Map on the most important protected areas to avert a climate catastrophe
Avoiding catastrophic climate change requires rapid decarbonisation and improved ecosystem stewardship at a planetary scale. There are some natural places that we cannot afford to lose due to their irreplaceable carbon reserves.
In a recent study, an international research team maps ‘irrecoverable carbon’ globally to identify ecosystem carbon that remains within human purview to manage and, if lost, could not be recovered by mid-century, by when net-zero emissions has to be reached to avoid the worst climate impacts. These stores of "irrecoverable carbon" are primarily mangroves, tropical forests and peatlands, as well as old-growth forests in temperate latitudes.
The special protection of these crucial areas has another advantage: they are also havens of biodiversity. Thus, the targeted protection of these irretrievable carbon reservoirs can simultaneously make a significant contribution to species conservation.
“The consequences of releasing this stored carbon would stretch on for generations, undermining our last chance to stabilise Earth’s climate at tolerable levels for nature and humanity,” said Johan Rockström, Conservation International chief scientist and co-director of the German Potsdam Institute for Climate Impact Research (PIK), 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 prioritising these unique ecosystems.”
The new worldwide map, published in November 2021 in the journal Nature Sustainability, shows that half of Earth’s irrecoverable carbon is highly concentrated on just 3.3 per cent of land – primarily old-growth forests, peatlands and mangroves. These vast reserves of carbon are equivalent to 15 times the global fossil fuel emissions released last year.
Researchers say that knowing which ecosystems contain the greatest irrecoverable carbon stores can help governments focus global efforts to protect 30 per cent of land by 2030. Targeted conservation would yield big gains – increasing the land-under-protection key areas by just 5.4 per cent would keep 75 per cent of Earth’s irrecoverable carbon from being released into the atmosphere, researchers found.
Irrecoverable carbon areas overlap places with high biodiversity concentration
An accompanying report, also released in November, 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 paper calls for the creation of “irrecoverable carbon reserves”, new, area-based conservation measures designed to ensure irrecoverable carbon remains in these critical ecosystems.
According to the Nature Sustainability study, the largest and highest-density irrecoverable carbon ecosystems include
- The tropical forests and peatlands of the Amazon biome (31.5 gigatonnes irrecoverable carbon);
- The Congo Basin (8.2 gigatonnes);
- Islands of Southeast Asia (13.1 gigatonnes);
- The temperate forests of north-western 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
- 52 per cent of the world’s irrecoverable carbon currently lacks any formal protection or management;
- More than a third of irrecoverable carbon (46.7 billion gigatonnes) is stored within the government-recognised 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).