The report from UNESCO found these sites can absorb approximately 190 million tons of carbon dioxide from the atmosphere each year -- roughly half the amount of the United Kingdom's annual fossil fuel emissions.
Given the scale of these forests, Tales Carvalho Resende, project officer at UNESCO's natural heritage unit and co-author of the report, says this is increasingly a global issue, meaning global action is needed. But the report shows that since 2000, the threats of extractive industries, environmental degradation and climate change have been reported in roughly 60% of the World Heritage sites, which have lost more than 8.6 million acres of forests, larger than the size of Belgium. Out of 10 sites they found to have flipped to carbon emitters, three are located in the United States.
Most of the sites that sequester the most carbon dioxide were in tropical and temperate regions, such as South America and Australia. Although those sites are still sequestering carbon, researchers said there are signs that more of them could join the rest in becoming carbon sources. "We have seen some wildfires in some sites that have emitted more than 30 million megatons of CO2 -- that's more or less what Bolivia emits in from fossil fuels in one single year," Resende said.
"Our analysis illustrates how we can stop taking nature for granted and start putting a value on the climate benefits generated by these and other important forest sites around the world," Harris said.