Grasslands a carbon-capture colossus

Do the math: Take Alberta $15-per-tonne carbon tax and then look at how much carbon is stored in grasslands

The massive root systems of prairie grasses mean they can store up to 130 tonnes of carbon per hectare.
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If the Alberta government really wants to reduce greenhouse gas emissions in the province, it should start with an incentive for farmers to reduce annual cropping, says a rangeland management expert.

Ed Bork
Ed Bork

“There’s a pretty compelling case about why there should be a direct economic incentive for producers to maintain or even increase the amount of perennial coverage that they have,” said Ed Bork, a professor of rangeland ecology and management researcher at the University of Alberta.

“If we don’t put an economic incentive there for producers to retain and maintain and increase that resource, we’re at greater risk of losing it.”

Grasslands store up to 30 per cent of the world’s organic carbon, said Bork, who spoke at a drought management workshop hosted by the West-Central Forage Association last month.

“Temperate grasslands, like where we are, store more than 300 gigatonnes of carbon. Nine gigatonnes are basically in plants, while the majority is below ground in soil,” said Bork.

“That’s a huge pool of carbon.”

But as lands are converted from native grasslands to annual cropping, the carbon in the soil is released into the atmosphere as greenhouse gas.

“When people think about global warming, they only think about the burning of fossil fuels, but much of the carbon in the atmosphere is also attributed to land use change,” he said.

In a study looking at the carbon profile in both grasslands and annually cropped land, researchers found the total pool of carbon in the soil was significantly less in cropped land.

“In the Prairie region, we’re looking at a little over 80 tonnes per hectare of grassland, and under cropping, we’ve gone down to about 60 tonnes per hectare,” he said.

“We’ve lost about 25 to 30 per cent of that carbon back to the atmosphere.”

In the Parkland region, that number is bigger — a 40 to 45 per cent decline in carbon, at close to 130 tonnes per hectare on grasslands versus 70 tonnes for a hectare of cropland.

“All that carbon has been released by annual cropping.”

And Bork thinks that carbon should be worth something to producers who preserve it in the soil.

“I would argue that this represents a very significant benefit to society — that this carbon is being retained in the ground where it should be,” he said. “Of course, it contributes to fertility and plant growth, but it’s also not up there contributing to that greenhouse effect.”

The provincial government currently imposes a carbon tax of $15 a tonne per CO2 equivalent. That tax is set to increase to $20 a tonne in January 2017 and then to $30 a tonne a year later. Bork used those figures to calculate a dollar value for the carbon being protected in Alberta’s grasslands.

“In the Parkland region in a comparison with cropland, we are currently conserving about 65 million tonnes of carbon by maintaining that native grassland,” said Bork. “If you attach the $15-a-tonne value, that’s worth $3.56 billion. In 2018, that’s going to double to over $7 billion.”

Bork also looked at how much carbon has been lost because of cultivation.

“If you add up that area and assign the $15-per-tonne equivalent to the reduction in carbon, it’s 205 million tonnes of carbon, and that’s worth roughly $11.25 billion. In 2018, that will be worth over $22 billion,” he said.

“The question that I have for policy-makers and regulators is, ‘Why are we not valuing this carbon more right now?’ That frustrates me, and it probably frustrates a lot of farmers.”

But right now, it’s not worth it to producers to convert their cropland into grassland.

“I’m a big advocate for maintaining native grassland. We’ve taken some of our marginal land at home and put it into perennial forage,” said Bork.

“But I know that economics are going to drive everything. When you’ve got $12 canola, that’s going to drive a lot of this.”

A financial incentive for maintaining and even increasing grassland could change that, and help the Alberta government reduce greenhouse gas emissions.

“The more value we can put on these areas providing environmental goods and services, the greater the chance that we can maintain them and, where possible, convert marginal cropland to grassland,” said Bork.

“This all goes toward creating a business case for the government to create some innovative policy to reward producers for building up carbon and reducing greenhouse gases.”

About the author


Jennifer Blair

Jennifer Blair is a Red Deer-based reporter with a post-secondary education in professional writing and nearly 10 years of experience in corporate communications, policy development, and journalism. She's spent half of her career telling stories about an industry she loves for an audience she admires--the farmers who work every day to build a better agriculture industry in Alberta.



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