Tropical forests, mangroves, peatlands, and other natural areas store massive amounts of carbon. The technical term for it is “irrevocable” because if it’s released now, due to deforestation or development, it won’t be possible to recapture it by the middle of the century, when the world needs to hit net zero emissions to avoid the worst impacts of climate change. A new study maps out which areas need the most protection.
“It’s those particularly important carbon stores in nature that we can’t afford to lose, since they couldn’t be restored by this climate deadline,” says Allie Goldstein, director of climate protection at Conservation International, the nonprofit that made the maps. Over the last decade, because of logging, agriculture, and wildfires, at least 4 billion metric tons of irrecoverable carbon have already been lost.
The study maps out only carbon that can be managed and protected, so it doesn’t include, for example, the melting permafrost in the Arctic, where climate change itself is driving the release of carbon. “We really wanted to focus on those ecosystems where people can manage whether that carbon is conserved or released into the atmosphere,” she says. The study also looked at areas where carbon was most vulnerable to being lost, and whether it could be recovered as plants and trees regrow over the next few decades.
The world’s irrecoverable carbon reserves store roughly 15 times more carbon that the global fossil fuel industry released last year. Irrecoverable carbon, it turns out, is concentrated in relatively small areas, including tropical forests and peatlands in the Amazon, islands in Southeast Asia, the Congo Basin, the temperate rainforest in the Pacific Northwest, and mangroves, seagrasses, and tidal wetlands around the world. In a previous study, the researchers found that it existed on six of seven continents. “But when we were able to actually map it at high resolution, we found that the top half of the irrecoverable carbon is concentrated in just 3.3% of land area,” Goldstein says. “That is really interesting, because it means that if we target and pinpoint conservation efforts, we can actually make a big difference on securing irrecoverable carbon in a relatively concentrated land area.”
Less than a quarter of the key areas are currently protected. Now, as more than 70 countries have committed to the 30×30 campaign, a push to conserve 30% of natural areas on the planet by 2030, the nonprofit hopes that the new map can help governments prioritize the areas that most urgently need protection. More than a third of irrecoverable carbon is on indigenous land, so new funding to support indigenous communities will also help. The work needs to happen now. “I think this map points us to a longer term vision,” Goldstein says. “It’s not 100 years—it’s really the next 10 years where we need to expand conservation efforts to really make a difference.”
Correction: We’ve updated this post to note that 4 billion metric tons (rather than 4 million) metric tons of irrecoverable carbon have already been lost in the last decade.