Canada: Tree Planting Could Remove 5x Annual Emissions, Study Finds

Canada could significantly reduce its carbon footprint through large-scale reforestation efforts, according to a new study published in Communications Earth & Environment on November 13, 2025. The research suggests that planting trees along the northern edge of the country’s boreal forest could remove more than five times Canada’s annual carbon emissions by the end of the century.

The study, led by Kevin Dsouza, a postdoctoral researcher at the University of Waterloo, examined the potential for reforestation in the taiga area – the transitional zone between the boreal forest and the Arctic tundra. This area is experiencing a northward shift in forest composition due to climate change, presenting an opportunity to enhance carbon sequestration.

Researchers utilized satellite data to identify suitable land for reforestation, approximately 6.4 million hectares (15.8 million acres) – an area roughly twice the size of Vancouver Island. Simulations, incorporating factors like fire probabilities, climate variables, seedling mortality, and land type, estimated that planting trees on this land could remove almost 4 gigatons of carbon from the atmosphere by 2100. This figure represents about five times Canada’s current annual emissions. Dsouza noted that this 6.4 million hectare estimate is conservative, and expanding reforestation to 32 million hectares (79 million acres) could sequester nearly 20 gigatons of carbon.

The concept of using trees to combat climate change isn’t new. Canada previously launched an ambitious plan to plant 2 billion trees by 2031, but the program was canceled last year. As of June 2025, approximately 228 million trees had been planted, with agreements in place for an additional 988 million trees across the country.

Dsouza explained that the previous plan encountered logistical and funding challenges, rather than scientific flaws. “It wasn’t planned well, just trying to hit a number is not the right strategy,” he said. “It needs to be more strategic, planting in the right places, with economic and community benefits so It’s sustainable.”

Beyond carbon sequestration, reforestation in northern regions could help stabilize permafrost. Thawing permafrost releases methane, a greenhouse gas significantly more potent than carbon dioxide, potentially exacerbating climate change. Protecting permafrost is therefore a crucial consideration in climate mitigation strategies.

Longer-Term Thinking Needed

While reforestation offers a promising avenue for carbon removal, some experts advocate for a more nuanced approach. Ulf Büntgen, professor of Environmental Systems Analysis at the University of Cambridge, cautioned that planting trees is a short-term solution. He emphasized the importance of considering the long-term fate of the stored carbon.

“Planting trees is good but it’s not solving anything, it’s just buying time,” Büntgen said. “While the tree is growing it helps, but eventually it will die and release the carbon again.”

Büntgen and his colleagues recently proposed an alternative strategy in a study published in NPJ Climate Action on January 3, 2026. Their research suggests harvesting large, mature trees from specific areas of the boreal forest – those most vulnerable to fire and less efficient at carbon storage – and sinking them in the deep Arctic Ocean. The cold, oxygen-poor environment would preserve the trees and their carbon content for millennia. The harvested areas could then be replanted with younger trees, restarting the carbon capture cycle.

The team estimates that managing just 1% of the boreal forest in this manner could remove 1 gigaton of carbon dioxide from the atmosphere annually. “There’s already a lot of carbon in the timber that naturally finds its way to the ocean,” Büntgen explained. “We could accelerate this natural process.”