Land availability and policy commitments limit global climate mitigation from forestation
Forestation (afforestation and reforestation) could mitigate climate change by sequestering carbon within biomass and soils. However, global mitigation from forestation remains uncertain owing to varying estimates of carbon sequestration rates (notably in soil) and land availability. In this study, we developed global maps of soil carbon change that reveal carbon gains and losses with forestation, primarily in the topsoil. Constraining land availability to avoid unintended albedo-induced warming and safeguard water and biodiversity (389 million hectares available for forestation globally) would sequester 39.9 petagrams of carbon by 2050, substantially below previous estimates. This estimate drops to 12.5 petagrams of carbon with land further limited to existing policy commitments (120 million hectares). Achieving greater mitigation requires expanding dedicated forestation areas and strengthening commitments from nations with considerable but untapped potential.
Authors
- Wen Zhang (ORCID: https://orcid.org/0000-0001-6670-3057)
- Xiaopeng Deng (ORCID: https://orcid.org/0000-0002-2987-505X)
- Xudong Zhu (ORCID: https://orcid.org/0000-0002-0324-9042)
- Pete Smith (ORCID: https://orcid.org/0000-0002-3784-1124)
- Zhangcai Qin (ORCID: https://orcid.org/0000-0001-9414-4854)
- Josep G. Canadell (ORCID: https://orcid.org/0000-0002-8788-3218)
- Tingting Li (ORCID: https://orcid.org/0000-0002-6338-2769)
- Philippe Ciais (ORCID: https://orcid.org/0000-0001-8560-4943)
- Susan C. Cook‐Patton (ORCID: https://orcid.org/0000-0002-7194-4397)
- Yijie Wang (ORCID: https://orcid.org/0000-0002-3164-8737)
- Yifan Xu (ORCID: https://orcid.org/0000-0002-5408-8971)
- Chao Yue (ORCID: https://orcid.org/0000-0003-0026-237X)
- Yuan Wenping
- Hao Xu (ORCID: https://orcid.org/0000-0002-3725-9505)
- Wenjuan Sun (ORCID: https://orcid.org/0000-0002-9667-1882)
- Yakun Zhu
Institutions
- The Nature Conservancy (US)
- Commonwealth Scientific and Industrial Research Organisation (AU)
- Centre National de la Recherche Scientifique (FR)
- Xiamen University (CN)
- University of Aberdeen (GB)
- Université de Versailles Saint-Quentin-en-Yvelines (FR)
- Chinese Academy of Sciences (CN)
- Peking University (CN)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Institute of Soil and Water Conservation (CN)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (CN)
- Laboratoire des Sciences du Climat et de l'Environnement (FR)
- Institute of Atmospheric Physics (CN)
- Institute of Botany (CN)
- Smithsonian Environmental Research Center (US)
Publication Details
- Journal
- Science
- Published
- 2025-08-28
- DOI
- https://doi.org/10.1126/science.adj6841
- Citations
- 15
- Primary Topic
- Forest Management and Policy
- Type
- article
- Field-Weighted Citation Impact
- 16.58