Greening-induced increase in evapotranspiration over Eurasia offset by CO 2 -induced vegetational stomatal closure

Bibliographic Data

ID15549355
AuthorsXuanze Zhang (0000-0001-8515-5084, Institute of Geographic Sciences and Natural Resources Research, corresponding author), Yongqiang Zhang (0000-0002-4192-5961, Chinese Academy of Sciences, corresponding author), Ning Ma (0000-0002-9503-3192, Chinese Academy of Sciences), Dongdong Kong (0000-0003-1836-8172, China University of Geosciences), Jing Tian (0000-0001-7746-7782, Chinese Academy of Sciences), Xingmin Shao (Institute of Geographic Sciences and Natural Resources Research), Qiuhong Tang (0000-0002-0886-6699, Chinese Academy of Sciences)
Year2021
Volume16
Issue12
Pages124008-124008
Publication date2021-11-01
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueEnvironmental Research Letters (JOURNAL)
Journal identifiersISSN: 1748-9326 • E-ISSN: 1748-9326
PublisherIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/ac3532
OpenAlexW3210501251
LanguageEN
Citations received4
References cited61

Evapotranspiration (ET), as a key exchanging component of the land energy, water and carbon cycles, is expected to increase in response to greening land under a warming climate. However, the relative importance of major drivers (e.g. leaf area index (LAI), climate forcing, atmospheric CO 2 , etc) to long-term ET change remain largely unclear. Focusing on the Eurasia which experienced the strong vegetational greening, we aim to estimate the long-term ET trend and its drivers’ relative contributions by applying a remote sensing-based water-carbon coupling model— Penman–Monteith–Leuning version 2 (PML-V2) driven by observational climate forcing and CO 2 records, and satellite-based LAI, albedo and emissivity. The PML-V2 estimated an increasing ET trend (6.20 ± 1.13 mm year −1 decade −1 , p < 0.01) over Eurasia during 1982–2014, which is close to the ensemble mean (6.51 ± 3.10 mm year −1 decade −1 ) from other three ET products (GLEAMv3.3a, ERA5 and CRv1.0). The PML-based ET overall agrees well with water-balance derived ET in detecting the trend directions. We find that the Eurasian ET increasing trend was mostly from vegetated regions over central and eastern Europe, Indian and southeast China where ET trends were larger than 20 mm year −1 decade −1 . Modeling sensitivity experiments indicate that the Eurasian ET trend was mainly dominated by positive contributions from climate forcing change (40%) and increased LAI (22%), but largely offset by a negative contribution of increased CO 2 (26%). Our results highlight the importance of the suppression effect of increasing CO 2 -induced stomatal closure on transpiration. This effect was rarely considered in diagnostic ET products but plays a key role to ensure that the long-term ET trend should not be overestimated by only accounting for greening-induced increases in transpiration and rainfall interception

Albedo (alchemy · Atmospheric sciences · Climate change · Climatology · Evapotranspiration · Forcing (mathematics · Geography · Greenhouse gas · Greening · Leaf area index · Physical geography · Radiative forcing · Climate variability and models · Environmental Science · Hydrology and Watershed Management Studies · Plant Water Relations and Carbon Dynamics · Ecology · Geology

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