TY - JOUR
T1 - Recent decline in the global land evapotranspiration trend due to limited moisture supply
AU - Jung, Martin
AU - Reichstein, Markus
AU - Ciais, Philippe
AU - Seneviratne, Sonia I.
AU - Sheffield, Justin
AU - Goulden, Michael L.
AU - Bonan, Gordon
AU - Cescatti, Alessandro
AU - Chen, Jiquan
AU - De Jeu, Richard
AU - Dolman, A. Johannes
AU - Eugster, Werner
AU - Gerten, Dieter
AU - Gianelle, Damiano
AU - Gobron, Nadine
AU - Heinke, Jens
AU - Kimball, John
AU - Law, Beverly E.
AU - Montagnani, Leonardo
AU - Mu, Qiaozhen
AU - Mueller, Brigitte
AU - Oleson, Keith
AU - Papale, Dario
AU - Richardson, Andrew D.
AU - Roupsard, Olivier
AU - Running, Steve
AU - Tomelleri, Enrico
AU - Viovy, Nicolas
AU - Weber, Ulrich
AU - Williams, Christopher
AU - Wood, Eric F.
AU - Zaehle, Sönke
AU - Zhang, Ke
N1 - Funding Information:
Acknowledgements This work used eddy covariance data acquired by the FLUXNET community and in particular by the following networks: AmeriFlux (US Department of Energy, Biological and Environmental Research, Terrestrial Carbon Program; DE-FG02-04ER63917 and DE-FG02-04ER63911), AfriFlux, AsiaFlux, CarboAfrica, CarboEuropeIP, CarboItaly, CarboMont, ChinaFlux, Fluxnet-Canada (supported by the Canadian Foundation for Climate and Atmospheric Sciences, the Natural Sciences and Engineering Research Council of Canada, BIOCAP, Environment Canada and Natural Resources Canada), GreenGrass, KoFlux, the Largescale Biosphere–Atmosphere Experiment inAmazonia,theNordicCentrefor Studies ofEcosystemCarbonExchange, OzFlux, the Terrestrial Carbon Observatory System Siberia and US–China Carbon Consortium. We acknowledge the support to the eddy covariance data harmonization provided by CarboEuropeIP; the Food and Agriculture Organization of the United Nations’ Global Terrestrial Observing System Terrestrial Carbon Observations; the Integrated Land Ecosystem–Atmosphere Processes Study, a core project of the International Geosphere–Biosphere Programme; the Max Planck Institute for Biogeochemistry; the National Science Foundation; the University of Tuscia; Université Laval; Environment Canada; and the US Department of Energy. We acknowledge database development and technical support from Berkeley Water Center, Lawrence Berkeley National Laboratory, Microsoft Research eScience, Oak Ridge National Laboratory, University of California, Berkeley and University of Virginia. We thank the members of FLUXNET (http://www.fluxdata.org/DataInfo) for their help with the data on this work. TRMM soil moisture retrievals and analysis were supported by the European Union (FP6) funded integrated project called WATCH (contract number 036946)thatsupportedA.J.D.and R.d.J.M.J.andM.R. were supportedbythe European Union (FP7) integrated project COMBINE (number 226520) and a grant from the Max-Planck Society establishing the MPRG Biogeochemical Model-Data Integration. C.W. was supported by the US National Science Foundation under grant ATM-0910766. D.P. acknowledges the support of the Euro–Mediterranean Centre for Climate Change. We acknowledge institutions and projects for free access to relevant data: the Global Runoff Data Centre, the Global Soil Wetness Project 2, the Global Precipitation Climatology Centre, the Global Precipitation Climatology Project, the Global Historical Climatology Network, the Potsdam Institute for Climate Impact Research, the University of East Anglia, the National Oceanic and Atmospheric Administration Earth System Research Laboratory and the European Centre for Medium-Range Weather Forecasts.
PY - 2010/10/21
Y1 - 2010/10/21
N2 - More than half of the solar energy absorbed by land surfaces is currently used to evaporate water. Climate change is expected to intensify the hydrological cycle and to alter evapotranspiration, with implications for ecosystem services and feedback to regional and global climate. Evapotranspiration changes may already be under way, but direct observational constraints are lacking at the global scale. Until such evidence is available, changes in the water cycle on land-a key diagnostic criterion of the effects of climate change and variability-remain uncertain. Here we provide a data-driven estimate of global land evapotranspiration from 1982 to 2008, compiled using a global monitoring network, meteorological and remote-sensing observations, and a machine-learning algorithm. In addition, we have assessed evapotranspiration variations over the same time period using an ensemble of process-based land-surface models. Our results suggest that global annual evapotranspiration increased on average by 7.1 ± 1.0 millimetres per year per decade from 1982 to 1997. After that, coincident with the last major El Ni±o event in 1998, the global evapotranspiration increase seems to have ceased until 2008. This change was driven primarily by moisture limitation in the Southern Hemisphere, particularly Africa and Australia. In these regions, microwave satellite observations indicate that soil moisture decreased from 1998 to 2008. Hence, increasing soil-moisture limitations on evapotranspiration largely explain the recent decline of the global land-evapotranspiration trend. Whether the changing behaviour of evapotranspiration is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for earth system science.
AB - More than half of the solar energy absorbed by land surfaces is currently used to evaporate water. Climate change is expected to intensify the hydrological cycle and to alter evapotranspiration, with implications for ecosystem services and feedback to regional and global climate. Evapotranspiration changes may already be under way, but direct observational constraints are lacking at the global scale. Until such evidence is available, changes in the water cycle on land-a key diagnostic criterion of the effects of climate change and variability-remain uncertain. Here we provide a data-driven estimate of global land evapotranspiration from 1982 to 2008, compiled using a global monitoring network, meteorological and remote-sensing observations, and a machine-learning algorithm. In addition, we have assessed evapotranspiration variations over the same time period using an ensemble of process-based land-surface models. Our results suggest that global annual evapotranspiration increased on average by 7.1 ± 1.0 millimetres per year per decade from 1982 to 1997. After that, coincident with the last major El Ni±o event in 1998, the global evapotranspiration increase seems to have ceased until 2008. This change was driven primarily by moisture limitation in the Southern Hemisphere, particularly Africa and Australia. In these regions, microwave satellite observations indicate that soil moisture decreased from 1998 to 2008. Hence, increasing soil-moisture limitations on evapotranspiration largely explain the recent decline of the global land-evapotranspiration trend. Whether the changing behaviour of evapotranspiration is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for earth system science.
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U2 - 10.1038/nature09396
DO - 10.1038/nature09396
M3 - Article
C2 - 20935626
AN - SCOPUS:78049234152
SN - 0028-0836
VL - 467
SP - 951
EP - 954
JO - Nature
JF - Nature
IS - 7318
ER -