A major new study has found that carbon credit projects designed to protect tropical forests have delivered real environmental benefits, despite issuing far more carbon credits than they should have. Researchers say these projects played a crucial role in reducing forest loss across some of the world’s most important ecosystems, but large-scale over-crediting has damaged trust in the voluntary carbon market.
The study, led by the University of Cambridge and published in Nature Communications, found that nearly 11 times more carbon credits were issued by REDD+ projects than were justified. REDD+, which stands for Reducing Emissions from Deforestation and Forest Degradation, uses carbon credit funding to conserve forests and reduce greenhouse gas emissions.
Many Projects Reduced Forest Loss Despite Carbon Credit Issues
Researchers reviewed 44 REDD+ projects that represented almost half of all such carbon credit projects operating by 2020. The findings showed that four out of five projects successfully reduced deforestation and helped protect tropical forests in regions such as the Amazon Basin and the Congo.
However, the study found that many projects had overestimated the threat of deforestation in their areas, resulting in the issue of far more carbon credits than actual forest protection justified. Scientists explained that project evaluations often used comparison forests that faced much higher deforestation risks than the protected project sites, making the conservation impact appear greater than it really was.
Experts said a small group of nine high-crediting projects was largely responsible for the market distortion, creating an impression that the entire system was unreliable.
Market Collapse Highlights Need for Better Regulation
The over-crediting issue has severely impacted confidence in the carbon market. The voluntary carbon market, once valued at nearly 2 billion dollars in 2022, has now dropped to around one-fourth of that value following public criticism and scientific reviews.
Researchers stressed that “bad credits” do not necessarily mean “bad conservation projects.” Many forest protection efforts still generated real climate and biodiversity benefits even though they sold too many credits.
The study called for future carbon credit systems to rely on better and more independent monitoring methods, including stronger comparison models and retrospective project performance checks, to ensure credits reflect actual environmental gains.
Forests Remain Central to Climate Protection
Scientists said carbon markets continue to remain one of the few financial tools capable of generating large-scale funding for tropical forest conservation. These forests play a critical role in storing carbon, protecting biodiversity and reducing global warming.
The researchers argued that instead of abandoning the REDD+ system, future projects should issue fewer carbon credits at higher prices while ensuring that each credit reflects genuine emissions reduction. They also recommended using independent data providers to avoid bias in evaluating project performance.
Experts believe the findings are important in restoring confidence in climate finance while ensuring that tropical forest protection continues. As global deforestation remains a major driver of climate change, researchers say improving carbon market transparency will be essential for both environmental protection and long-term climate action.