Carbon offsets from forest conservation projects have been overestimated

A new analysis reveals that emission reductions from forest conservation projects – sometimes used to “offset” carbon emissions from other sources – have been overestimated. According to a new study, many REDD+ (Reduced Emissions from Deforestation and Forest Degradation) programs have not significantly reduced deforestation, and those that did had benefits substantially lower than have been claimed. “The implications of [the study’s] findings are far reaching,” write Julia Jones and Simon Lewis in a related Perspective. “Misleading offsets carry negative consequences for the climate because they are not offsetting the emissions release, for forest conservation because they are not reducing deforestation as much as claimed, and for the future finance of forest conservation because the reputational risks of being tainted by accusations of greenwash may deter future investments.” Some private companies, individuals, and governments offset their carbon emissions by investing in projects that would prevent emissions that would have otherwise occurred, such as conservation projects designed to reduce deforestation. While carbon offsets from REDD+ programs are often traded as credits in carbon markets (with an estimated value of $1.3 billion USD) and claimed when calculating carbon emission budgets, there has been little rigorous evidence as to whether the projects deliver on their promises. Here, Thales West and colleagues evaluated 26 REDD+ projects in 6 countries worldwide and used synthetic control methods to estimate how much deforestation the projects prevented. West et al. found that most projects did not substantially reduce deforestation, and that the few that did reduced it much less than had been claimed. Furthermore, the authors show that a subset of 18 REDD+ projects have generated 62 million carbon-offset credits – 14.6 million of which have already been used by entities around the world to offset their carbon emissions. According to the study’s estimates, these projects have been used to offset nearly 3 times more carbon than their actual contributions to climate change mitigation, with 47.7 million more carbon offset-credits currently readily available on the market. “Methodologies used to construct deforestation baselines for carbon offset interventions need urgent revisions to correctly attribute reduced deforestation to the projects, thus maintaining both incentives for forest conservation and the integrity of global carbon accounting,” write West et al.