The forests of Brazil’s Serra da Mantiqueira—or at least what’s left of them—can invite hasty judgment. Stretching for 200 miles near the border of Sao Paulo state, the Mantiqueira region is part of the once-vast Atlantic Forest. Centuries ago, this tropical forest famous for its diversity covered an area twice the size of Texas, in a north-south strip parallel to the coast. Today, the Mantiqueira’s mountain slopes stand largely stripped of trees, covered instead with cattle pastures and farm fields. “We have only 12 percent of the original Atlantic Forest left,” says Rubens Benini, a Nature Conservancy scientist who has worked for 22 years to restore Brazil’s forests. “And it is very fragmented.”

The history of the Mantiqueira region is a classic tale of widespread environmental destruction in the name of economic progress. But the story of the region’s tropical forests may not be over, yet.

More than a decade ago, the government of Extrema, a municipality at the Mantiqueira region’s edge, began a tree-planting program as part of an effort to help secure its water supply. The name Mantiqueira comes from an indigenous word meaning “where the clouds lie.” The mountain peaks harbor thousands of springs and streams, waterways that supply Sao Paulo and Rio de Janeiro. Forests help hold water in soils and slow the runoff of rainfall into streams and rivers. Without forests, the Mantiqueira’s streams now shift dramatically from high flows in the rainy season to low flows in dry times. After the work in Extrema helped moderate some stream flows, local farmers and ranchers joined in the reforestation effort—as did TNC. Since 2005, the project has replanted nearly 5,000 acres of forest, and the planting continues.

In 2016, Brazil signed the Paris Agreement and promised to slash its emissions to 43 percent below its 2005 level by 2030. For Benini, that commitment put Extrema’s effort in a new light. Extrema had replanted trees to protect its water, but those same trees were also absorbing carbon dioxide every day. What if there were dozens more Extremas? Hundreds? Brazil could meet part of its climate commitment and better withstand future droughts by putting trees back on marginal lands that had once been forest.

Brazil has since set a target of reforesting 30 million acres across its territory, part of a growing global recognition that nature itself can help nations meet their climate commitments. Managed intelligently, forests, wetlands and soils all have the ability to store carbon. The Conservancy’s own researchers were the first to take a comprehensive look at just how much good conservation and land management changes could do, not just in forests but in all kinds of landscapes.

The answer, it turns out, is a lot.

Benini now leads TNC’s forest-restoration strategy for Latin America. He remains at the forefront of an ambitious initiative to help Brazil take the Extrema model to another 283 municipalities and thereby restore nearly 3 million acres of forest. Doing so will require help from international funders, but such investment will be well worth the price, says Benini. The initiative will take approximately 280 million tons of excess carbon dioxide out of the atmosphere over 30 years—the equivalent of the emissions of more than 55 million cars—and fulfill 10 percent of Brazil’s reforestation goal.

“This is a new way to look at the landscape,” Benini says. “When we are talking about restoration, we’re not just talking about bringing the forest back. We’re talking about tackling climate change.”