Recent pause in the growth rate of atmospheric CO2 due to enhanced terrestrial carbon uptake

Terrestrial ecosystems play a significant role in the global carbon cycle and offset a large fraction of anthropogenic CO2 emissions. 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 CO2 on vegetation and the slowdown in the rate of warming on global respiration. The pause in the atmospheric CO2 growth rate provides further evidence of the roles of CO2 fertilization and warming-induced respiration, and highlights the need to protect both existing carbon stocks and regions, where the sink is growing rapidly. Corrigendum: An earlier publication by Leggett and Ball presented statistical evidence for a relationship between the pause in global temperature, a pause in the global rate of change of CO 2 and an increase in global vegetation cover. While this publication was initially omitted from the reference list of this Article, the authors acknowledge that given the overlap between the two studies and marked differences in their conclusions, citation of this earlier work is appropriate. Leggett, L. M. W. & Ball, D. A. Granger causality from changes in level of atmospheric CO 2 to global surface temperature and the El Nin˜o-Southern Oscillation, and a candidate mechanism in global photosynthesis. Atmos. Chem. Phys. 15, 11571–11592 (2015)