Impact of recent vegetation greening on temperature and precipitation over China

摘要

Changes in land-use management and natural climate variability has led to significant vegetation greening in China over the past decades, as evidenced by satellite observations. In this study, we used a high-resolution land-atmosphere coupled regional climate model to assess the impacts of recent greening on China's regional summer climate. Our results inferred a country-averged surface cooling of 0.11 degrees C and a precipitation increase of 0.02 mm/d during summer in response to China's widespread greening. We also identified significant regional variability in the climatic responses to vegetation change. The regions of northern China showed significant cooling, including the Northeast China Plain, Loess Plateau, and the eastern areas of the Northern arid and semiarid region; however, no significant temperature changes were simulated in southern China. Summer precipitation decreased in southern China and increased in the Huang-Huai-Hai Plain and the northern Loess Plateau. Variations in moisture flux convergence had a stronger influence on the precipitation patterns relative to evapotranspiration. Furthermore, our results suggested that vegetation greening would influence the occurrence of extreme climate events by decreasing the number of heatwave days (by 1-3 days, particularly in northern China), reducing the number of continuous drought events in northern China, and minimizing the risks of floods in southern China.