The largest herds of caribou in the world make their homes here. Polar bears give birth to cubs in dens dug into this soil, some of them more than 200 years old. And birds like the Arctic tern fly north every summer, some from as far south as Antarctica, to breed and lay their eggs.
The Hudson Bay peatlands in northern Canada, a 90-million-acre area stretching from northern Manitoba to Quebec, are a haven for biodiversity, home to more than 1,000 species of plants and 175 species of birds. But the secret of this unique ecosyste…
The largest herds of caribou in the world make their homes here. Polar bears give birth to cubs in dens dug into this soil, some of them more than 200 years old. And birds like the Arctic tern fly north every summer, some from as far south as Antarctica, to breed and lay their eggs.
The Hudson Bay peatlands in northern Canada, a 90-million-acre area stretching from northern Manitoba to Quebec, are a haven for biodiversity, home to more than 1,000 species of plants and 175 species of birds. But the secret of this unique ecosystem lies below the surface, in a buildup of water-saturated mosses called peat.
This story was originally published by Vox and is reproduced here as part of the Climate Desk collaboration.
Though it looks like little more than fibrous dirt, peat has near-magical properties.
Acidic and anaerobic, it can preserve artifacts, food, and even human remains for centuries or more. And because the process of decomposition slows down in such environments, they trap carbon dioxide and keep it out of the atmosphere, slowing the process of climate change.
The Hudson Bay peatlands in particular store five times as much carbon per acre as the Amazon rainforest, Janet Sumner, executive director of the Wildlands League, a Canadian conservation group, said. Indigenous nations around Hudson Bay call the area “the breathing lands.”
“It’s the world’s temperature regulator,” said Valérie Courtois, executive director of the Indigenous Leadership Initiative, which works on Indigenous-led conservation efforts in Canada. “It’s like we have a big fridge on top of the planet that is helping keep everything the way that it should be.”
But now, the fridge is hanging open.
Though they cover only 3 percent of the Earth’s surface, peatlands store nearly one-third of the world’s carbon. And these ecosystems around the world are vulnerable to development and destruction. Today, only 17 percent of the world’s peatlands fall within a protected area, according to a recent study by the Wildlife Conservation Society.
The world’s peatlands are increasingly at the center of conflicts over resource extraction, and the stakes couldn’t be higher.
In northern Canada, one of the biggest fears for peat conservationists is mining for rare-earth minerals. Part of the Hudson Bay peatland sits atop the Ring of Fire, a mineral deposit containing nickel, chromium, and other metals used in clean energy technologies like electric vehicle batteries. Some experts see the minerals there as key to Canada’s clean-energy transition and a crucial part of the fight against climate change. And it’s true; minerals like the ones found around Hudson Bay are necessary for solar panels, batteries, and other technologies we need to reduce our dependence on fossil fuels.
But in the process of mining them, we may just destroy a crucial climate regulator.
The government of Ontario, where the Ring of Fire is located, sees mining in the area as necessary for Canadian energy independence, especially amid President Donald Trump’s trade wars. “This is how we make ourselves less reliant on the United States,” Ontario Premier Doug Ford said this summer.
“These are the lungs of the Earth,” Martin said. “If you start tampering with that, you have to be really, really careful.”
And already, the area’s peatlands are at risk from mining expeditions, which experts say have disturbed the ecosystem even though no mineshafts have yet been sunk. First Nations and conservation groups are working to protect the lands around Hudson Bay, but it’s a race against the clock as mining exploration ramps up with support from the Canadian government.
The carbon stored in the Hudson Bay peatlands took thousands of years to build up, said Lawrence Martin, director of lands and resources for the Mushgewok Council, a group representing several First Nations in the area. If it’s released now, it could take thousands of years to replace. And if humans want to avoid the worst effects of climate change, we don’t have that kind of time.
“These are the lungs of the Earth,” Martin said. “If you start tampering with that, you have to be really, really careful.”
Peat is a kind of soil that forms whenever organic matter builds up faster than it can decompose, said Dan Zarin, executive director for forests and climate change at the Wildlife Conservation Society. The bogs of northern Europe, famous resting places for uncannily preserved bog bodies, are made of peat. But peat can also be found in the United States, in the Adirondacks of upstate New York and the huge Okefenokee Swamp in Georgia.
The soil also forms in the tropics, often in damp, forested areas where layers of different plant species stack on top of one another. In Panama, for example, peat can form giant domes, several meters deep and thousands of years old.
Peat is a kind of soil that forms whenever organic matter builds up faster than it can decompose.
Visual: Anna North/Vox
In colder climates like northern Canada, peatlands are usually created by colonies of sphagnum moss — a simple, easily overlooked plant that’s also a climate hero.
The structure of sphagnum includes large, empty cells that make the plant into a kind of sponge, absorbing up to 20 times its weight in water. Moss was so well-known for its absorbent properties that First Nations peoples once used it for menstrual products and diapers, Courtois said. That absorbency helps create the wet, low-oxygen conditions that slow down decomposition and aid in carbon capture.
There’s more carbon stored in peatlands than in all the trees in the world — or about two-third of the world’s petroleum reserves — Zarin said. The peatlands in the Congo Basin store the equivalent of several years’ worth of carbon emissions for the entire world. That’s why peat is so critical to the world’s climate future, Zarin said, and yet, “it’s not really getting anything near the attention it deserves.”
Around the world, ecosystems like tropical forests and mangroves are much more likely to be protected than peatlands, according to the Wildlife Conservation Society. And nearly a quarter of peatlands are under heavy pressure from human development.
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In Indonesia, for example, forested peatlands are being cleared, drained, and planted with palms to feed the rapidly growing global demand for palm oil, a common ingredient in products from toothpaste to peanut butter. In Patagonia, they’re threatened by urban development, said Jorge Hoyos-Santillán, a research associate at the Smithsonian Tropical Research Institute in Panama. Around the world, peat is harvested and sold for use in potting soil — an 8-quart bag retails for less than $10 at U.S. hardware stores, where Americans can purchase it for their berry patches and flower beds.
And now, increasingly, peatlands are at risk, as governments and private industry seek new sources of the minerals needed for the batteries and related technologies that will likely power the world in the future.
Around Hudson Bay, conservation groups are watching with concern as mining companies begin to survey fragile wetland ecosystems. “People focus on the mining, but there’s a lot of damage that occurs before mining,” Sumner of the Wildlands League said.
Mining exploration requires test drilling and the use of heavy machinery on a sensitive landscape, which can change its hydrology, causing areas of peatland to dry out, Sumner said.
When peat dries out, its carbon-storing superpower becomes a liability.
As water leaves the environment, decomposition starts again, and the soil begins to release all the carbon it’s stored up over thousands of years. You can think of it like the burning of fossil fuels, said Julie Loisel, a professor of geography at the University of Nevada, Reno. “It took a long time to put that carbon down into the soil, and then you really quickly release it back to the atmosphere.”
Peatland fires can release 100 times the carbon of a wildfire and produce large amounts of noxious smoke.
Drying peat also turns it into a frighteningly powerful fuel for fires — in fact, communities in Ireland and elsewhere have long burned peat as an alternative to coal. Today, peatland fires can be especially insidious, because even when they appear to be extinguished, they can continue to burn underground for months and re-spark — a phenomenon known as a “zombie fire.”
Peatland fires can release 100 times the carbon of a wildfire and produce large amounts of noxious smoke. In Indonesia in the 2010s, peat fires released as much carbon in a single day as the entire emissions of the United States, Zarin of the Wildlife Conservation Society said. Fires are already burning in the peatlands of northern Canada, spurred on by climate change, and experts fear they’ll only become more devastating if the landscape isn’t protected.
And now, research indicates we may have entered a new age of fire — where massive blazes around the world will be more frequent and destructive. It’s even more urgent to prevent peatlands from drying out and becoming fuel for these conflagrations.
“We want to keep the peatlands doing what they do, which is breathing for the planet,” Sumner said.
The carbon calculus involved in trading peatlands for EV batteries is a complicated one.
But conservation groups say mining in Canada’s Ring of Fire is less important for the clean energy transition than proponents have claimed. One issue is the remoteness of the area: The mining sites are currently accessible only by ice-road or float-plane, and a plan to build a major road to the area could take a decade, Sumner, of the Wildlands League, said.
Other sites in Ontario have more critical minerals, are more accessible, and are located in areas that are already environmentally degraded, Sumner said. Mining in the Ring of Fire “feels more like a dream than it does a reality, and it’s not going to meet the need for energy transition in any short timeline, which is what we need,” Sumner said.
Meanwhile, First Nations have been at work for years on their own plans for the Hudson Bay lowlands. The Mushkegowuk Council is leading an effort to establish an Indigenous-led conservation project in northern Ontario that could protect peatlands and other ecosystems, as well. The Kitchenuhmaykoosib Inninuwug First Nation has also proposed a protected area including peatlands around the Fawn River in northern Ontario.
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“What makes an Indigenous approach to planning is that you look at what you need to keep in those ecosystems as opposed to looking at what you can take,” Courtois of the Indigenous Leadership Initiative said. Under such an approach, Indigenous leaders can also identify less vulnerable areas where activities like mining could occur.
“The more that provinces embrace the practice of land use planning — or land relationship planning as we like to call it — the better the conditions are for the exploration of potential development,” Courtois said.
Representatives of the Mushkegowuk Council have also said mining could potentially coexist with conservation. “You do need to reach into the ground to pull out the resources necessary to keep us fed,” the Council’s Martin said. “But we need to do this with great conscience.”
The fate of the conservation project remains unclear, however, and Martin says the Council is still working to get the Ontario government on board.
Meanwhile, peatlands around the world remain at risk, as lack of knowledge and political will collide with economic development. In some parts of the world, they’ve “been treated as wasteland areas,” Zarin said. Indeed, the swampy bogs of the global north are a common setting for horror stories, seen as a place humans should avoid and fear.
“You do need to reach into the ground to pull out the resources necessary to keep us fed. But we need to do this with great conscience.”
The first step toward changing that is a better understanding of peatlands, experts say. These ecosystems are often in remote locations that are difficult for humans to navigate, and since peat lies beneath the surface, it’s often invisible even to researchers. The peatlands in the Congo Basin, for example, were only documented by scientists in the 2010s, and their full size — as big as England and Wales combined — was revealed only in 2023. Those discoveries have helped drive funding and conservation efforts to the area, said Hoyos-Santillán, from the Smithsonian Tropical Research Institute.
Beyond understanding, people around the world need an appreciation of peatlands and their value, conservationists say. “My hope is that the province of Ontario and other places that have these sorts of landscapes look at them not just as some sort of breadbasket for the development of the province, but also see it as a feature of who they are,” Courtois said.
“You can’t destroy everything for capitalism,” Martin said. “You have to be able to save enough for your children, for your future generations, for them to enjoy life.”
Anna North is a senior correspondent for Vox, where she covers American family life, work, and education.