Peat is an accumulation of partially decayed vegetation or organic matter that is unique to natural areas called peatlands, bogs, or mires, and is the precursor to coal. The peatland ecosystem is the most efficient carbon sink on the planet because peatland plants capture the CO2 which is naturally released from the peat, thus maintaining an equilibrium. Healthy peat bogs can do more than act as a carbon sink, they can also help with wildfires.
Canada’s 185 billion tons of mossy wetlands across the country act as firebreaks, literally dampening the flames as they move across the landscape. But when dried, the peatlands are a tinderbox — and a new study says the latter is becoming more and more common as the climate warms.
“Fire risk is going to become greater,” says researcher Dr. Mike Waddington of McMaster University.
“It’ll burn more often, the area burned will increase, but most importantly is the severity of that burning.”
Peat fires are especially smoky. A 2010 peatland fire near Moscow was responsible for more than 3,000 deaths from poor air quality.
They can also burrow underground and re-emerge days or even months after appearing to have been put out.
Peatlands can be dried in a number of ways. When managed for forestry or for peat harvesting, they are often drained; however, they are also drying on their own as a result of climate change.
Peat is actually a precursor to low-grade coal, and can itself be burned as fuel. But fighting fires on peatland, paradoxically, can add fire risk. When left unburned over time, peat wetlands lose their fire resistance.
“If we suppress fire and don’t let these ecosystems burn, you will lose this super-moss, this moss that’s quite fire resistant,” says Waddington.
“These peatlands generally burn and generally recover fine. The key is that if you get these megafires, when either the peatland is drained or you get severe drying under climate change, where they become bigger issues.”
The cruel irony of burning peatland is that as the climate warms, it dries more bogs. Those bogs hold more carbon than the Amazon rainforest, and when they burn, they release that carbon, further accelerating their own drying.
But Waddington says the process is reversible.
“The good news from the research we’ve shown is we know how to mitigate this fire risk: restoring these peatlands,” he says.
“In the case where the peatlands have been managed for forestry, we can thin the trees, and we can re-wet the ecosystem….The key is to get these critical keystone moss species growing on the surface again.”