Canada's highest court has given the green light to the Trudeau government's authority to put a price on carbon.
"The essential factual backdrop to these appeals is uncontested," Chief Justice Richard Wagner wrote for the majority. "Climate change is real. It is caused by greenhouse gas emissions resulting from human activities, and it poses a grave threat to humanity’s future. The only way to address the threat of climate change is to reduce greenhouse gas emissions."
He noted that rising greenhouse gas emissions, which warm the planet, go beyond provincial boundaries. According to the majority on the court, it's a matter of national concern under the constitution's "peace, order and good government" clause.
As a result, six of the nine judges agreed that the Greenhouse Gas Pollution Pricing Act should not be struck down.
Parliament passed the legislation in 2018 and took effect on January 1, 2019.
The federal law sets a minimum price on carbon emissions in provinces that didn't set a provincial price.
Justices Russell Brown and Malcolm Rowe dissented and a third justice, Suzanne Côté dissented in part, finding the act unconstitutional but agreeing that climate change was of national concern.
The attorney generals of Saskatchewan, Ontario, and Alberta sought to have the act declared unconstitutional.
B.C. argued in favour of the law. Intervenors included the cities of Vancouver, Richmond, Victoria, Nelson, and Rossland, as well as the District of Squamish.
Environmental and human rights groups, First Nations organizations, health associations, and many others were also listed as intervenors.