中文摘要：

政府间气候变化专门委员会（IPCC）第一工作组于2007年2月2日发布的第四次评估报告明确指出，近100a（1906—2005年）地球表面平均温度上升了0．74℃，近50a的线性增温速率为0．13℃／10a，1850年以来最暖的12个年份中有11个出现在近期的1995—2006年。全球变暖已经是不争的科学事实，报告认为人类活动是近50a全球气候系统变暖的主要原因。IPCC评估报告是国际科学界对气候变化问题最权威、最全面的认识，代表了目前全球气候变化研究的科学认识水平，是国际上制定相关政策的重要依据。

英文摘要：

＂Climate Change 2007： The Physical Science Basis＂, the Working Group I contribution to the IPCC Fourth Assessment Report （AR4） was launched on February 2, 2007. The report clearly indicates that the updated 100-year （1906-2005） linear trend of global surface temperature is 0.74℃. The linear warming trend over the last 50 years is 0.1 3℃ per decade. Eleven of the last twelve years （1995-2006） rank among the 12 warmest years since 1850. Warming of the climate system is unequivocal. The report also indicates that most of the observed warming of the climate system over the last 50 years is very likely due to human activities. IPCC assessment reports summarize peer-reviewed and comprehensive findings from international scientific communities, represent the current level of scientific understanding of global climate change research, and provide an important basis for international climate regime and relevant national policies.