In this paper, firstly, the science background is simply summarized about the global climate change，then based on the compartmentalized time scale，the cau global climate warming. change and its effect factors in different time scales are discussed. By analyzed the key natural factors which could cause the climate change in different time scales and the anthropogenic influence upon climate change，it will be help for us to understand the present global climate warming. At the same time，the science diverging and perplexity on the study of climate change are also reviewed.