Hemispheric asymmetry in evapotranspiration reveals terrestrial water-flux redistribution
Global warming is widely expected to intensify the hydrological cycle. However, observational evidence for accelerated evapotranspiration (ET), a key terrestrial water cycle and energy balance component, remains ambiguous. Here, we constrained diverse datasets using basin-scale ET estimates covering 47% of global land to reveal a hidden asymmetry. We found a small global change in ET [−0.06 ± 0.44 mm year −2 (millimeters per year squared), P > 0.10] from 2000 to 2022, resulting from strongly opposing hemispheric trends. The Northern Hemisphere shows noticeable ET increases (0.91 ± 0.46 mm year −2 , P < 0.05), primarily driven by vegetation greening, whereas the Southern Hemisphere exhibits strong declines (−2.63 ± 0.46 mm year −2 , P < 0.05) due to precipitation deficits. Our observation-constrained projections indicate that this asymmetry is likely to persist through 2050. The small global ET trend masks a marked compensation between northern greening and southern drying, suggesting that current models may overestimate homogenized water cycle intensification. Our study provides profound implications for global food security, carbon sequestration, drought risks, and regional climate adaptation.
Authors
- Tim R. McVicar (ORCID: https://orcid.org/0000-0002-0877-8285)
- Zhipin Ai (ORCID: https://orcid.org/0000-0002-7991-3640)
- Xuanze Zhang (ORCID: https://orcid.org/0000-0001-8515-5084)
- Yongqiang Zhang (ORCID: https://orcid.org/0000-0002-3562-2323)
- Haoshan Wei (ORCID: https://orcid.org/0000-0002-2660-2371)
- Diego G. Miralles (ORCID: https://orcid.org/0000-0001-6186-5751)
- Zhenwu Xu (ORCID: https://orcid.org/0000-0003-2607-8343)
- S. Uhlenbrook (ORCID: https://orcid.org/0000-0002-3926-2599)
- Dongdong Kong (ORCID: https://orcid.org/0000-0003-1836-8172)
- Gang Zhao (ORCID: https://orcid.org/0000-0003-2737-0530)
- Yongyong Zhang (ORCID: https://orcid.org/0000-0001-9159-9626)
- Ning Ma (ORCID: https://orcid.org/0000-0003-4580-0661)
- Ronglin Tang (ORCID: https://orcid.org/0000-0001-6963-5010)
- Ge Sun (ORCID: https://orcid.org/0000-0002-0159-1370)
- X. Li (ORCID: https://orcid.org/0000-0002-9073-7799)
- Yuanyuan Huang (ORCID: https://orcid.org/0000-0003-4202-8071)
- Jing Tian (ORCID: https://orcid.org/0000-0002-7442-352X)
- Georgia Destouni
- Jun Xia
- Congcong Li (ORCID: https://orcid.org/0009-0008-1021-2329)
- Ronglin Tang
- Georgia Destouni
- Jun Xia
- Congcong Li (ORCID: https://orcid.org/0009-0008-1021-2329)
- Yongyong Zhang (ORCID: https://orcid.org/0000-0001-9159-9626)
Institutions
- Commonwealth Scientific and Industrial Research Organisation (AU)
- US Forest Service (US)
- Federal Office of Meteorology and Climatology MeteoSwiss (CH)
- Stockholm University (SE)
- Chinese Academy of Sciences (CN)
- Stellenbosch University (ZA)
- China University of Geosciences (CN)
- Ghent University (BE)
- Wuhan University (CN)
- Triangle (US)
- Institute of Geographic Sciences and Natural Resources Research (CN)
- KTH Royal Institute of Technology (SE)
Publication Details
- Journal
- Science Advances
- Published
- 2026-08-26
- DOI
- https://doi.org/10.1126/sciadv.aeg1633
- Primary Topic
- Plant Water Relations and Carbon Dynamics
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- Vetenskapsrådet