Attribution of global soil moisture drying to human activities: a
quantitative viewpoint
Xihui Gu1, 5, 9, Qiang Zhang2, 3, 4, Jianfeng Li5, Vijay P. Singh6, Jianyu Liu7,
Peng Sun8, Changxiu Cheng2, 3, 4
Department of Atmospheric Science, School of Environmental Studies, China University of Geosciences, Wuhan 430074, China;
Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China;
Faculty of Geographical Science, Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China;
State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China;
Department of Geography, Hong Kong Baptist University, Hong Kong, China;
Department of Biological and Agricultural Engineering and Zachry Department of Civil Engineering, Texas A&M University, College Station, Texas, USA;
Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China;
College of Territorial Resources and Tourism, Anhui Normal University, Anhui 241000, China;
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS.
Abstract: Anthropogenic impacts on widespread global soil moisture (SM) drying in the root zone layer during 1948-2005 were evaluated based on the Global Land Data Assimilation System version 2 (GLDAS-2) and Global Climate Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) using trend analysis and optimal fingerprint methods. Both methods show agreement that natural forcing alone cannot drive significant SM drying. There is a high probability (≥90%) that the anthropogenic climate change signal is detectable in global SM drying. Specifically, anthropogenic greenhouse gas forcing can lead to global SM drying by 2.1×10-3 m3/m3, which is comparable to the drying trend seen in GLDAS-2 (2.4×10-3 m3/m3) over the past 58 years. Global SM drying is expected to continue in the future, given continuous greenhouse gas emissions.
Published in Geophysical Research Letters, 2019, doi: 10.1029/2018GL080768
