observed climate trends and extremes and of potential future climate change on agriculture. Recent climate behaviour in China shows progressive warming and complex patterns of precipitation variability and frequency of extreme events. Agricultural production data highlight substantial economic impacts from extreme climate events, with droughts causing the greatest effects on production. Observed warming has contributed to northward and northeastward expansion of winter wheat and maize cultivation, respectively. Multi-model climate change projections consistently predict warming throughout China and, with reasonable consistency, increases in precipitation across most of the country (averaging +5% to +7% by 2050, compared with 1961-1990). Studies of future climate change impacts on crops in China show a wide range of results, primarily due to differences among climate model projections, the methods used to assess crop impacts and whether the effects of CO2 fertilisation are included. Because of China's large size and range of agro-ecological conditions, sensitivity and exposure can vary considerably, leading to complex spatial patterns of response. Crop type and variety, and whether a crop is irrigated or rain-fed also affect yield. The review highlights research priorities, which include the need to systematically monitor, retrieve and analyse observed data on climate-yield behaviour, compare results of different modelling approaches and climate scenarios, and integrate climate effects within a broader framing of food systems.