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

Trevor F Keenan,G James Collatz,Michael Raupach,I Colin Prentice,Christopher A Williams,Josep G Canadell,Han Wang

doi:10.1038/ncomms13428

Trevor F Keenan, G James Collatz + Show 5 more

Open Access

PDF Available

https://doi.org/10.1038/ncomms13428

Copy DOI

Export

Save

Cite

Abstract
Highlights/Summary
Full-Text PDF
Similar Papers

Abstract

Listen

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.

Highlights

Terrestrial ecosystems play a significant role in the global carbon cycle and offset a large fraction of anthropogenic CO2 emissions
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
Our analysis suggests that enhanced carbon uptake is due to the combined effects of rising CO2 on photosynthesis and, in the past decade, a slowdown in the rate of warming on global respiration

Summary

Introduction

Terrestrial ecosystems play a significant role in the global carbon cycle and offset a large fraction of anthropogenic CO2 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. Global warming over vegetated land notably slowed since the start of the twenty-first century[23], while atmospheric CO2 concentrations continue to rise, providing an opportunity to test the relative roles of various processes in the enhancement of terrestrial carbon uptake, and examine the implications of enhanced carbon uptake for the growth rate of atmospheric CO2. The continued enhancement of the terrestrial carbon sink during the recent slowdown in global warming led to a pause in the atmospheric CO2 growth rate, and a decline in the fraction of anthropogenic emissions that remains in the atmosphere

Methods

Results

Conclusion