Cheng Samantha H, Costedoat Sebastien, Sigouin Amanda, Calistro Gabriel F, Chamberlain Catherine J, Lichtenthal Peter, Mills Morena, Nowakowski A Justin, Sterling Eleanor J, Tinsman Jen, Wiggins Meredith, Brancalion Pedro H S, Canty Steven W J, Fritts-Penniman Allison, Jagadish Arundhati, Jones Kelly, Mascia Michael B, Porzecanski Ana, Zganjar Chris, Brenes Carlos L Muñoz
World Wildlife Fund, 1250 24th St NW, Washington, DC, 20037, USA.
Center for Biodiversity and Conservation, American Museum of Natural History, New York, NY, 10024, USA.
Environ Evid. 2023 Oct 25;12(1):21. doi: 10.1186/s13750-023-00312-3.
BACKGROUND: Nature-based interventions (NbIs) for climate change mitigation include a diverse set of interventions aimed at conserving, restoring, and/or managing natural and modified ecosystems to improve their ability to store and sequester carbon and avoid greenhouse gas (GHG) emissions. Recent projections estimate that terrestrial NbIs can lead to more than one-third of the climate change mitigation necessary to meet the Paris Climate Agreement by 2030. Further, these interventions can provide co-benefits in the form of social and ecological outcomes. Despite growing recognition of the potential benefits, a clear characterization of the distribution and occurrence of evidence which supports linkages between different types of NbIs and outcomes for climate change mitigation, ecosystems, and people remains poorly understood. METHODS: This systematic map assesses the evidence base on the links between NbIs and climate change mitigation, social, and ecological outcomes in tropical and subtropical terrestrial regions. We searched three bibliographic databases, 65 organization websites, and conducted backward citation chasing within 39 existing evidence syntheses to identify relevant articles. Additionally, we reached out to key informants for additional sources of evidence. We then used machine learning to rank returned results by relevance at the title and abstract stage and manually screened for inclusion using predefined criteria at the title, abstract, and full text stages. We extracted relevant meta-data from included articles using an a priori coding scheme. Lastly, we conducted a targeted, complementary search to identify relevant review and synthesis articles to provide broader context for the findings of the systematic map. REVIEW FINDINGS: We included 948 articles in this systematic map. Most of the evidence base (56%) examined links between protection, natural resource management, and restoration interventions with changes to 'proxy' outcomes for climate change mitigation (changes to land condition, land cover, and/or land use). Other areas with high occurrence of articles included linkages between interventions within natural resource management and trees in croplands categories and changes to aboveground carbon storage and/or sequestration (17% of articles). A key knowledge gap was on measured changes in GHG emissions across all intervention types (6% of articles). Overall, articles in the evidence base did not often assess changes in co-benefits alongside direct or indirect changes for climate change mitigation (32%). In most cases, the evidence base contained studies which did not explicitly test for causal linkages using appropriate experimental or quasi-experimental designs. CONCLUSIONS: The evidence base for NbIs is significant and growing; however, key gaps in knowledge hamper the ability to inform ongoing and future investment and implementation at scale. More comprehensive evidence is needed to support causal inference between NbIs and direct outcomes for climate change mitigation to better determine additionality, permanence, leakage, and other unintended consequences. Similarly, priorities emerging from this map include the need for coordinated and harmonized efforts to collect diverse data types to better understand whether and how other outcomes (e.g. social, ecological) of NbIs can be achieved synergistically with mitigation objectives. Understanding potential benefits and trade-offs of NbIs is particularly urgent to inform rapidly expanding carbon markets for nature.
背景:基于自然的气候变化缓解干预措施(NbIs)包括一系列旨在保护、恢复和/或管理自然及人工改造生态系统的干预措施,以提高其储存和封存碳的能力并避免温室气体(GHG)排放。近期预测估计,到2030年,陆地NbIs可实现超过三分之一的《巴黎气候协定》所需的气候变化缓解目标。此外,这些干预措施还能带来社会和生态效益等协同效益。尽管人们越来越认识到其潜在益处,但对于支持不同类型NbIs与气候变化缓解、生态系统和人类成果之间联系的证据的分布和存在情况,仍知之甚少。 方法:本系统综述地图评估了热带和亚热带陆地地区NbIs与气候变化缓解、社会和生态成果之间联系的证据基础。我们检索了三个文献数据库、65个组织网站,并在39篇现有证据综述中进行了反向引文追踪,以确定相关文章。此外,我们还联系了关键信息提供者以获取更多证据来源。然后,我们使用机器学习在标题和摘要阶段按相关性对返回结果进行排序,并在标题、摘要和全文阶段使用预定义标准进行人工筛选以确定纳入文章。我们使用先验编码方案从纳入文章中提取相关元数据。最后,我们进行了有针对性的补充搜索,以确定相关的综述和综合文章,为系统综述地图的结果提供更广泛的背景。 综述结果:我们在本系统综述地图中纳入了948篇文章。大部分证据基础(56%)研究了保护、自然资源管理和恢复干预措施与气候变化缓解“替代”成果(土地状况、土地覆盖和/或土地利用变化)之间的联系。文章出现频率较高的其他领域包括自然资源管理和农田树木类别内的干预措施与地上碳储存和/或封存变化之间的联系(占文章的17%)。一个关键的知识空白是所有干预类型的温室气体排放的实测变化(占文章的6%)。总体而言,证据基础中的文章并不经常在评估气候变化缓解的直接或间接变化的同时评估协同效益的变化(32%)。在大多数情况下,证据基础中的研究没有使用适当的实验或准实验设计明确检验因果联系。 结论:NbIs的证据基础很重要且在不断扩大;然而,关键的知识空白阻碍了为大规模的当前和未来投资及实施提供信息的能力。需要更全面的证据来支持NbIs与气候变化缓解直接成果之间的因果推断,以更好地确定额外性、持久性、泄漏和其他意外后果。同样,本综述地图中出现的优先事项包括需要进行协调一致的努力,以收集各种数据类型,以更好地了解NbIs的其他成果(如社会、生态)是否以及如何能够与缓解目标协同实现。了解NbIs的潜在益处和权衡对于为迅速扩张的基于自然的碳市场提供信息尤为迫切。
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