TY - JOUR
T1 - Vegetation Greening and Climate Change Promote Multidecadal Rises of Global Land Evapotranspiration
AU - Zhang, Ke
AU - Kimball, John S.
AU - Nemani, Ramakrishna R.
AU - Running, Steven W.
AU - Hong, Yang
AU - Gourley, Jonathan J.
AU - Yu, Zhongbo
N1 - Funding Information:
This work was supported by the Disaster Relief Appropriations Act of 2013 (P.L. 113-2), which funded NOAA research grant NA14OAR4830100, the USGS South Central Climate Science Center at the University of Oklahoma through Grant #G13AC00386, the “Thousand Young Talents” Program in China, and grants (NNX15AB59G and NNX11AD46G) from the NASA Earth Science program.
PY - 2015/10/30
Y1 - 2015/10/30
N2 - Recent studies showed that anomalous dry conditions and limited moisture supply roughly between 1998 and 2008, especially in the Southern Hemisphere, led to reduced vegetation productivity and ceased growth in land evapotranspiration (ET). However, natural variability of Earths climate system can degrade capabilities for identifying climate trends. Here we produced a long-term (1982-2013) remote sensing based land ET record and investigated multidecadal changes in global ET and underlying causes. The ET record shows a significant upward global trend of 0.88 mm yr -'2 (P < 0.001) over the 32-year period, mainly driven by vegetation greening (0.018% per year; P < 0.001) and rising atmosphere moisture demand (0.75 mm yr -'2; P = 0.016). Our results indicate that reduced ET growth between 1998 and 2008 was an episodic phenomenon, with subsequent recovery of the ET growth rate after 2008. Terrestrial precipitation also shows a positive trend of 0.66 mm yr -'2 (P = 0.08) over the same period consistent with expected water cycle intensification, but this trend is lower than coincident increases in evaporative demand and ET, implying a possibility of cumulative water supply constraint to ET. Continuation of these trends will likely exacerbate regional drought-induced disturbances, especially during regional dry climate phases associated with strong El Niño events.
AB - Recent studies showed that anomalous dry conditions and limited moisture supply roughly between 1998 and 2008, especially in the Southern Hemisphere, led to reduced vegetation productivity and ceased growth in land evapotranspiration (ET). However, natural variability of Earths climate system can degrade capabilities for identifying climate trends. Here we produced a long-term (1982-2013) remote sensing based land ET record and investigated multidecadal changes in global ET and underlying causes. The ET record shows a significant upward global trend of 0.88 mm yr -'2 (P < 0.001) over the 32-year period, mainly driven by vegetation greening (0.018% per year; P < 0.001) and rising atmosphere moisture demand (0.75 mm yr -'2; P = 0.016). Our results indicate that reduced ET growth between 1998 and 2008 was an episodic phenomenon, with subsequent recovery of the ET growth rate after 2008. Terrestrial precipitation also shows a positive trend of 0.66 mm yr -'2 (P = 0.08) over the same period consistent with expected water cycle intensification, but this trend is lower than coincident increases in evaporative demand and ET, implying a possibility of cumulative water supply constraint to ET. Continuation of these trends will likely exacerbate regional drought-induced disturbances, especially during regional dry climate phases associated with strong El Niño events.
UR - http://www.scopus.com/inward/record.url?scp=84946127716&partnerID=8YFLogxK
U2 - 10.1038/srep15956
DO - 10.1038/srep15956
M3 - Article
C2 - 26514110
AN - SCOPUS:84946127716
SN - 2045-2322
VL - 5
JO - Scientific Reports
JF - Scientific Reports
M1 - 15956
ER -
