Impact of Earth Greening on the Terrestrial Water Cycle

• DOI: 10.1175/jcli-d-17-0236.1
• Publication Date: 2018-01-11T20:50:32Z
• Authors: Zhenzhong Zeng; Shilong Piao; Laurent Z. X. Li; Tao Wang; Philippe Ciais; Xu Lian; Yuting Yang; Jiafu Mao; Xiaoying Shi; Ranga B. Myneni
• Keywords: Water cycle; Permanent wilting point

Leaf area index (LAI) is increasing throughout the globe, implying Earth greening. Global modeling studies support this contention, yet satellite observations and model simulations have never been directly compared. Here, for first time, a coupled land–climate was used to quantify potential impact of satellite-observed greening over past 30 years on terrestrial water cycle. The global LAI enhancement 8% between early 1980s 2010s modeled caused increases 12.0 ± 2.4 mm yr −1 in evapotranspiration 12.1 2.7 precipitation—about 55% 25% 28% 6% observed land precipitation, respectively. In wet regions, did not significantly decrease runoff soil moisture because it intensified recycling through coincident increase precipitation. But dry including Sahel, west Asia, northern India, western United States, Mediterranean coast, its coupling with atmospheric This response, however, might biases resulting from precipitation model. For example, bias underestimated response (e.g., Sahel India) given that near wilting point. Thus, an accurate representation feedbacks system models essential predictions how responds changes, therefore cycle climate change.