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This content will become publicly available on September 12, 2026

Title: The weak land carbon sink hypothesis
Over the past three decades, assessments of the contemporary global carbon budget consistently report a strong net land carbon sink. Here, we review evidence supporting this paradigm and quantify the differences in global and Northern Hemisphere estimates of the net land sink derived from atmospheric inversion and satellite-derived vegetation biomass time series. Our analysis, combined with additional synthesis, supports a hypothesis that the net land sink is substantially weaker than commonly reported. At a global scale, our estimate of the net land carbon sink is 0.8 ± 0.7 petagrams of carbon per year from 2000 through 2019, nearly a factor of two lower than the Global Carbon Project estimate. With concurrent adjustments to ocean (+8%) and fossil fuel (−6%) fluxes, we develop a budget that partially reconciles key constraints provided by vegetation carbon, the north-south CO2gradient, and O2trends. We further outline potential modifications to models to improve agreement with a weaker land sink and describe several approaches for testing the hypothesis.  more » « less
Award ID(s):
2425932 2003205
PAR ID:
10636008
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Corporate Creator(s):
Editor(s):
NA
Publisher / Repository:
The American Association for the Advancement of Science
Date Published:
Journal Name:
Science Advances
Edition / Version:
1
Volume:
11
Issue:
37
ISSN:
2375-2548
Page Range / eLocation ID:
eadr5489
Subject(s) / Keyword(s):
global carbon cycle budget, terrestrial carbon sink, fossil fuel emissions, vegetation biomass, remote sensing
Format(s):
Medium: X Size: 1.32 MB Other: pdf
Size(s):
1.32 MB
Sponsoring Org:
National Science Foundation
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