Dams not to blame for all reservoir carbon emissions from retained organic carbon
Dams trap organic carbon (OC) and create carbon dioxide (CO 2 ) and methane (CH 4 ) emission hotspots within reservoirs, underlying the ongoing debate over their role in carbon emissions. However, even without dams, this labile OC would still decompose and emit CO 2 or CH 4 during downstream transport and after deposition in estuaries. Thus, relying solely on dammed reservoir observations to assess these emissions may introduce considerable bias. Here, we simulated both dammed and non-dammed scenarios for 5346 global reservoir dams to assess their impact on carbon emissions from retained OC. The results show that reservoir-only approaches overestimate dam-induced carbon emissions by neglecting baseline emissions under no-dam conditions. After baseline correction, dams increase carbon emissions by an average of 21.5% in CO 2 -equivalent (CO 2 -eq), which represents only 18.6% of the emissions estimated using the conventional reservoir-based accounting approach. XGBoost identified reservoir depth and hydraulic residence time as the primary controls on dam-induced carbon emissions.
Authors
- Xiangyu Min (ORCID: https://orcid.org/0000-0001-8860-0163)
- Kun� Shi (ORCID: https://orcid.org/0000-0002-6124-7512)
- Qingji Zhang (ORCID: https://orcid.org/0000-0002-9426-7157)
- Wenqing Shi (ORCID: https://orcid.org/0009-0004-4382-5296)
- Boqiang Qin (ORCID: https://orcid.org/0000-0003-3977-4903)
- Hans W. Paerl (ORCID: https://orcid.org/0000-0003-2211-1011)
- Erik Jeppesen (ORCID: https://orcid.org/0000-0002-0542-369X)
- Ziqian Li
- Lin Zhu
Institutions
- University of North Carolina at Chapel Hill (US)
- Yunnan University (CN)
- Chinese Academy of Sciences (CN)
- Nanjing University of Information Science and Technology (CN)
- Aarhus University (DK)
- Institute of Agricultural Resources and Regional Planning (CN)
- Sino-Danish Centre for Education and Research (CN)
- Nanjing Institute of Geography and Limnology (CN)
- Chinese Academy of Agricultural Sciences (CN)
- State Key Laboratory of Lake Science and Environment (CN)
- Aarhus University Centre for Water Technology (DK)
Publication Details
- Journal
- Science Advances
- Published
- 2026-10-28
- DOI
- https://doi.org/10.1126/sciadv.aeg7676
- Primary Topic
- Atmospheric and Environmental Gas Dynamics
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- National Natural Science Foundation of China
- Chinese Academy of Sciences
- Government of Jiangsu Province
- Natural Science Foundation of Jiangsu Province
- Nanjing University
- National Institutes of Health
- U.S. Geological Survey
- Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences
- National Key Research and Development Program of China