Humans and climate change have transformed 10 of the world’s most highly protected forests into net emitters of carbon over the past 20 years, according to a new report.
Land clearance and deforestation, as well as forest fires of increasing scale and severity, meant the forests released more carbon into the air than they stored, the study by UNESCO, the World Resources Institute, and the International Union for Conservation of Nature (IUCN) found.
Among the World Heritage forests contributing to emissions were the Sumatran rainforest, the Kinabalu Park in Malaysian Borneo, and the Blue Mountains in Australia.
Yosemite and the Grand Canyon in the United States were also net emitters.
“Our finding that even some of the most iconic and best protected forests, such as those found in World Heritage sites, can actually contribute to climate change is alarming and brings to light evidence of the severity of this climate emergency,” said Tales Carvalho Resende, of UNESCO and co-author of the report.
The researchers used global satellite mapping with ground level monitoring to estimate the gross and net carbon absorbed and emitted by the World Heritage forests between 2001 and 2020, and to determine the causes of some of the emissions.
They found that, as a whole, World Heritage forests absorbed the equivalent of approximately 190 million tons of carbon dioxide from the atmosphere each year, which is equivalent to about half the United Kingdom’s annual emissions from fossil fuels.
But they also found that some sites, despite remaining net carbon sinks overall, showed spikes or clear upward trajectories in emissions that threatened the strength of the future sink.
“We now have the most detailed picture to date of the vital role that forests in World Heritage sites play in mitigating climate change,” Resende said. “All forests should be assets in the fight against climate change.”
There are 257 World Heritage forests across the globe, which cover a combined area of 69 million hectares (170 million acres) – roughly twice the size of Germany – and represent some of the world’s most biodiverse ecosystems.
They not only absorb carbon dioxide from the atmosphere, but also store substantial amounts of carbon – approximately 13 billion tons, more than the carbon in Kuwait’s proven oil reserves, according to the report.
The researchers warned continued landscape fragmentation and degradation as a result of human activity was likely to lead to more frequent and intense climate-related wildfires, and urged governments to reinforce protection and improve land management at the World Heritage sites, as well as their surrounding areas.
It also recommended protection of the forests be integrated into the world’s climate strategies.
“Protecting World Heritage sites from increasing fragmentation and escalating threats will be central to our collective ability to address climate change and biodiversity loss,” Tim Badman, Director of IUCN’s World Heritage Programme, said in a statement.
10 carbon-emitting World Heritage forests
Tropical Rainforest Heritage of Sumatra, Indonesia
Río Plátano Biosphere Reserve, Honduras
Yosemite National Park, US
Waterton Glacier International Peace Park, Canada/US
Barberton Makhonjwa Mountains, South Africa
Kinabalu Park, Malaysia
Uvs Nuur Basin, Russian Federation/Mongolia
Grand Canyon National Park, US
Greater Blue Mountains Area, Australia
Morne Trois Pitons National Park, Dominica