By Will McCarry
October 28, 2025
Protected areas slow the loss of Earth’s most critical carbon
CLIMATE
Less than 1 min
Beneath moss and flooded forests, within layers of roots and peat, lies a carbon vault that has been sealed for millennia.
New research from Conservation International shows that while much of this carbon is slipping away, a wave of protection is beginning to slow the loss.
The cost of inaction
These losses are not spread evenly. Forests accounted for more than half, and just 14 countries were responsible for three-quarters of the decline. Russia suffered the largest national loss, releasing 1.4 billion metric tons, nearly twice the amount lost by Brazil.
In the flooded forests of Cambodia's Tonlé Sap, ancient trees store climate-critical carbon.
“Irrecoverable carbon only goes in one direction,” said Conservation International scientist Allie Goldstein, who co-led the research. “Our goal is to keep as much of it in place as we can, because once it’s gone, it’s gone.”
Each metric ton lost represents a substantial loss of accumulated carbon, including soils formed over millennia, and forests that have stood for generations. The consequences are permanent — and global.
But the story is not all grim.
The data reveal a clear pattern: Where land is protected, carbon tends to stay in the ground. Unprotected areas lost nearly 7.2 percent of their irrecoverable carbon, compared with just 2.1 percent in formal protected areas. And where Indigenous lands overlap with official protection, losses are lowest of all.
“Every dataset tells the same story,” Goldstein said. “Protection — especially when Indigenous and local communities are involved — makes a real difference. But as the data shows, while protection slows loss, it’s not a silver bullet. These lands also face incredible pressure. They hold some of the world’s largest carbon stores, yet are often still exposed to logging, fire and other threats. It really underscores the challenges local stewards face in defending their forests and soils.”
A wave of targeted conservation
Despite pressures, a surge of new protected areas shows how quickly the tide can turn.
A grizzly bear wades through the wetlands of an old-growth temperate rainforest in British Columbia.
“At Conservation International, science doesn’t end in a report,” said Candido Pastor, who leads community-focused work in Amazonia for Conservation International.
“Through Vital Reserves, we’re putting data to work on the ground — showing how protecting irrecoverable carbon can also safeguard biodiversity. This project proves that conservation led by local governments and Indigenous Peoples works. The next challenge is ensuring it’s funded for generations to come.”
Mangrove roots and soils in South Sorong, West Papua, hold hidden stores of climate-warming carbon.
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