【摘要】 百年时间尺度全球和中国气候变暖存在不确定性,以中国为例,前50年观测资料不足可能造成百年变暖趋势的不确定性,后50年城市化进程热岛效应可能在增暖中占到25%。贡献于近50年中国气候的变暖,不仅来自人类排放增加,而且城市化,气温自然的准周期性和年代际变率,地面接收太阳辐射的减少(变暗)或增加(变明),以及其他外部强迫如火山活动和太阳活动与气候系统内部作用等。全球气候模式的不确定性和未来情景设计中的问题都将影响对变暖的原因分析,并使得10～20年预测的可信度较低。这些问题有待进一步研究解决。更多还原

【Abstract】 As mentioned in the IPCC report, the linear trend of the global annual mean surface air temperature during the last 100 years (1906 to 2005) is 0.74℃ (in the range of 0.56 to 0.92℃). The warming trend in China is 0.53～0.86℃ during the same period. But it should emphasized that there are some uncertainties and gaps in the information about the recent climate warming, especially in some special regions such as in China. The uncertainties of climate warming in China come from both lack of the observed data during the first half of the 20th century and the urbanization process (heat island effects) during the second half of the 20th century that might contribute 25% of the total warming. The climate warming in China during the last 50 years is not only contributed by the human activity, but also by the urbanization, the natural periodicity and decadal variability, dimming and brightening of the solar radiation, as well as other forcing factors such as solar activity, volcanic activity and interactions inside the climate system. The fractional uncertainties of the future climate prediction and projections vary due to internal variability of the global climate system, climate model uncertainty and scenario uncertainty. The global climate models do not have adequately fine resolutions due to the lack of high speed computers, with inveracious simulations by the models, especially in the regional scales. The parameterizations of the physical, chemical and biological processes in the global climate system are complicated. The present climate models can hardly describe those processes, interactions and the feedback mechanisms, such as clouds-aerosols-radiation feedbacks. The future climate changes will be caused by both natural and anthropogenic forcing factors. It is difficult to predict solar and volcanic activities in a long period. The human activities in future are provided as some scenarios, not the real human emissions. Therefore, the reliability of climate change prediction and predictions in China for the next decade will not be very high. More research should be conducted in future for narrowing the uncertainties.更多还原