Still, the synthesis of six independent evaluations of the effectiveness of 44 REDD+ projects found that four in five projects successfully protected forests. The study represented almost half of the projects producing REDD+ carbon credits by 2020.

‘A key take-home message is that “bad credits” do not necessarily mean “bad projects”. Many projects have successfully slowed deforestation, even if more credits were sold than are justified,’ said Professor Julia Jones at Bangor University, a co-author of the study. It found that nine REDD+ projects in particular accounted for much of the over-crediting.

She added: ‘The over-crediting scandal in the voluntary carbon market has left many with the unhelpful impression that anything to do with funding tropical forest conservation through carbon finance is a bit dodgy. It is important to set the record straight, as forest conservation is so vital to tackling climate change.’

Dr Tom Swinfield, a researcher in the University of Cambridge’s Department of Zoology and first author of the study, said: ‘We found that many REDD+ projects were at far lower risk of deforestation than anticipated by project-led evaluations. Credits were issued based on predictions that these forests were at imminent risk of deforestation, but in reality this risk was often lower.’

According to the University of Cambridge, carbon credits are generated by comparing the anticipated deforestation in a region before protection, with the projected deforestation once areas of forest are protected through a REDD+ project. This depends on accurately selecting other, unprotected areas of forest against which robust comparisons can be made. The problem many independent evaluators have discovered is that the comparison areas chosen by crediting agencies were often more exposed to deforestation than project areas would have been, so too many credits have been issued.

The researchers say to avoid over-crediting, future REDD+ projects must draw on more representative reference forests to better assess the true contribution of projects to forest protection.

Elsewhere, Octopus Energy Generation has announced that it will invest $500mn in forestry projects in the US with Living Carbon, with the aim of removing up to 50mn tonnes of atmospheric carbon.

Maddie Hall, Founder and CEO at Living Carbon, said: ‘Our partnership with Octopus takes us from early-stage implementation to delivering long-term carbon removal at scale with institutional capital. This is a sign that this market is maturing into real project finance as corporate commitments to net zero increase.’