Conservation, restoration, and ecosystem management can reduce greenhouse gas emissions or increase carbon dioxide sequestration, in what frequently are referred to as “natural climate solutions.” Such natural climate solutions have gained global attention in recent years as they could provide over one-third of the climate mitigation required to keep global warming under 2°C (3.6°F) by 2030. The authors mapped social, political, informational, and economic roadblocks that prevent implementation of natural climate solutions around the world, drawing on data from 352 peer-reviewed papers. The study presents a global, country-level analysis of a comprehensive set of constraints on natural climate solution implementation. The most common roadblock is lack of funding. Other common barriers include insufficient information on how to manage ecosystems for climate mitigation, ineffective policies, and disinterest or skepticism. However, the constellation of barriers varies by natural climate solution and country. Protecting or restoring wetlands, a complex task, is most often limited by lack of knowledge rather than lack of funds. Reforestation is often limited by concerns over negative equity impacts: For subsistence farmers, reforestation may make farmland less available, threatening livelihoods and food security. On the other hand, protecting existing forests faces barriers from lack of enforcement. Given the multiple constraints on natural climate solutions in every studied country, the authors suggest that the full benefit of such solutions is unlikely to be achieved in the near to medium term and that unlocking their full potential will require collaborations across sectors and disciplines. According to the authors, their maps can be used to improve estimates of the near-term feasible climate mitigation potential of natural climate solutions and inform equitable solutions for reducing the implementation gap through context-specific, integrated solutions.
PNAS Nexus
Global analysis of constraints to natural climate solution implementation
24-Jun-2025
This research project originated from a consultancy between H.B., M.H., W.E., and A.L. with The Nature Conservancy. The authors declare no other potential conflicts of interest.