Trevor Herriot is a Regina-based naturalist and the author of eight books including The Economy of Sparrows, released in September 2023.
If you live in Western Canada, you’ve seen it in your news feed: El Niño and climate change tag teaming to produce scant snowfall and warmer temperatures this winter; meteorologists and others predicting more forest fires, worsening drought and water shortages to come.
In January, Alberta announced in an online town hall meeting on drought readiness that it was preparing for a state of emergency. Fifty-one basins north to south were already experiencing a water shortage. People in the town of Cowley, Alta., and other nearby communities have been hauling drinking water since last July. Their water comes from the Oldman reservoir, but prolonged drought has left the intake pipes high and dry.
A few weeks ago, John Pomeroy, Canada Research Chair in Water Resources and Climate Change, was on The Big Story podcast, talking about drought.
The extent of last year’s drought “puts us in a precarious situation,” he said, “with very low soil moisture levels, reservoirs that have been depleted already and in some cases are five metres below normal levels.”
The low snowpack in the Rockies, which he called “the water towers that supply the rivers that flow into B.C., the Northwest Territories, Alberta, Saskatchewan and Manitoba,” will put this vast area of Canada into “great peril in 2024 for extreme hydrological drought — something unprecedented in modern times.”
East of the mountains, however, there is another, lesser known hydrological system that has been keeping part of the northern Great Plains hydrated, and helping it survive cycles of drought since the last ice sheets drew back and left a glaciated Serengeti of Pleistocene megafauna.
As chunks of ice calved off the front of the retreating glacier, they became buried in till and then melted away to form millions of pothole depressions that still dimple the plains from Iowa to the Peace Lowlands of northwestern Alberta — encompassing more than 770,000 square kilometres in one of the planet’s most diverse and unique wetland-grassland ecosystems.
This “prairie pothole region,” however, is also part of one of the most altered landscapes on Earth, having been converted to vast industrial farms growing corn, cereal, oil, hay and pulse crops.
It’s estimated that as much as 70 per cent of wetlands have been lost in settled areas of the Prairies. In certain regions of the prairies the number is in excess of 90 per cent. Last summer, the farmers trying to make a living on such a de-watered landscape watched their crops wither in drought. A record $2.4 billion in crop insurance payouts from the province ensued, which Saskatchewan’s finance minister used to explain a higher than forecasted deficit.
Just as outdated forestry practices intensified last summer’s forest fires, this is another place where the history of land management in Western Canada is bringing a new normal that will require new thinking.
“It makes me a little uncomfortable, but it’s been said before,” one of those thinkers, Pascal Badiou, says from his home in Winnipeg.
Badiou reluctantly admits he might be Canada’s leading expert on the climate solution values of wetlands. Over the phone, he sounds a bit like your favourite high school science teacher: someone who knows how to balance the limitations of his audience with the need to communicate the complexities of the thing that gets him out of bed each morning.
During the 45-minute conversation, those complexities reveal themselves one at a time, informed by his passion for the prairie pothole region as a unique landscape. There may be one or two other regions on the planet that have small wetlands like this, he says, but not over such a vast region.
Born and raised in the francophone St. Boniface neighbourhood of Winnipeg, Badiou had the science chops that might have made him a pharmacist, but early in his studies his girlfriend (now wife) brought him out on a canoe trip in Ontario’s Quetico Provincial Park. His life studying aquatic ecology starting there. He knew then, he says, that “these are the things I want to study for the rest of my life.”
As a leading research scientist at Ducks Unlimited Canada’s Institute for Wetland and Waterfowl Research, he focuses on how wetlands provide carbon and greenhouse gas services, as well as how wetlands contribute to water quality and quantity.
Research by Badiou and colleagues around the planet has shown that 30 per cent of terrestrial carbon on the planet is stored in wetlands, although they cover only seven per cent of the surface area. While the majority of that is stored in boreal peatlands, prairie potholes like the ones Badiou studies are believed to be taking up more carbon per hectare on an annual basis.
Everything in the greenhouse emissions arena, however, has at least two sides. The higher productivity of prairie wetlands means that, when mismanaged, they can emit more carbon as well as methane, Badiou says.
Studies that the institute has done across Manitoba, Saskatchewan and Alberta have shown the median nutrient concentration in wetlands surrounded by cropland is 40 times higher than levels in wetlands surrounded by grassland or woody vegetation.
“And, what we are seeing is that if you have higher nutrient concentrations in a wetland, you also have higher methane emissions,” Badiou says. That means natural wetlands on the prairies that were once helping to cool the climate both locally and globally can, under intensive agriculture, become greater sources of methane, which is much more potent than carbon as a greenhouse gas.
The institute measures carbon and methane emissions with something Badiou calls “Eddy covariance flux towers.” Mounted with sophisticated sensors for measuring GHG emissions, the instruments provide real-time results showing the amount of carbon entering and leaving the wetland.
Badiou believes if farmers were given an incentive to restore a buffer of some natural, perennial cover around each wetland, the nutrient load in the wetland might drop enough to allow it to become a sink instead of a source of greenhouse emissions.
Meanwhile, Badiou says, “smaller wetlands do a disproportionately better job of processing nutrients. It’s the same reason that small wetlands are more productive for all forms of aquatic life, including waterfowl. “Your perimeter to surface area ratio is much greater. The perimeter is where all the biological action is happening — nutrient processing, productivity and habitat.”
Unfortunately, farmers have been allowed to drain these smaller, more productive and ecologically valuable wetlands — classified by government water agencies as class one, two and three wetlands — often by consolidating them into larger permanent ponds.
That, Badiou says, is a bad idea. “If you drain all the small wetlands into these larger permanent ponds with little habitat surrounding them, they can become choked with blue-green algae blooms and that results in pretty big pulses of methane emissions.”
“Over the last half century, 488,000 hectares of wetlands have been destroyed in the region, releasing approximately 43 million tonnes of carbon [which is] equivalent to the emissions of approximately 1.5 million cars over 20 years.”
When asked about the local climate effects of de-watering large expanses of the prairie pothole region, Badiou says they are“really just embarking on that line of research and we are trying to generate some of the answers with our flux towers.”
The towers allow them to look at local temperatures, relative humidity, incoming and outgoing long-wave and short-wave radiation and evapotranspiration.
They are finding that wetlands provide a direct climate benefit. “Just like when you stand next to a lake on a hot day to get cool, that’s what this complement of prairie wetlands does. They’re air conditioners. They’re cooling and humidifying the atmosphere.”
He goes on to talk about the effects of heat stress on crops during prolonged drought, suggesting that these climate cooling effects are another reason to retain wetlands. He says he is “interested in seeing if there are improved crop yields when wetlands are retained, especially in times of drought. . . . Any time you’re able to keep water on the landscape you’re going to contribute to local precipitation as well as cooling.”
With all that in mind, what would he say to the public today, on World Wetlands Day?
“In the spring, get out and go visit a local wetland when you can. Just sit there for 10 or 15 minutes. If you take the time and just sit there and let yourself be a part of it, you cannot miss the sheer abundance of life. Look into the water column — it is teeming with life. I’m amazed every time I go. If people can generate that connection with nature in a wetland, they’ll realize their value.”
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