Can you guess how greenhouse gas emissions changed under Harper and Trudeau?

In the past, Canada’s emissions declines were usually linked to an economic downturn. Emissions declined under Stephen Harper, but mostly after the 2008 financial crisis, when the whole economy slowed down.

Justin Trudeau’s term saw another crisis, the COVID-19 pandemic, which sent Canada's emissions tumbling as people stayed home and industries slowed down.

However, while emissions climbed back to near pre-financial crisis levels under Harper, they did not return to pre-pandemic levels under Trudeau. The Liberal government said that showed their climate plan was working; emissions have declined, even as the economy grew in 2022 and 2023.

Experts say the policies behind the recent emissions decline include cleaner electricity production, regulations on methane emissions from the oil and gas industry and buildings becoming more energy efficient.

Despite that decline, oil production during Trudeau’s tenure was actually higher than under Harper — keeping with a long-term trend of growing investment in the industry over the past three decades. Trudeau’s government also finished building the Trans Mountain pipeline, which has boosted Canada's exports by increasing pipeline capacity to the West Coast.

Emissions from generating electricity declined under both Harper and Trudeau — one of Canada’s biggest climate successes — but a large part of the reductions was thanks to provincial action: Ontario completed phasing out its coal plants by 2014, and Alberta by 2024. Renewable hydro power drives electricity production in Canada, especially in provinces like B.C. and Quebec, both of which have large hydro projects. Ontario, meanwhile, relies heavily on nuclear, which does not emit carbon either.