The Detection of Global Climate Warming and Its Causes

The progress and advances in studies on the global climate warming are reviewed. The conclusions are as following: Earth surface temperature has increased by 0.5℃ during the last one hundred years. 1980’s became the warmest decade for that time interval. The warming is being in continuing in early 1990’s. 1990 was the warmest year, 1991 was the second warmer year since 1861. However, the warming of 0.5℃ is still in the range of natural variability. The temperatures in the Medieval Warm Period (900－1300) were probably comparable to that in the 20th century. The temperatures during the Little Ice Age (1550－1850) may be lower than that at present time by 1.0－1.5℃. Therefore, it is crucial to study systematically the impact of solar activity and volcanism on the climate for the last millennium. The warming in the warm scenario with doubled CO2 based on the time－dependent coupled GCM is 1.3－2.3℃, which is much less than the estimation of the balance simulation of AGCM. And, the cooling effect of the anthropogenic aerosol is emphasized, it could compensate partly the greenhouse effect.