The tropical forests and peatlands contain Earth’s rare “irrecoverable carbon” stores 

Arlington, VA (November 29, 2021) – The peatlands and forests of Central Africa’s Congo region are essential for global climate stability, according to new research out from Conservation International that maps the places on Earth that humanity must protect to avoid a climate catastrophe. These ecosystems contain what researchers call “irrecoverable carbon,” dense stores of carbon that, if released due to human activity, could not be recovered in time for the world to prevent the most dangerous impacts of climate change.   

The new worldwide map, published in the journal Nature Sustainability, builds on a landmark study that introduced the concept of irrecoverable carbon. The research finds that half of Earth’s irrecoverable carbon is highly concentrated on just 3.3% of land – primarily mangroves, old-growth forests and peatlands, like those found in the Congo Basin region. Globally, these vast reserves of carbon are equivalent to 15 times the global fossil fuel emissions released last year. 

According to the study, the waterlogged forests and tropical peatlands of the Congo Basin contain 8.1 billion metric tons of irrecoverable carbon – equivalent to more than 20 times Africa’s annual emissions – and have some of the highest concentrations of irrecoverable carbon worldwide. The Congo Basin contains 30 percent of the world’s tropical peatland carbon, now known to be among Earth’s most irreplaceable ecosystems for global climate security. 

Researchers say that knowing which ecosystems contain the greatest irrecoverable carbon stores can help governments focus global efforts to protect 30% of land by 2030. Targeted conservation would yield big gains – protecting just 5.4% of lands high in irrecoverable carbon, in addition to the amount currently within protected areas, would keep 75% percent of Earth’s irrecoverable carbon from being released into the atmosphere, researchers found.

“Knowing that irrecoverable carbon is concentrated in this region’s peatlands and trees can help guide the protection of these ecosystems we now know are essential for Earth’s climate” said Monica Noon, a Conservation International scientist and the study’s lead author. “The Congo Basin alone houses 6% of all the irrecoverable carbon on Earth – much of which is stored belowground, in the soils. Science is just beginning to understand the extent and importance of this massive carbon reserve. We are at a pivotal moment for climate action – the science and the solutions are here, and we know that areas like this are essential for global climate stability.”

An accompanying report also reveals that many of these irrecoverable carbon areas overlap with places containing high concentrations of biodiversity – meaning that protecting lands essential for climate stability would also conserve habitats for thousands of mammal, bird, amphibian and reptile species. The Congo Basin, for example, is a designated High Biodiversity Wilderness Area with 9,750 plant, 698 bird, 275 mammal and 142 reptile species – including many iconic species like Bonobos, Chimpanzees and Gorillas – living alongside the region’s 8.1 billion metric tons of irrecoverable carbon. The paper calls for the creation of “irrecoverable carbon reserves,” new, area-based conservation measures designed to ensure irrecoverable carbon remains in these critical ecosystems. 


The remote Cuvette Centrale peatlands in the central Congo basin is one of the most carbon-rich ecosystems on Earth. Photograph: Simon Lewis/University of Leeds

According to the Nature Sustainability study, the largest and highest-density irrecoverable carbon ecosystems, in addition to the Congo Basin, include

  • The tropical forests and peatlands of the Amazon biome (31.5 Gigatonnes irrecoverable carbon);
  • Islands of Southeast Asia (13.1 Gigatonnes);
  • The temperate forests of northwestern North America (5.0 Gigatonnes);
  • Mangroves, seagrasses and tidal wetlands globally (4.8 Gigatonnes).

The study also details how vulnerable irrecoverable carbon areas are to human activity and climate change – and how much irrecoverable carbon is stored within Indigenous and protected lands. These key findings include

  • Tropical ecosystems like those found throughout much of the African continent comprise most of the “doubly irreplaceable” land on Earth, making them high priority settings for both biodiversity conservation and climate change mitigation  
  • More than a third of irrecoverable carbon (46.7 billion Gigatonnes) is stored within the government-recognized lands of Indigenous peoples and local communities; 
  • Across ecosystems, the highest concentrations of irrecoverable carbon are found in mangroves (218 tonnes per hectare, on average), tropical peatlands (193 t/ha) and boreal wetlands (173 t/ha).

“The consequences of releasing this stored carbon would stretch on for generations, undermining our last chance to stabilize Earth’s climate at tolerable levels for nature and humanity,” said Johan Rockström, Conservation International chief scientist and co-director of the Potsdam Institute for Climate Impact Research, a leader in climate and sustainability research. “We must act now to safeguard the planet’s ability to serve as a carbon sink, which includes prioritizing these unique ecosystems.” 

In the last decade alone, agriculture, logging and wildfires have released at least 4 gigatonnes of irrecoverable carbon, equal to 5% of human-caused fossil fuel emissions over that time, the study reveals. Threats to irrecoverable carbon vary by ecosystem and location, researchers noted, but the most imminent and widespread risks come from legal rollbacks to protected areas that shrink or eliminate existing protections, land use changes for agriculture or development or climate-change-driven events such as forest fires or extreme weather. 

“Pressures from industrial logging and mineral extraction pose a direct threat to this region, considered the second lungs of the Earth (to the Amazon)” said Noon. “Changing rainfall patterns, exacerbated by climate change, threatens this important freshwater resource that captures large amounts carbon while providing drinking water and essential forest products that sustain local communities”.

“We have less than 10 years to cut emissions in half and prevent our climate and biodiversity from reaching an irreversible tipping point,” said Allie Goldstein, a co-author on the study and Conservation International’s director of climate protection. “The good news is that we haven’t yet reached that threshold. This is a rare scenario in which we have the time and information needed to prevent environmental disaster before it happens. Our research shows that investing in irrecoverable carbon reserves is a win-win-win approach that can improve the health of our climate, the health of Earth’s species and, ultimately, the health of humanity.”

Susan Cook-Patton, a coauthor of the paper and senior forest restoration scientist with The Nature Conservancy said that, “given the strengthened commitments that need to come out of the Glasgow UNFCCC COP this year, this global map represents a valuable addition to the science toolkit for climate policymakers. It is especially critical that governments fast-track protection of irrecoverable carbon stores that are at imminent threat of irreparable damage. This map can help find those locations before it’s too late.”

To secure the benefits of irrecoverable carbon, the study’s authors recommend 

  • Supporting Indigenous peoples and communities, who manage more than a third of Earth’s irrecoverable carbon but face increasing threats to their lands;
  • Immediately reversing policies and practices that threaten Earth’s last remaining irrecoverable carbon reserves; 
  • Expanding the area of irrecoverable-carbon lands under conservation, through protected areas as well as Indigenous and community-led conservation measures;
  • Prioritizing areas with high concentrations of irrecoverable carbon in strategies from national governments and multilateral funders such as the Global Environmental Facility, Green Climate Fund and World Bank; 
  • Designing comprehensive and collaborative land use planning practices that promote sustainable development and climate change resilience, such as fire and pest management and protecting coastal and freshwater wetlands to reduce flooding and storm surges. 

To read the entire study authored by scientists from Conservation International, The Nature Conservancy, Wildlife Conservation Society, Potsdam Institute for Climate Impact Research and the University of Wisconsin-Madison, click here. 

For additional information and to view some of the study’s maps, visit the irrecoverable carbon landing page here.


Read more on Peatlands:

Blog: What’s threatening the Congo Basin’s peatlands?
Scientists confirm presence of peatlands in Democratic Republic of Congo

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