IPCC-AR4模式对中国21世纪气候变化的情景预估

Projection of climate change in China in the 21st century by IPCC-AR4 Models

利用政府间气候变化委员会(IPCC)第四次评估报告提供的13个新一代气候系统模式的模拟结果,分析了不同情景下(高排放SRESA2、中等排放A1B、低排放B1)中国区域未来100年的气候变化。结果表明,21世纪中国气候预估显著变暖、变湿,世纪末变暖范围在1.6℃～5℃之间,年降水量增加1.5%～20%。在A2、A1B和B1情景下,21世纪末期增暖幅度依次为5.3℃、4.3℃和2.8℃,平均3.5℃,年降水量预估增加依次为11%、9.6%和6.4%,平均达7.5%。气温和降水变化的地理分布显示:北方增温幅度大于南方,降水的增加也主要集中在北方。冬季变暖最明显,降水则在冬、春季增加较显著。模式预估结果的不确定性分析表明,新一代全球系统模式对21世纪中国气候变化预估的可靠性得到了提高。

Using the outputs as simulated by 13 GCM models provided by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change （IPCC-AR4）, the situation of climate change in China in the future 100 years under SRES A2, A1B and B1 greenhouse gas is analyzed. We analyzed linear tendency, time series and annual changes of temperature and precipitation in all scenarios. The results show that the climate in China has a warming and wetting tendency in the 21st century. The range of temperature changes is from 1.6℃-5℃, the mean warming is 3.5℃, and precipitation is from 1.5%-20% with a mean of 7.5%. Considering the effect of SRES A2, A1B and B1, the temperature in China would be increased by 5.3℃, 4.3℃ and 2.8℃ respectively at the end of the 21st century. The precipitation would be increased by 11%, 9.6% and 6.4% at the end of 21st century. The largest range of warming is in winter, while the increase of precipitation is larger in winter and spring. The distributions of the mean temperature and precipitation in China were analyzed in this paper. The results indicated that the distributions of temperature are almost similar in all the scenarios, the warming over the northern part is greater than that in the southern part of China, but the warmest scenario is A2. The warmest area is in plateau, the second is near northeast and northwest of China, the other areas will increase from southeast to northwest gradually. And the distributions of precipitation are almost similar in all the scenarios too. The distribution of increased precipitation in China is also in the northern part of China. Precipitation increases obviously in North, Northwest and Northeast China, and increase in the region south of the Yangtze River. Compared with results of Third Assessment Report of the Intergovernmental Panel on Climate Change （IPCC-TAR）, differences among models supplied by IPCC-AR4 have been obviously reduced. The ensemble standard deviation of different models suggests that the uncertainty of the projected climate changes over China in the 21st century has been improved. But the resolution of GCM is still low currently, we could consider other methods, such as downscaling （dynamic or statistic）, then estimate area climate changes in the future.