With the 1880~2009 global temperature variations, this paper decomposes the temperature variations into the anthropogenic factors, which contributed by carbon emission from human activities, and the natural forcing, which is contributed by the natural oscillation of climate system. Results show that the anthropogenic forcing grows exponentially since 1860, while the natural forcing runs as a sine trend with a 60-year cycle which is composed by warm phase and cool phase. Therefore, though the anthropogenic forcing will work on a continuously temperature raise, the alternate cool phase of nature climate system will offset the warming trend indicating a temperature stabilization or even decrease. Further, due to the enhancement of exponential anthropogenic forcing on global temperature, the duration of temperature stabilization or decrease will become shorter one after another.