Degraded forests and restoration areas in the tropics remove 107 million tons of carbon each year. That is 26 percent of the total released into the atmosphere from previous deforestation
by Matteo Cavallito
Forest restoration offsets only a minority share of CO2 emissions associated with deforestation, according to a research published in March 2023 in the journal Nature and conducted by the University of Bristol and Brazil’s National Institute for Space Research (INPE). The study used data from the Climate Change Initiative of ESA, the European Space Agency.
The researchers showed how degraded forests and restoration-prone areas in the tropics remove at least 107 million tons of carbon from the atmosphere each year. This amount, an ESA statement says, equals, by comparison, half of South America’s annual fossil fuel emissions. But it is not enough to make up for the overall damage caused by deforestation.
Carbon offset is just 26 percent
“Recovering tropical secondary and degraded forests now cover about 10% of the tropical forest area, but how much carbon they accumulate remains uncertain,” the research states. “On the basis of satellite data products, our analysis encompasses the heterogeneous spatial and temporal patterns of growth in degraded and secondary forests, influenced by key environmental and anthropogenic drivers.”
In restored areas, the study notes, the total amount of carbon recovered is sufficient to offset 26 percent of carbon emissions initially released due to the destruction and degradation of wet tropical forests.
“Our study provides the first pan-tropical, regional-scale estimates of carbon absorption in tropical forests recovering from degradation and deforestation,” says Viola Heinrich, a researcher at the Universities of Bristol and Exeter and co-author of the survey.
The record of Borneo’s forests
Using ESA satellite data and information on above-ground biomass occurrence and environmental variables, researchers analyzed forest regrowth in the Amazon, Central Africa and the island of Borneo where the main driver of deforestation is the expansion of the palm oil industry.
“In the first 20 years of recovery, regrowth rates in Borneo were up to 45% and 58% higher than in Central Africa and the Amazon, respectively,” the study further states. “This is due to variables such as temperature, water deficit and disturbance regimes.”
Borneo’s degraded forests, in other words, showed a much faster rate of carbon accumulation when compared with other regions. Restoration efforts, in each case, have been partial. In fact, one-third of forest areas degraded by logging or fire have since been completely cleared. “There are many forests across the tropics that have experienced severe, unsustainable, human-disturbances,” Heinrich added.
Conservation is worth 53 million tons of carbon per year
The satellite data used allow to describe changes in areas since the 1980s. Combining this information with biomass information has made it possible to estimate above-ground carbon accumulation in recovering forests throughout the tropics. Also for the future.
“Protecting old-growth forests is therefore a priority,” the research states. “Furthermore, we estimate that conserving recovering degraded and secondary forests can have a feasible future carbon sink potential of 53 Tg C year−1 across the main tropical regions studied.”
The researchers’ findings provide new support for the policy initiatives launched after COP26 in Glasgow with the release of the Declaration on Forests and Land Use, which set a goal of halting and reversing forest loss and land degradation by 2030. “Satellite Earth observations can not only help us to monitor deforestation, but they can also provide valuable information on secondary and degraded forests, such as the dynamic of their recovery and how much carbon they accumulate,” explained Clement Albergel, ESA climate applications expert. “This information is crucial to inform policymakers and support policy implementation.”