Elevated CO 2 mitigated warming-enhanced carbon loss from northern peatland
Peatlands store one-third of the global soil carbon (C) on only ∼3% of Earth’s land surface but risk becoming C sources to accelerate climate change due to warming-induced C loss. Elevated CO 2 (eCO 2 ) may mitigate this loss by boosting plant C uptake. However, how eCO 2 and climate warming interact to influence peatland C dynamics remains unclear. Here, we investigated peatland C fate at five warming levels (+0°, +2.25°, +4.5°, +6.75°, and + 9°C), each under ambient CO 2 (aCO 2 ) and eCO 2 (+500 parts per million), by model-guided synthesis of 18 measured variables for each of the 10 treatments from an experiment. Our results showed that the peatland C loss increased with warming at a rate of 62.6 g C m −2 year −1 °C −1 , reaching 476.5 ± 104.7 g C m −2 year −1 at +9°C under aCO 2 , primarily because of increased Sphagnum mortality and accelerated decomposition. eCO 2 reduced the loss rate to 17.3 g C m −2 year −1 °C −1 , nearly halving the C loss at +9°C (269.4 ± 80.5 g C m −2 year −1 ), mainly due to enhanced tree and shrub growth. Methane emissions increased with warming, similarly under aCO 2 and eCO 2 . Our findings suggest that northern peatlands likely become major C sources under climate warming, although rising atmospheric CO 2 concentration may partially slow down the C loss. Climate-driven shifts in plant community structure, rather than peat decomposition alone, play a critical role in regulating peatland C fate and may threaten the stability of peatland ecosystem functions and services in the future.
Authors
- Mirindi Eric Dusenge (ORCID: https://orcid.org/0000-0003-4218-0911)
- Mara Y. McPartland (ORCID: https://orcid.org/0000-0002-1242-0438)
- Jeffrey M. Warren (ORCID: https://orcid.org/0000-0002-0680-4697)
- Verity Gale Salmon (ORCID: https://orcid.org/0000-0002-2188-551X)
- Feng Tao (ORCID: https://orcid.org/0000-0001-6105-860X)
- Natalie A. Griffiths (ORCID: https://orcid.org/0000-0003-0068-7714)
- Weinan Chen (ORCID: https://orcid.org/0000-0003-0227-4454)
- Melanie A. Mayes (ORCID: https://orcid.org/0000-0001-6368-9210)
- Paul J. Hanson (ORCID: https://orcid.org/0000-0001-7293-3561)
- Sören Eliot Weber (ORCID: https://orcid.org/0000-0002-6351-5365)
- Lifen Jiang (ORCID: https://orcid.org/0000-0002-1546-8189)
- Yiqi Luo (ORCID: https://orcid.org/0000-0002-4556-0218)
- Yu Zhou (ORCID: https://orcid.org/0000-0002-5544-8342)
- Richard J. Norby (ORCID: https://orcid.org/0000-0002-0238-9828)
- Jian Zhou (ORCID: https://orcid.org/0000-0001-9276-6086)
- Danielle A. Way (ORCID: https://orcid.org/0000-0003-4801-5319)
- Yahai Zhang (ORCID: https://orcid.org/0000-0001-9134-0964)
- Daniel M. Ricciuto (ORCID: https://orcid.org/0000-0002-3668-3021)
- Wenjuan Huang (ORCID: https://orcid.org/0000-0003-1038-1591)
- Quan Quan (ORCID: https://orcid.org/0000-0002-8202-6858)
- Haodi Xu (ORCID: https://orcid.org/0000-0003-3839-7202)
- Xiaoying Shi
Institutions
- Australian National University (AU)
- West Virginia University (US)
- Western University (CA)
- Oak Ridge National Laboratory (US)
- Pennsylvania State University (US)
- Duke University (US)
- Iowa State University (US)
- Cornell University (US)
- ETH Zurich (CH)
- University of Tennessee at Knoxville (US)
- Leipzig University (DE)
Publication Details
- Journal
- Science Advances
- Published
- 2026-10-30
- DOI
- https://doi.org/10.1126/sciadv.aek1491
- Primary Topic
- Peatlands and Wetlands Ecology
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- U.S. Department of Energy
- U.S. Department of Agriculture