中文摘要：

基于政府间气候变化委员会第四次评估报告（IPCC-AR4）所采用的20个气候模式在未来大气温室气体中等排放情景（A1B）下模拟结果的集合平均以及一个全球气候模式模拟输出驱动下的动力降尺度（downscaling）分析结果,对青藏高原地区未来30~50年的气候变化趋势进行了预估研究。结果表明,从2030—2049年相对于1980—1999年气候平均值的变化来看,青藏高原大部分地区年平均地面气温的升温幅度在1.4~2.2℃之间,高海拔地区的增温一般更为显著,西藏西部的冬季增暖将达到2.4℃以上。降水量的变化相对较小,青藏高原大部分地区和全年多数季节降水可能增加,但未来30~50年青藏高原地区降水率增量通常不超过5%。考虑到未来大气温室气体排放程度、多模式集合预估以及区域尺度气候模拟等多方面均可能存在不确定性,这里给出的青藏高原未来气候变化预估结果应适时检验和修正。

英文摘要：

Based on the ensemble average of outputs under the mid-range emission （A1B） scenario from 20 climate models used by the Intergovernmental Panel on Climate Change Fourth Assessment Report （IPCC-AR4）, and dynamically downscaling results driven by modeling outputs from a global climate model, climate change over the Tibetan Plateau in the next 30-50 years has been studied. The results show that annual-mean surface air temperature would rise by 1.4-2.2℃ averaged for 2030-2049 in most portions of the Plateau with respect to that for 1980--1999. Climatic warming is more prominent in higher-elevation regions and in colder seasons. For example, the temperature would increase up to 2.4℃ or more in Xizang autonomous region in winter. The change in precipitation would be relatively small and generally below 5 %, though the precipitation likely increases in main parts of the Plateau and in most seasons. Considering of various uncertainties in future emission of atmospheric greenhouse gases, skill of multi-model ensemble projection and regional-scale modeling, timing reexamination and correction will be needed when the above projections turn to practical applications.