Learning lessons from over-crediting to ensure additionality in forest carbon credits
Thomas Swinfield, Abby Williams, David Coomes, Michael Dales, Patrick Ferris, Alejandro Guizar-Coutiño, James Hartup, Jody Holland, Sadiq Jaffer, Julia P.G. Jones, Miranda Lam, Srinivasan Keshav, Anil Madhavapeddy, Eleanor Toye Scott, Thales West, and Andrew Balmford.
Working paper at Cambridge Open Engage.
Independent evaluations have shown substantial over-issuance of REDD+ (Reducing Emissions from Deforestation and Degradation) credits traded on the voluntary carbon market. To improve credit integrity we need to synthesise these evaluations to understand the additional forest conservation achieved by first-generation REDD+ projects, and explore the mechanisms by which over-crediting occurred. We bring together six independent ex-post evaluations of avoided deforestation by 44 REDD+ projects. These consistently show that most projects successfully reduced deforestation, but they also claimed an aggregate of 10.7 times more avoided deforestation than independent evaluations indicate is justified. This discrepancy is not an artefact of which forest cover layer is used but is linked to selection bias in projects’ choices of control areas and modelling approaches. Given the need to close the forest finance gap, there is unwillingness to abandon the potential of the voluntary carbon market because of past failures. Current initiatives which transfer assessment to unconflicted parties and eliminate methodological flexibility is critical but insufficient. Ex post certification against a credible counterfactual is also necessary to ensure sufficient integrity in carbon markets for them to contribute to the vital task of slowing deforestation.