OTTAWA: The Supreme Court of Canada on Thursday upheld a national carbon tax that is the centrepiece of Prime Minister Justin Trudeau’s climate plan, rejecting a constitutional challenge by several provinces.

The federal government imposed the levy in 2019 in order to meet its obligations under the 2015 Paris climate agreement to cut greenhouse gas emissions by 30 percent by 2030, from 2005 levels.

Initially set at Can$20 (US$16) per tonne of emissions, the carbon pricing scheme — which applies to a range of fuels and sources of CO2 emissions — is to incrementally rise to Can$170 per tonne by the end of the decade. This would be equivalent to about 28 cents per liter of gasoline.

“Addressing climate change requires collective national and international action... because the harmful effects of GHGs (greenhouse gases) are, by their very nature, not confined by borders,” the court said in its decision. It found that the federal parliament “has jurisdiction to enact this law as a matter of national concern under the peace, order and good government clause of the constitution.”

Oil-rich Alberta and Saskatchewan provinces, as well as Ontario, rejected the federal backstop on their own carbon pricing schemes that don’t measure up to the federal minimum price on carbon.

Federal opposition leader Erin O’Toole, meanwhile, vowed this week to get rid of the national carbon tax if his Tories unseat Trudeau’s Liberals in the next election.