傅伯杰院士团队在Nature Climate Change发文评估中国生态系统管理对减缓气候变化的贡献
Natural climate solutions (NCS), a suite of land-management options including protecting, restoring and sustainably managing ecosystems, provide readily implementable approaches to sequester carbon in terrestrial pools and/or reduce GHG emissions. NCS are a complement to, not a substitute for, emissions reductions related to decreased use of fossil fuels and decarbonization of energy and transportation sectors. They are expected to slow the rate of global warming in the next 10–40 years, in parallel with the development of mitigation technologies and energy transformation.
Following the first submission in 2015, China submitted its updated Nationally Determined Contributions (NDCs) in 2021. This included a ‘net-zero’ commitment, with a peak in CO2 emissions before 2030 and net carbon neutrality being achieved by 2060. Over the past decades (especially since 1999), China has strengthened its efforts in ecological restoration and protection. While not all the projects were originally designed for carbon sequestration and climate change mitigation, collectively they made a substantial contribution to China’s terrestrial ecosystem carbon sink. Some adaptive action strategies such as China’s Achievements, New Goals and New Measures for Nationally Determined Contributions and Master Plan of Major Projects of National Important Ecosystem Protection and Restoration (2021–2035) have been released, proposing a series of strategies for ecosystem management in the next decades to support implementation of the NDCs. So far, the contributions to emissions reductions from recent projects equivalent to NCS activities have not been fully quantified. More important, the mitigation potential of future NCS activities and their contribution to China’s climate goals is largely unknown.
In this Article, we quantified 16 distinct pathways to provide an integrated evaluation of the climate mitigation capacity of previous projects during 2000–2020 and the future NCS potentials during 2020–2030 and 2020–2060 by conserving, restoring and improving management of forests, croplands, grasslands and wetlands in China. The evaluation of the mitigation capacity of previous projects for 2000–2020 is a foundation to understand the historical contribution and a baseline for setting feasible boundaries for future additional NCS pathway projections. We first provide estimates of the historical mitigation capacity of projects during 2000–2020, as well as the future ‘maximum additional mitigation potential’ (MAMP) of NCS by additional stewardship options under biophysical constraints in the next 10 (by 2030) and 40 (by 2060) years, measured in CO2 equivalents per year (CO2e yr-1). We then constrain NCS levels by mitigation cost thresholds. We note that the essence of NCS is to seek new opportunities and approaches with additionality over the baseline (2000–2020 in this study).
Lu, N., Tian, H., Fu, B. et al. Biophysical and economic constraints on China’s natural climate solutions. Nat. Clim. Chang. (2022). https://doi.org/10.1038/s41558-022-01432-3