Canada has a quarter of world's soil carbon. Keeping it in the ground could curb climate change, experts say
CBC
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Canada stores about a quarter of the world's soil carbon, according to a new study that puts a spotlight on the country's role in protecting that carbon to help prevent further climate change.
Those carbon-rich soils are found especially in peatland: boggy wetlands in northern Ontario and parts of Manitoba that are filled with accumulated plant matter that's been collecting over thousands of years.
Soil carbon is a valuable resource because it prevents greenhouse gases from entering the atmosphere, which is why it's so important to keep it in the ground. If this amount of carbon is lost — due to natural events, such as forest fires, or human activities, such as mining, logging and agriculture — it will end up in the atmosphere and exacerbate global warming, scientists say.
The study, released Wednesday at the COP26 climate change conference in Glasgow, suggests protecting this carbon is key to Canada's climate efforts. Keeping a 1.5 C limit on global warming "within reach" is one of the key goals of COP26, the annual meeting of the Conference of Parties, the global decision-making body set up in the 1990s to implement the United Nations Framework Convention on Climate Change and subsequent climate agreements.
"Ecosystem carbon storage and ensuring the avoided conversion and degradation of those important carbon stores can be a critical pathway to getting a 1.5 C future, making sure that carbon is not emitted into the atmosphere and, in turn, trying to grow the amount of carbon we're storing in these terrestrial ecosystems," said James Snider, who leads the science, knowledge and innovation team at World Wildlife Fund-Canada, which did the study in partnership with Hamilton's McMaster University.
Soil carbon is essentially the remains of plants in the soil — or the carbon dioxide the plants sucked out of the atmosphere when they were alive, now deposited into the soil — which is why it is especially found in peatland, which has layers of plant material.
Canada has so much soil carbon — 384 billion tonnes — because of the presence of so much peatland and because of its sheer size.
About five per cent of Canada's terrestrial carbon is stored in plants, trees, shrubs and other greenery above ground, the study found, while about 95 per cent of it is underground — in the top metre of soil.
The findings put a renewed focus on Canada's conservation efforts. The federal government has committed to protecting or conserving 25 per cent of Canada's land by 2025 and working toward protecting 30 per cent by 2030 as part of the country's efforts to fight climate change and defend vulnerable species and ecosystems.
"Canada has a tremendous responsibility globally in terms of stewarding and of protecting that ecosystem carbon," Snider said. "It's not only important to us ... it's important on a global scale, in terms of showing how a country like Canada can in fact still protect these places in the right way."
The study includes a detailed map of where the carbon is stored in Canada, all the way down to a resolution of 250 metres. This could make it possible for organizations, governments and even individuals to zoom in on certain areas and determine how carbon rich an ecosystem is — and how important it might be to protect it.
The study combined on-the-ground surveys and measurements with satellite technology and a machine learning algorithm to come up with the first accounting of the total carbon stores in Canada's ecosystems. Some of the techniques represent recent advances in technology that have not been available to researchers in the past.