Forests around the world play a major role in curbing or contributing to climate change. Standing, healthy forests sequester more atmospheric carbon than they emit and act as a carbon sink; degraded and deforested areas release stored carbon and are a carbon source.
Forests are a net carbon sink globally, but there’s huge variation locally. Our analysis finds that forests managed by Indigenous people in the Amazon were strong net carbon sinks from 2001-2021, collectively removing a net 340 million tonnes of carbon dioxide (CO2) from the atmosphere each year, equivalent to the U.K.’s annual fossil fuel emissions.
Meanwhile, forests outside of the Amazon’s Indigenous lands were collectively a carbon source, due to significant forest loss. The research underscores the need to help Indigenous people and other local communities safeguard their forest homes and preserve some of the Amazon’s remaining carbon sinks.1
Carbon Flux: How Forests Serve As Carbon Sinks — or Carbon Sources
The world’s forests, which cover about 30% of Earth’s land, absorbed approximately 7.2 billion more tonnes of CO2 per year than they emitted between 2001 and 2021, about twice as much carbon as they released. Deforestation, degradation and other disturbances, however, have already turned some of the world’s most iconic forests into carbon sources and threaten to convert others.
The Amazon, the world’s largest tropical forest, remains a net carbon sink, but it teeters on the edge of becoming a net source. Southeastern Amazonia already emits more carbon than it sequesters. Over the past 40-50 years, an estimated 17% of Amazonian forest has been lost, of which over four-fifths was converted to agricultural land, mainly pastures.
Scientists estimate that deforesting 20% of the Amazon could push it past a tipping point, triggering a large-scale dieback that would release more than 90 billion tonnes of CO2 into the atmosphere (approximately 2.5 times greater than annual global fossil fuel emissions), transform the forest into a savannah and disrupt rainfall across South America.
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