The UNESCO report found that these sites can absorb around 190 million tonnes of carbon dioxide from the atmosphere each year, or about half of the UK’s annual fossil fuel emissions.
But over the past 20 years, many of these sites have shown increased emissions, some even exceeding the amount of carbon they were removing from the atmosphere.
UNESCO researchers said two main factors are tipping forests from sinks to sources: extreme weather events caused by climate change, including forest fires, storms and drought; and human pressures associated with land use such as illegal logging, timber harvesting, and agricultural practices such as cattle grazing.
Given the scale of these forests, Tales Carvalho Resende, project manager at UNESCO’s Natural Heritage Unit and co-author of the report, says it is increasingly a problem. global, which means global action is needed.
From the Congo Basin to Redwood National and State Parks, the world’s 257 World Heritage forests cover more than 170 million acres of land, almost twice the size of Germany.
But the report shows that since 2000, threats from extractive industries, environmental degradation and climate change have been reported in around 60% of World Heritage sites, which have lost more than 8.6 million acres. of forests, larger than the size of Belgium. Of 10 sites they discovered to have become carbon emitters, three are in the United States.
The report’s findings are a timely warning of the limits of trees and forests as a climate solution. Leaders and negotiators meet in Glasgow, Scotland from Sunday to discuss ways to limit global warming, and planting trees is one of the top four priorities set by the UK government, which chairs the ‘event.
Protecting forests and planting trees have enormous potential for absorbing carbon from the atmosphere, but in a rapidly changing world characterized by a wild climate, trees in areas prone to forest fires could become a major source of carbon. part of the problem, rather than the solution, as these UNESCO sites show.
The authors point out that this is the first time that researchers have quantified how the world’s forests sequester atmospheric carbon dioxide. Over the centuries, World Heritage forests have stored approximately 13 billion tonnes of carbon, which exceeds the total amount of carbon in Kuwait’s oil reserves.
“We can now see the important role that World Heritage forests play in stabilizing the global climate,” Nancy Harris, research director for Global Forest Watch at the World Resources Institute and co-author of the report, told CNN. “And the truth is, we completely underestimate and underestimate them. “
Most of the sites that sequester the most carbon dioxide are in tropical and temperate regions, such as South America and Australia. Although these sites still sequester carbon, the researchers said there were signs that more of them could join with others in becoming carbon sources.
Forest fires, in particular, have burned large areas of these forests in recent years. While fires are a vital part of the forest ecosystem, many plant species depend on them to disperse their seeds, scientists say fires are escalating, potentially releasing long-stored carbon in the soil and growing them. trees.
Over the past decade, warming temperatures and dry conditions have prepared much of the environment for forest fires. The report highlighted several examples of significant fires that have occurred over the past decade at World Heritage sites, including Lake Baikal in Russia in 2016, and the Tasmanian Wilderness and the Great Blue Mountains in Russia. Australia in 2019 and 2020.
“We’ve seen forest fires at some sites that have emitted over 30 million megatons of CO2 – that’s more or less what Bolivia emits from fossil fuels in a single year,” Resende said.
“A single event can actually be the broadcasts of an entire country,” he added. “And keep in mind that the emissions that were taken into account in the study are only within the boundaries of the sites, so that means they only represent a small part of the fires in the landscape more large. “
The report builds on recently published maps that track the global exchange of carbon between forests and the atmosphere over the period 2001 to 2020, using site-level monitoring to analyze climate impacts of forests as well. as the consequences of human activities on these World Heritage sites. sites.
“Our analysis shows how we can stop taking nature for granted and start valuing the climate benefits generated by these and other important forest sites around the world,” said Harris.
Forests play a vital role in all societies. According to the International Union for the Conservation of Nature, which also contributed to the report, nearly 25% of the world’s population – many in developing countries – depend on forests for their livelihoods. In addition, forests generate up to $ 100 billion a year in goods and services. It is also home to 80% of the Earth’s terrestrial biodiversity.
The ability of forests to prevent the climate crisis from spiraling out of control makes the threats they face all the more worrying, said Resende.
World leaders will meet in Glasgow, Scotland next week for the UN-brokered international climate negotiations, where the focus will be on countries pledging to further reduce fossil fuels and set a date end to coal. They will also discuss stronger commitments to protect and restore the world’s forests as carbon sinks and to end deforestation.
“We really hope to trigger climate action, to save these gems which are World Heritage sites,” Resende said. “They are laboratories for overall environmental changes, not only linked to climate but also to biodiversity. We want to facilitate dialogues with key stakeholders to actually fund and deliver sustainable investments to these sites. “