Tropical forest carbon offsets deliver partial gains amid persistent over-crediting

[Geoengineering News]

https://www.science.org/doi/10.1126/science.adw4094

Authors: Yuzhi Tang, Chao Yang, Haishan Wu, Zihao Xu et al.

09 October 2025

DOI: 10.1126/science.adw4094

Editor’s summary

Forest degradation is a major contributor to greenhouse gas emissions, such that forest protection projects are used as carbon offsets for greenhouse gas–producing activities in voluntary carbon markets. Recently, the effectiveness of carbon-offsetting programs such as REDD+ (Reducing Emissions from Deforestation and Degradation Plus) has been called into question, causing a decline in carbon offset values. Tang et al. addressed this question with updated analyses incorporating many projects and carefully chosen controls. Across 52 REDD+ Avoided Unplanned Deforestation projects from 12 countries in South America, Africa, and Southeast Asia, the authors found greater climate benefits than previous studies but low efficacy overall: Less than 20% of projects met their emissions targets. Project success and overestimation both varied considerably between countries. —Bianca Lopez

Abstract

REDD+ (Reducing Emissions from Deforestation and Degradation Plus) projects generate carbon credits to offset emissions, but recent studies have questioned their effectiveness. We evaluated 52 voluntary REDD+ projects across 12 tropical countries using synthetic control methods. Only a minority of project units showed statistically significant reductions in deforestation, and just 19% met their reported emissions targets. Nonetheless, many underperforming projects still delivered partial climate benefits, with an estimated 13.2% of tradable credits supported by counterfactual analysis. Effectiveness varied by region, with stronger performance in Brazil and Africa. Although systematic over-crediting remains a concern, our results suggest greater climate benefits than previous assessments. Improving baseline methodologies and strengthening verification frameworks will be essential for enhancing the credibility and impact of forest carbon offsets.

Source: Science