Quantifying the Impacts of Afforestation Induced Vegetation Changes on Surface Climate in Northern China

The three-north China region is one of the most environmental vulnerable regions. In late 1970s, Chinese government launched the Three-North Shelter Forest Programme, one of the largest afforestation programs in the world. It leads to the significant changes in vegetation. Although many studies have evaluated their impacts on local climate, the results were highly inconsistent. In this study, we investigated the evidence for the local climate impacts of vegetation change using remote sensing data and ground measurements from 1982 to 2006 by conducting the Granger causality test and lag correlation analysis. Results showed that the significant increase in vegetation had strong feedback on the precipitation, specific humidity, and wind speed, which have significant implications to this dry landscape. However, the feedbacks vary in different climate zones within the entire region and in different months.