Only a small number of tropical forests carbon offset projects have achieved significant cuts in deforestation, with just 19 per cent meeting their reported targets, according to a new study published in Science.
These offset projects are a part of the REDD+ programme, standing for Reducing Emissions from Deforestation and Degradation Plus. It is an international initiative aimed at reducing greenhouse gas emissions by offering economic incentives to developing countries to maintain forest cover, enhance carbon stocks, and promote human well-being.
Tropical forests play a crucial role in supporting biodiversity and ecosystem services. However, forest loss and degradation have led to an emissions of roughly five billion metric tons of carbon dioxide annually—second only to fossil fuel consumption.
REDD+ projects pay governments, organisations, communities, and individuals in forest landscapes for activities that preserve forests and avoid forest-related greenhouse gas emissions (GHG).
Globally, more than 350 ‘voluntary’ REDD+ projects operate worldwide, most of which are funded through the sale of carbon offsets, which are mechanisms through which buyers like polluting industries fund efforts that remove or avoid GHG emissions to “offset” their own emissions. This helps corporations compensate for their carbon footprints and meet their environmental objectives. These projects are under the voluntary carbon market, a decentralised market where private actors voluntarily buy and sell carbon credits that represent removals or reductions of carbon dioxide. One carbon credit equals 1 tonne of CO2 equivalent avoided or removed.
These projects grew popular, accounting for two-thirds of the 227.7 million offsets traded in carbon markets from the land-use sector (excluding agriculture), and a total market value of $1.3 billion in 2021.
However, such projects have been challenged for overstating climate benefits, leading to a 62 per cent drop in the value of REDD+ carbon offsets between 2022 and 2023.
The study analysed 54 REDD+ projects across South America (Brazil, Colombia, and Peru), Africa (Central African Republic, Democratic Republic of Congo, Madagascar, Mozambique, Sierra Leone, Tanzania, and Zambia), and Southeast Asia (Cambodia and Laos). These projects are registered with of voluntary REDD+ projects certified by Verra’s Verified Carbon Standard (VCS).
Their analysis showed that 17 per cent of the project units witnessed higher losses of forests designated in the REDD+ area compared to that of its control. For example, the Brazilian Serra do Amolar project and the Ankeniheny-Zahamena Corridor project in Madagascar both experienced the highest forest loss of more than 1,500 ha annually in project sites compared with that of their controls.
However, the study recorded some hope in a few projects. Nearly one-third of the project units saw significantly lower forest loss than expected, suggesting likely successful climate mitigation. Examples include the Portel-Pará REDD+ project in the Brazilian Amazon that saw a decrease in forest loss of 1,362.5 ha per year after REDD+ implementation, saving 19.1 thousand ha by 2022.
Compared to previous studies, the new research estimates a nearly twofold increase in the percentage of tradable carbon credits of 13.2 per cent, compared with the 6 to 7 per cent reported previously. This can be attributed to including a broader and more recent set of REDD+ projects while excluding those with incomplete data or spatial inconsistencies and using more robust analytical procedures.
Still, there are concerns. “Despite more optimism for tropical voluntary REDD+ projects that emerges from our results, we also confirm that many projects substantially over-credit their climate benefits,” reads the paper.
One source for overestimation, the paper added, stems from the assumption that historical deforestation trends can reliably forecast future risk.
In reality, shifting socioeconomic and political conditions influenced deforestation. For example, deforestation rates in the Brazilian Amazon more than doubled from 2019 to 2021 under Jair Bolsonaro, former president of Brazil — this pattern was seen in Brazil. The paper calls for explicitly incorporating country-specific governmental cycles into Verra’s methods.