This soil is slowly burning, releasing CO2. The solution? Let water reclaim it
In the middle of Jörg Espig's hay field, along Germany's Baltic Sea coast, there's a spot where two worlds meet.
"Here's the dividing line," says Espig, a farmer who still talks with the accent and big-city brashness of his native Berlin. He takes just a few more steps through the knee-high grass, and suddenly the ground underfoot feels softer, like a giant sponge.
He's stepped from ordinary "mineral soil" composed of sand and clay into a realm of peatland, made from old vegetation—centuries worth of moss or reeds that grew here when this was a marsh.
Peatlands like this are surprisingly common and represent a wild card for the world's climate. They contain vast amounts of carbon, more than all the world's forests. They also are fragile. When drained, like Jörg Espig's field, they release carbon dioxide, accelerating climate change. Scientists are now calling for a global campaign to protect and restore these peatlands.
"Peatlands suffer from a Cinderella syndrome; they are often overlooked," says Franziska Tanneberger, who leads the Greifswald Mire Center at the University of Greifswald in Germany. Peatlands are found around the world, especially alongside streams and in coastal areas. They're common across northern Europe, the east coast of the U.S., Canada, Siberia, and many Pacific islands. They cover about 3% of the planet's land surface.
But these carbon vaults are vulnerable, as Espig's field demonstrates. The peatland section of this field is sunken. In some places, it's 3 feet lower than the regular mineral soil. The soil has vanished into the air.
The reason, in a word, is drainage. Many decades ago, this land was claimed for agriculture using techniques pioneered by Dutch experts. A system of drainage ditches, pumps, and dikes removed water from the land so farmers could graze cattle or drive tractors across it to harvest hay. "If that dike weren't there," Espig says, gesturing toward the earthen wall at the far end of the field, "this area in front of us would be covered with water."
But peatlands need water to survive. "In a natural peatland, the water is like a protective layer. Once you remove the water, it's no longer protected," Tanneberger says. Oxygen in the air reacts with the carbon-rich soil, breaking it down in a kind of slow-motion combustion, releasing carbon dioxide.
It's almost like burning coal, but it doesn't get the same attention, Tanneberger says. "If that would be, like, black smoke coming out of the soil, you would immediately see it, and you would say, 'Oh, you have to do something," she says. "But you do not see the CO2 that's emitted right now."
Those planet-warming emissions add up. An average acre of drained peatland releases about 12 tons of carbon dioxide every year, roughly the equivalent of driving 25,000 miles in a typical gas-powered car. When such soil is tilled and used to grow crops, as is often done, for instance, in a drained section of the Florida Everglades, the emissions—and the loss of soil—are even higher. In parts of the Everglades Agricultural Area, roughly six feet worth of carbon-rich soil has vaporized over the past century.
In the northeast German state of Mecklenburg-West Pomerania, which includes much of the Baltic coast, "a stunning fact for many people here, including farmers, is that the drained peatlands make up 40% of the total greenhouse gas emissions of our region," Tanneberger says. Peatlands account for roughly 7% of the total greenhouse emissions of Germany.
These emissions can be stopped. One of Tanneberger's favorite examples is a windswept section of the Baltic coast near the city of Greifswald. Thirty years ago, environmental advocates persuaded local authorities here to move the dikes back from the coast and turn off the pumps that were required to keep the land dry. Water has now returned to part of this peatland. The carbon dioxide releases have stopped. New wetland vegetation might actually start capturing carbon from the air and start storing it again in new layers of peat.
"This site gives me hope that it is possible that people jointly agree on making the peatlands wet again," Tanneberger says. "This is something that I'm really convinced, deep in my heart, that we need."
At the ongoing international climate summit in Baku, Azerbaijan, peatland experts will push for the "rewetting" of peatlands around the world that have been drained and the preservation of those that remain in a natural state. People who can't attend in person can visit a "Virtual Peatlands Pavilion" online. Tanneberger won't be there herself; she's stopped traveling by air, for the most part, in an effort to reduce fossil fuel use.
Almost all of Germany's peatlands have been drained. Returning water to that land is essential, Tanneberger says, to achieve the country's climate goals.
Yet it's politically difficult to reverse practices that have been in place for many decades. Much of that drained peatland is now owned by farmers who are using it as pasture or hay fields. Most of them want to keep that land dry.
"It's a matter of property," Espig says. "The farmer didn't buy this land to protect the climate. He bought it to earn his daily bread. And his daily bread is milking cows. Or grazing cows. Or making hay."
Tanneberger thinks there's a way to preserve both wetlands and agriculture. She has been carrying out research on ways that farmers could still use that land when it's wet. They could, for instance, use tractors that are built to navigate on wet soil, harvesting hay even from soggy fields. Even better, she says, they could grow traditional wetland crops, like reeds that are used to make thatched roofs.
Espig, who also chairs the farmers' association in this region, is skeptical. Farming in wet conditions, he says, is complicated, often impractical, and generally doesn't make economic sense.
But he does see room for compromise. Perhaps 10% of the area's drained peatlands, he says, are not very profitable to farm; they could be returned to nature without causing much disruption. Local authorities could organize land swaps, rewetting peatlands and compensating farmers with publicly owned land elsewhere. And many farmers would be open to a buyout because farming has generally been in decline in this area. "You have to offer the farmer an alternative, and then he'd be ready to take it," Espig says.
Germany has been a leader worldwide when it comes to making such deals. Federal and local governments have helped pay to rewet about 5,000 acres of peatlands per year. But that's only a tiny slice of what's needed, Tanneberger says.
Germany has set a goal of cutting its net greenhouse gas emissions to zero before 2050. Meeting that goal, Tanneberger says, would require rewetting more than 100,000 acres of peatland each year.
Dan Charles is a freelance writer in Washington, DC. He was a visiting journalist at the German Centre for Integrative Biodiversity Research in Leipzig during the summer of 2024.
