Disentangling climatic and anthropogenic controls on global terrestrial evapotranspiration trends Jiafu Mao1†, Wenting Fu2, Xiaoying Shi1, Daniel M. Ricciuto1, Joshua B. Fisher3, Robert E. Dickinson2, Yaxing Wei1, Willis Shem1, Shilong Piao4, Kaicun Wang5, Christopher R. Schwalm6,7, Hanqin Tian8, Mingquan Mu9, Altaf Arain10, Philippe Ciais11, Robert Cook1, Yongjiu Dai5, Daniel Hayes1, Forrest M. Hoffman12, Maoyi Huang13, Suo Huang10, Deborah N. Huntzinger7,14, Akihiko Ito15, Atul Jain16, Anthony W. King1, Huimin Lei17, Chaoqun Lu8, Anna M. Michalak18, Nicholas Parazoo3, Changhui Peng19, Shushi Peng11, Benjamin Poulter20, Kevin Schaefer21, Elchin Jafarov21, Peter E. Thornton1, Weile Wang22, Ning Zeng23, Zhenzhong Zeng4, Fang Zhao23, Qiuan Zhu19, and Zaichun Zhu24 1
Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA 2 Jackson School of Geosciences, the University of Texas, Austin, TX, USA 3 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA 4 Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China 5 College of Global Change and Earth System Science, Beijing Normal University, Beijing, China 6 Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ 86011, USA 7 School of Earth Sciences and Environmental Sustainability, Northern Arizona University, Flagstaff, AZ 86011, USA 8 International Center for Climate and Global Change Research and School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849, USA 9 Department of Earth System Science, University of California, Irvine, California, USA 10 School of Geography and Earth Sciences and McMaster Centre for Climate Change, McMaster University, Hamilton, Ontario, Canada 11 Laboratoire des Sciences du Climat et de l'Environnement, LSCE, 91191 Gif sur Yvette, France 12 Climate Change Science Institute and Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA 13 Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA 14 Department of Civil Engineering, Construction Management, and Environmental Engineering, Northern Arizona University, Flagstaff, AZ 86011, USA 15 National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan 16 Department of Atmospheric Sciences, University of Illinois, Urbana, IL 61801, USA 17 Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China 18 Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305, USA 19 Institute of Environmental Sciences, University of Quebec at Montreal (UQAM), Case postale 8888, succ Centre-Ville, Montréal, QC H3C 3P8, Canada 20 Department of Ecology, Montana State University, Bozeman, MT 59717, USA
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National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO 80309, USA 22 Ames Research Center, National Aeronautics and Space Administration, Moffett Field, Mountain View, CA 94035, USA 23 Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD 20742, USA 24 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100, China † Corresponding author: (Tel: +1-865-576-7815,
[email protected]) Keywords: evapotranspiration, natural and anthropogenic controls, factorial analysis, MsTMIP
This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC0500OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
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! Supporting Information Table S1. Trend statistics in ET median values for the observation-based estimates (DIA) and MsTMIP simulated results over different regions from 1982-2010. The DIA only has the ET trends, and MsTMIP simulations have the trends of ET, Tr and ET-Tr. The factorial results from the MsTMIP multi-model are ALL: the impact from all historical forcing factors, CLI: the impact from historical climate only, OTH: all the anthropogenic impact, CO2: the historical CO2 impact only, NDE: the historical nitrogen deposition impact only, LUC: the historical land use/land cover change impact only, Y: the availability of ET simulation for the particular impact, and N: the non-availability of ET simulation for the particular impact. Values in bold indicate statistically significant trend at the 90% level. Figure S1. Time series of annual anomalies of ET (mm yr−1) over (a) the globe, (b) the NH, and (c) the SH from 1982-2010. Solid lines are the median values of the merged ET from this study (ET_DIA, red), and the merged ET (Mueller, blue) from Mueller et al (2013). Shaded areas indicate the ±1 s.d. of ET_DIA for the overlapped period of the two datasets (1989-2005). Figure S2. Trends of global-, NH-, SH- and continental-scale ET (mm/yr-2) for DIA, ALL, CLI, OTH, CO2, NDE and LUC results. *P < 0.05 for the trend in ET median values being significantly different from zero. For each category of the model results, the color bar represents the trend in ET median values of the individual model. The error bars indicate the mean±1 s.d. of ET trend for individual model within each category. The pink colors represent the positive trends and the blue colors denote the negative changes. Figure S3. Spatial distribution of the linear trends in LAI (m-2/m-2/yr) for (a) CO2 result (LAI_CO2), and (b) NDE result (LAI_NDE) from 1982-2010. Figure S4. Spatial distribution of the linear trends in (a) ALL Tr (ALL_Tr), (b) ALL ETTr (ET-Tr_ALL), (d) CLI Tr (CLI_Tr), (e) CLI ET-Tr (ET-Tr_CLI), (g) OTH Tr (OTH_Tr), (h) OTH ET-Tr (ET-Tr_OTH), (j) CO2 Tr (CO2_Tr), (k) CO2 ET-Tr (ETTr_ CO2), (m) NDE Tr (NDE_Tr), (n) NDE ET-Tr (ET-Tr_NDE), (p) LUC Tr (LUC_Tr), and (q) LUC ET-Tr (ET-Tr_LUC). The unit of Tr and ET-Tr trend is mm/yr-2. (c), (f), (i), (l), (o) and (r) show the spatial distribution of the dominant component (Tr or ET-Tr) for the ET changes of each category. The insets show the frequency distribution of the corresponding change. Figure S5. Trends of global-, NH-, SH- and continental-scale ET, Tr and ET-Tr (mm/yr2 ). The results of ALL, CLI and OTH are associated with the left y axis, and those of CO2, NDE and LUC correspond to the right y axis. For each category of the model results, the color bar represents the trend in ET, Tr or ET-Tr median values of the individual model. The error bars indicate the mean±1 s.d. of ET, Tr or ET-Tr trend for individual model within each category. The pink colors represent the positive trends and the blue colors denote the negative changes.
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Figure S6. Trends of global-, NH- and SH- ET (mm/yr-2) for individual MsMTIP model. The results of ALL, CLI and OTH are associated with the left y axis, and those of CO2, NDE and LUC correspond to the right y axis.
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Regions
North America
South America
Europe
Africa
Asia
Australia
Global Land
Northern Hemisphere
Southern Hemisphere
ET and ET apartments
DIA
ALL
CLI
OTH
CO2
NDE
LUC
ET
1.332
0.528
0.682
0.003
-0.065
0.009
0.019
T
--
0.165
0.282
-0.113
-0.083
0.02
-0.032
ET-T
--
0.154
0.248
0.04
-0.007
-0.007
0.047
ET
2.056
1.297
1.372
-0.336
-0.289
0.062
0.005
T
--
0.971
0.753
-0.266
-0.286
0.13
-0.157
ET-T
--
1.364
1.966
-0.016
0.01
-0.003
-0.068
ET
1.378
0.789
0.649
0.01
-0.057
0.014
0.066
T
--
0.317
0.483
-0.074
-0.074
0.033
-0.134
ET-T
--
0.334
0.348
0.033
-0.014
-0.031
-0.005
ET
1.326
1.911
2.003
-0.039
-0.083
0.074
-0.045
T
--
1.496
1.032
0.018
-0.05
0.124
-0.037
ET-T
--
0.957
1.103
-0.004
-0.017
-0.022
-0.017
ET
0.564
0.372
0.475
-0.08
-0.086
0.018
-0.004
T
--
0.253
0.206
-0.077
-0.078
0.032
-0.044
ET-T
--
0.305
0.448
0.017
-0.016
-0.013
0.041
ET
0.861
1.261
1.2
0.061
-0.001
0.0004
0.0052
T
--
0.069
-0.011
0.013
0.022
0.018
-0.001
ET-T
--
0.744
0.71
-0.04
-0.029
-0.003
-0.053
ET
1.182
0.858
0.926
-0.127
-0.101
0.043
0.003
T
--
0.324
0.348
-0.067
-0.078
0.077
-0.099
ET-T
--
0.553
0.604
0.043
-0.005
-0.009
-0.035
ET
1.152
0.664
0.793
-0.144
-0.069
0.044
-0.008
T
--
0.222
0.454
-0.058
-0.062
0.037
-0.068
ET-T
--
0.418
0.444
0.025
-0.022
-0.013
-0.046
ET
1.233
1.168
1.218
-0.155
-0.165
0.042
-0.024
T
--
0.268
0.286
-0.097
-0.097
0.057
-0.17
ET-T
--
0.889
0.644
0.09
0.0003
-0.0004
-0.013
Table S1. Trend statistics in ET median values for the observation-based estimates (DIA) and MsTMIP simulated results over different regions from 1982-2010. The DIA only has the ET trends, and MsTMIP simulations have the trends of ET, Tr and ET-Tr. The factorial results from the MsTMIP multi-model are ALL: the impact from all historical forcing factors, CLI: the impact from historical climate only, OTH: all the anthropogenic impact, CO2: the historical CO2 impact only, NDE: the historical nitrogen deposition impact only, LUC: the historical land use/land cover change impact only, Y: the availability of ET simulation for the particular impact, and N: the non-availability of ET simulation for the particular impact. Values in bold indicate statistically significant trend at the 90% level.
figure s1
mm yr-1
(a)
ET_DIA Mueller
(b)
(c)
figure s2
Northern Hemisphere
Land
(b)
(a)
mm yr-2
(d)
OTH
CO2
NDE LUC
(f)
Asia
Australia
(h)
(g)
CLI
Europe
(e)
Africa
ALL
(c)
South America
North America
DIA
Southern Hemisphere
DIA
ALL
CLI
OTH
CO2
NDE LUC
(i)
DIA
ALL
CLI
OTH
CO2
NDE LUC
figure s3
figure s4
mm yr-2 mm yr-2
figure s5
Australia
UC U C _L _L -T -Tr ET ET C C LU LU T_ Tr_ UC UC _L _L ET ET D E DE _N N -Tr T-T_ ET E E ND E ND Tr_ T_ E DE _N T_ND ET E 2 2 O CO _C -Tr T-T_ E ET 2 CO O2 Tr_ T_C O2 2 _C CO ET T_ TH E H _O OT -Tr ET HT-T_ E H OT Tr_ T_OT TH H _O _OT ET E I LT I _C CL _ -Tr ET ET-T I CL CLI _ Tr_ T I LI _C T_CL ET E LL LL A _A -Tr -T_ ET ET L L AL AL Tr_ T_ LL _ALL _A ET ET
C LU -T_UC ET_L -Tr C ET LU T_ C LU C Tr_ T_LU E UC _L ET DNEDE r_-TN_ -TT ET E E N D DE N Tr_T_ E DE DN _NT_ ET E 2 OC2O r_-TC_ -TT ET E 2 2 C_OCO Tr_T 2 O 2 _C CO ET ET_ TH H _O OT -Tr -T_ ET ET H H OTOT Tr_T_ TH TH _O _O ET ET LI LI _C_C -TTr -T ET E I I CLCL _ Tr_T I LICL _CT_ ET E L LALL _TA_ -TTr ET E L LALL TA_ Tr_ LL L_LA _EAT ET
UC U_CL _TL-T -TrE ET C LU T_C LU C Tr_ LU UTC_ _LE ET DE E _ N ND -Tr -T_ ET ET E N D DE Tr_ T_N DE DE _N _N ET ET 2 2 O O _C _C -Tr -T ET ET 2 CO O2 Tr_ T_C O2 2 O _C ET ET_C TH _O OTH _ -Tr ET ETH-T OT TH Tr_ T_O TH H _O OT ET ETL_I I _ C CL -Tr T_ ET ETI CL CLI Tr_ T_ LI LI _C _C ET ET L L L L _ A _A -Tr -T ET ET L L AL_AL Tr_ T L LL AL _A T_ ET E
Africa
(i)
Asia (h) (g)
Europe (f)
South America (e)
North America
Southern Hemisphere Northern Hemisphere Land
(c) (b) (a)
(d)
figure s6 mm yr-2
mm yr-2 (a)
Northern Hemisphere
(b)
Land
Southern Hemisphere
(c)
ET
ALL
CLI
OTH
NDE
CO2
LUC
ALL
CLI
OTH
CO2
NDE
ALL
LUC
CLI
OTH
CO2
NDE
LUC
IT
VIS
A
AS
S GA VE
C SIB
+
CE
-LS
PL
EE
3-J
HID
sl -w
SIB
C OR
J LP
EC GT
HG -G
X LE
M
IP TR
ISA
EM DL
M4 CL
C -VI
-N
EM CT
S-
M4 CL
AS CL
C -BG
ME BIO
