How natural solutions could mitigate 78 megatonnes of greenhouse gas emissions by 2030

IN 2019, THE FEDERAL GOVERNMENT committed to invest $3 billion in natural climate solutions to cut greenhouse gas emissions as part of its fight against climate change. Those solutions, which Canadian Geographic highlighted in a series of infographics in 2020 (herehere and here), maximize carbon storage in forests, wetlands, grasslands and agricultural lands. They do so via actions, or “pathways,” that protect, restore or better manage those lands, while providing important “co-benefits” like preserved habitat, clean water and sustainable employment.

The government renewed its natural climate solutions’ commitment in the 2021 federal budget with an additional $200 million for its agricultural climate solutions program. But turning the full sweep of its pledge into effective action still hinges on one more key ingredient: data. Specifically, an accurate measure of each pathway’s GHG mitigation potential, and at what cost, based on Canada’s geography, climate and land cover.

A new peer-reviewed study, “Natural Climate Solutions for Canada,” published in Science Advances on June 4, 2021, has come up with those figures. And it’s good news. Natural climate solutions have a GHG emissions mitigation potential of 78 megatonnes, enough to help Canada reduce emissions equivalent to powering every single home in Canada for about three years or to cut current annual national emissions by 11 per cent by 2030.

“This research confirms that nature has a really big potential to help Canada reduce its greenhouse gas emissions in a very meaningful way,” says Amanda Reed, director of strategic partnerships at Nature United, a lead partner on the project.

Researchers from 16 organizations looked at 24 pathways — such as tree-planting, enhanced use of cover crops in agriculture and freshwater mineral wetland restoration. Somewhat surprisingly, given how much attention Canada’s forests get in emissions discussions, they found that agricultural pathways and others, such as avoiding conversion of grasslands, represent nearly half of the mitigation achievable by 2030 — and those strategies are also some of the most cost-effective.

PATHWAY POTENTIAL VARIES OVER TIME

The 2030 target is important to keep in mind while acting on the results, Reed notes, because the potential of different pathways varies over time. Those based in improved management provide the fastest return, for example, followed by protection and then restoration. But since Canada’s climate goals don’t stop at 2030 — the national target is to reach net-zero emissions by 2050 — policy makers can’t focus solely on the short term.

“We don’t want to be [sending a message] that you can pick and choose pathways,” says Reed. “Instead, the message we’re hoping to convey is that Canada needs to invest in all of them — to protect and manage and restore.”

Forest restoration is perhaps the best example. Planting trees today won’t save a lot of emissions by 2030, but its mitigation potential in 2050 is huge — provided we plant them now.

Another key point, Reed says, is that researchers took into account the economic importance of forestry and agriculture. As a result, none of the mitigation hinges on closing forestry operations or taking good farmland out of production. Coupled with the co-benefits associated with natural climate solutions, this means the findings should readily translate into realistic, actionable policies.

“Restoration and management have direct benefits for forests, farmers and ranchers. The protect strategies tend to have a lot of benefits for Indigenous communities as they are linked to their own sustainable development plans,” she says. Together, they “contribute near-term and long-term to the green recovery.”

This article originally appeared on CanadianGeographic.ca. Illustration: Mary Sanche/CanGeo

Details about the four mitigation pathways and potential of each habitat type
 
AGRICULTURAL LANDS
When agricultural improvements are heavily oriented toward better management, the payback is almost immediate and the cost relatively low. In some cases, such as enhanced use of cover crops, reduced tillage, and manure and nutrient management, improvements are focussed on the wider and more strategic application of known best practices.
ONE: Cover crops, such as winter cereal or rye, can mitigate a cumulative 244.5 megatonnes of GHGs from 2021-2050.
TWO: Nutrient management can mitigate a cumulative 153 megatonnes of GHGs from 2021-2050.
THREE: Reduced tillage can mitigate a cumulative 15.4 megatonnes of GHGs from 2021-2050.
 
WETLANDS
Wetland pathways involve protecting and restoring peatlands, mineral wetlands, salt marshes and even seagrass. These actions all bring significant co-benefits by enhancing water quality and protecting critical freshwater and marine habitats for wildlife.
ONE: Avoiding peatland conversion can mitigate a cumulative 146 megatonnes of GHGs from 2021-2050.
TWO: Avoiding the conversion of freshwater wetlands can mitigate a cumulative 61.5 megatonnes of GHGs from 2021-2050.
THREE: Avoiding seagrass loss combined with the restoration of seagrass beds can combine to mitigate a cumulative 4.2 megatonnes of GHGs from 2021-2050.
 
GRASSLANDS
Avoiding conversion of grasslands and an increased focus on restoration of riparian grasslands are the primary pathways in this category. While closely associated with agriculture in some areas, the mitigation potential for grasslands is calculated separately to avoid double counting. Because grasslands make up some of Canada’s rarest habitats, these actions have important co-benefits for rare birds, plants and other wildlife.
ONE: Avoiding the conversion of grasslands can mitigate a cumulative 200 megatonnes of GHGs from 2021-2050.
TWO: Riparian grassland restoration can mitigate a cumulative 14 megatonnes of GHGs from 2021-2050.
THREE: Conserving and restoring Canada’s grasslands can also benefit a range of rare and endangered species.
 
FORESTS
Pathways here apply to large areas of the country, both urban and rural, and include management, protection and restoration. The largest mitigation potential in the short term rests in avoiding forest conversion and improving forest management, but when projected to 2050, ongoing tree planting to restore forest cover has a significant impact.
ONE: Avoiding forest conversion can mitigate a cumulative 63.3 megatonnes of GHGs from 2021-2050.
TWO: Improved management can mitigate a cumulative 471.4 megatonnes of GHGs from 2021-2050.
THREE: Restored forest cover can mitigate a cumulative 242.7 megatonnes of GHGs from 2021-2050.