A rigorous analysis of 44 carbon credit projects found that most reduced deforestation to some degree, yet they issued credits for nearly 11 times more forest protection than actually occurred on average.
The research, led by Tom Swinfield at the University of Cambridge, examined projects developed after United Nations guidelines for reducing emissions from deforestation and forest degradation were established in the 2010s. Thirty-six of the projects achieved at least slightly less deforestation than expected without intervention, with only one leading to significantly more tree loss. However, just one in eleven credits sold was justified by real reductions, a figure inflated by projects that issued the most credits without delivering results.