Abstract: A large number of evidence obtained from instrumental and geologic data support the conclusion that temperature has been rising for recent 150 years. By comparing the temporal variations between climate change and insolation variation at different time scales, the results showed that climate change on the earth was controlled by variation of the solar radiation. According to the estimated solar radiation derived from the earth orbit parameters, the insolation would be decreased from present time to the future 10ka years, thus indicating that the climate will shift to cold gradually. In the past 150 years, the temperature rising has been interpreted in two factors, one was human anthropogenic activity and the other is nature forcing. IPCC pointed to the fact that the human activity exerted the dominant influence on recent warming. IPCC overstated the anthropogenic effct on the global warming. Seen from a longer time scale, the recent 150 years warming is transient, which can be considered as a subprime fluctuation under the background of future colder trend.