Study On The Climate Change Impact On Chinese Oilseed Rape Production

Climate change issue is one of the biggest challenges facing the human society. According to the Fifth Assessment Report(AR5) published by Intergovernmental Panel on Climate Change(IPCC), many changes of climate observed since 1950 s imply the fact that the earth is getting warmer. An increasing number of studies have confirmed the impact that the past climate change had and the future climate change may have on the eco-system, the human society and welfare etc. The impact of climate change on agricultural production has been studied and confirmed as well. Most researches focused on rice, wheat, maize and soybean, while few studied oilseed crops. Oilseed rape(OSR) is the third most important source of vegetable oil and the second most important source of protein meal worldwide in 2015. The stability of OSR production is closely related to the livelihood of OSR farmers, the vegetable oil supply and global trade market of OSR. However, whether climate change has significant impact on OSR production is not certain. What impact that the past climate change might have on OSR producing input(e.g. pesticide and chemical fertilizer input), on OSR yield and sown area? What impact the projected climate change in the future may have on them?The paper aims to assess the impact of climate change on winter OSR yield, sown area and production. First of all, the relevant concepts are defined, then research results from relative literature are reviewed, and the research gap is pointed out. Secondly, the development of OSR industry in China and the world is introduced e.g. OSR yield, sown area and production. Based on that, we analyze the impact of past climate change on chemical fertilizer and pesticide input of OSR production from farmers’ level, identifying key climatic factors and key growth stages for OSR in terms of climate change impact. Thirdly, the impact of climate change on OSR yield is studied, and the key production regions, key climatic factors and key growth stages are identified in terms of climate change impact. Fourthly, the impact of climate change on OSR sown area is analyzed. Finally, we predict the impact of climate change on OSR yield, sown area and production in the mid-21 st century, and focus on the regional differences of climate change impact on OSR production in the future. Last but not the least, we summarize the climate change adaptation and mitigation policies from EU and the United States, then come up with policy suggestions to climate change adaptation and mitigation for Chinese OSR industry.The main conclusions are as follows:(1) The past climate change had negative impact on OSR yield in most regions. The past climate change had negative impact on OSR sown area in Southern China, Huanghuai Plain, the Middle Reaches of Yangtze River, and had positive impact on OSR yield in Yunnan-Guizhou Plateau, Sichuan Basin and the Lower Reaches of Yangtze River.(2) Future climate change will most likely have negative impact on OSR yield in Southern China, Sichuan Basin, the Lower Reaches of Yangtze River, and have positive impact on OSR yield in Huang-huai Plain, Yunnan-Guizhou Plateau, the Middle Rreaches of Yangtze River. Future climate change will most likely have negative impact on OSR sown area in Huang-huai Plain, the Middle Reaches of Yangtze River and positive impact on OSR sown area in Southern China, Yunnan-Guizhou Plateau, the Lower Reaches of Yangtze River and Sichuan Basin.(3) Future climate change will most likely cause OSR production reduction by 18300~26300 tons, which is roughly equivalent to OSR production of Southern China region in 2013.(4) We also found that the critical climatic factors for chemical fertilizer and pesticide input in terms of climate is temperature and precipitation respectively, especially at the seedling stage, the elongation and buds stage, and the flowering stage. Temperature has the biggest impact on OSR sown area in the majority of OSR production regions compared with other climate factors. Sunshine hours are critical for OSR at the mature stage.(5) OSR yield in lower latitude regions is more sensitive to warming and is more likely to reduce because of warming.(6) For non-climate factors, the most critical factor is labor input. It can be expected that labor input will become increasingly more important along with the economy development. OSR purchase policy had positive impact on OSR sown area growth.The possible novelty may be:(1) The paper tries to evaluate the impact of climate change on OSR production by analyze the impact of climate change on OSR yield and sown area respectively, then combine both impact. The previous studies tend to assume that climate change have no impact on crop sown area. However, the assumption may lead to imprecisely research results.(2) We try to analyze the spatial and temporal impact of climate change on OSR. The results show that OSR yield, sown area and production in some areas will increase, others will decrease due to climate change. Overall, the impact of climate change on different regions offset each other.(3) We divide growth period of OSR into four growth stages. Based on relevant theory and econometric methods, we analyze the impact of climatic variables of different growth stages on OSR input and yield.