两种气候变化情景下中国未来的粮食供给

全球温室气体排放导致的全球温度的上升一直是国际社会关注的重点问题之一。利用IPCC（政府间气候变化专门委员会）SRES（排放情景特别报告）的A2（中-高）和B2（中-低）温室气体排放情景，结合区域气候模式PRECIS和CERES作物模型模拟和分析了未来不同的温室气体排放情景下，中国未来2020年、2050年和2080年各个时段粮食的供需情景，并结合未来社会经济的发展分析了气候变化对未来粮食供求的影响，探讨了不同的气候变化程度对未来中国粮食供应的影响。结果表明：如果不考虑CO2的肥效作用，未来我国三种主要粮食作物（小麦、水稻和玉米）均以减产为主，灌溉可以部分地减少减产幅度，如果单考虑CO2的肥效作用，三种作物的产量变化以增产为主。若保持959／6的粮食自给率，人口按照SRESA2和B2情景增长，到2030年的技术进步可使粮食年单产递增0．79／6以上，维持目前的种植比例和种植面积，B2情景下，气候变化对我国的粮食安全问题将不会构成威胁，而A2情景下，气候变化将会对我国可持续发展的粮食安全造成威胁。

The Food Security of China under IPCC SRES A2 and B2 Scenarios

The temperature increase due to the greenhouse gases emission is the hot topic of international community. By using the IPCC SRES A2 and B2 greenhouse gases emission scenarios, regional climate model- PRECIS and crop model- CERES, combined with the social economical scenarios downscaled from the IPCC SRES, the grain supply and demand in 2020, 2050 and 2080 were simulated and analyzed. The Results show that the three main food plants yields would decrease under both A2 and 132 scenarios without considering the CO2 direct effect, the range of yield descent would reduce if there is enough irrigation. Yield could increase yet if the CO2 direct effect was included in the simulation. With the assumption of a 5% grain import percentage, a population increase scenario described by SRES A2 or B2, technology advance will make grain yield increase above 0.7% fro or 1% by 2030. With the same percentage of plants and planting areas as present, food supply would meet the demand under B2 scenarios, while would not under A2 scenarios.