Recent pause in the growth rate of atmospheric CO2due to enhanced terrestrial carbon uptake.
Terrestrial ecosystems play a significant role in the global carbon cycle and offset a large fraction of anthropogenic CO2emissions. The terrestrial carbon sink is increasing, yet the mechanisms responsible for its enhancement, and implications for the growth rate of atmospheric CO2, remain unclear. Here using global carbon budget estimates, ground, atmospheric and satellite observations, and multiple global vegetation models, we report a recent pause in the growth rate of atmospheric CO2, and a decline in the fraction of anthropogenic emissions that remain in the atmosphere, despite increasing anthropogenic emissions. We attribute the observed decline to increases in the terrestrial sink during the past decade, associated with the effects of rising atmospheric CO2on vegetation and the slowdown in the rate of warming on global respiration. The pause in the atmospheric CO2growth rate provides further evidence of the roles of CO2fertilization and warming-induced respiration, and highlights the need to protect both existing carbon stocks and regions, where the sink is growing rapidly.
Earth Sciences Division, Lawrence Berkeley National Lab, Berkeley, California 94709, USA.|Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia.
Trevor F
0000-0002-3347-0258
TF
Keenan
Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia.|Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot SL5 7PY, UK.
I Colin
IC
Prentice
Global Carbon Project, CSIRO Oceans and Atmosphere, Canberra, Australian Capital Territory 2601, Australia.
Josep G
JG
Canadell
Department of Biology, Graduate School of Geography, Clark University, Worcester, Massachusetts 01610, USA.
Christopher A
CA
Williams
Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia.|State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Forestry, Northwest A &F University, Yangling 712100, China.
Han
0000-0003-2482-1818
H
Wang
Global Carbon Project, CSIRO Oceans and Atmosphere, Canberra, Australian Capital Territory 2601, Australia.
Michael
M
Raupach
Biospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA.
G James
GJ
Collatz