Canada’s carbon-storing peat digs up a climate conundrum

Every year, about 1.3 million metric tonnes of Canada’s peatlands are dug up for sale to farmers and gardeners. With every hectare lost, planet-warming carbon dioxide is released into the air.

Peat extraction was responsible for about 2.1 megatonnes of carbon dioxide equivalent emissions in 2021 — about as much as the yearly emissions from five gas-fired power plants, according to Environment Canada. That does not account for the emissions the extracted peat may have been able to capture.

While some experts say peat is the most sustainable way to support agriculture, others insist it’s time to stop releasing carbon and disturbing peatland ecosystems. Peatland soils contain more than 44 per cent of all the planet’s soil carbon, according to the International Union for the Conservation of Nature, despite only making up three per cent of the planet’s land surface. And while extracted peatlands can be regenerated, the process is laborious and takes years.

“(Peatlands) are one of the most carbon-rich ecosystems on the planet. Of course, it matters in terms of a climate change equation,” said Janet Sumner, executive director of the Wildlands League. “It's the very definition of insanity to be trying to make reductions in our emissions while continuing to mine the carbon in peat bogs.”

Peat is a muddy brown mass of mostly dead sphagnum moss and other organic matter found primarily in bogs and fens. The soil-like substance is saturated with water, preventing it from decaying and releasing globe-warming carbon dioxide into the air.

It is valuable to farmers for its ability to hold moisture and drain excess water, which makes it a popular soil component.

Peat extraction is a big business: Canada exported a total of $683.5 million of peat, including peat for soil, in 2022. When peat moss is mixed into soil, it helps the soil hold moisture and drain excess water.

University of Laval peat restoration researcher Mélina Guêné-Nanchen said most of that peat goes to fortify soil for farms in Canada and the U.S. — from which Canada imported about $2.7 billion worth of produce in 2021.

“It's mainly used not for gardening at home but for producing vegetables and fruit on a larger scale, like what we eat every day,” Guêné-Nanchen said.

It is possible to grow peat moss back, but it can take years before a restored peatland stops emitting carbon dioxide.

Guêné-Nanchen noted peat extractors fund projects to restore the peatlands. According to the United Nations environment program’s assessment on peatlands, the industry is a major funder of academic research into peatland restoration.

So far, Brandon University peatland researcher Peter Whittington said the fastest way to regrow peat is through the “moss layer transfer method.” To restore a drained or extracted peatland, a restorer can level the remaining peat in an area and redirect water systems to ensure the land is saturated with water.

Then, a thin layer of moss can be moved onto the decaying moss from an existing peatland. The moss is covered with straw mulch to create a humid environment and stop it from drying out. Whittington said if the method is used within four years of peat extraction, a peatland can become a carbon-accumulating ecosystem in up to 20 years.

If left alone, it could take more than a century before the peatlands recover.

That’s not fast enough, Sumner said. Canada needs its existing peatlands to keep absorbing and sealing away carbon to meet a countrywide deadline of net-zero greenhouse gas emissions by 2050, she added.

Carbon emissions aside, Sumner said peatland extraction also alters ecosystems. According to Environment Canada, about 37,000 hectares of peatlands have been drained to extract peat for horticulture. While that’s less than a per cent of Canada’s total, Sumner said extraction has already disturbed centuries of growth within those sites.

“Peatland extraction is getting away with a lot because it gets to claim that it's sustainable based on the fact that they're not looking at individual sites, but they're looking at the entirety of Canada's peatlands in the managed areas,” Sumner said.

She said she hopes Canada will follow the lead of the United Kingdom, where peat sales for private gardens will be banned from 2024.

“I would like to see it phased out,” she said. “So I think that what we need to be looking at is what are all the different ways in which we can replace peat.”

But Whittington said the agriculture industry has yet to find a sustainable large-scale alternative to peated soils.

At present, Whittington said, the best alternative is coconut coir, a soil-like substance made from coconut fibre. But coconuts don’t grow in Canada, and shipping coir from overseas also has a large emissions footprint. Plus, imported soil ingredients need to be treated to prevent the spread of pathogens.

“​​I would love to be peat-free and have a much better solution,” he said. “But I'm not convinced it's going to be coconut coir or some of these other systems just because of their greenhouse gas budgets.”

Instead of targeting peat extraction, Guêné-Nanchen said Canadians need to protect peatlands from mining, oil and gas, and development projects — the Ring of Fire mining project alone would result in emissions of up to 250 megatonnes of carbon, according to the United Nations assessment.

“This is not to say that the peat extraction for horticulture doesn't have an impact on peatlands. Of course, it has an impact,” Guêné-Nanchen said. “But you have to keep in mind that the peat horticultural industry is not really the main disturbance of peatland in Canada.”

Instead, according to the United Nations assessment, agriculture and mining are leading causes of peatland degradation in Canada.

Still, Guêné-Nanchen said the horticultural peat industry needs to continue to find ways to restore peat and minimize damage to peatlands, and other industries needed to step up to the task.

“We need the peat,” Guêné-Nachen said. “(Industry) needs to continue improving their responsible management approach and continue restoring the peatlands.”