The Quebec government is intervening before the Supreme Court in Saskatchewan's challenge to the federal carbon tax.

Quebec Premier François Legault said his government is in favour of carbon pricing, but it must be exclusively a provincial responsibility.

"For us, it is important to protect provincial jurisdiction," he said.

"I have been clear with the premiers of other provinces who are opposed for other reasons to this [federal] encroachment. We want to protect provincial jurisdiction to fight climate change."

Currently, the federal carbon tax applies only to New Brunswick, Ontario, Manitoba and Saskatchewan. In Alberta the tax would come into effect as of Jan. 1.

Quebec is not affected by the federal government's decision since it joined a carbon exchange with California several years ago.

Regardless, Quebec Justice Minister Sonia LeBel said it still crucial to intervene on this issue to reaffirm provincial jurisdiction over the fight against climate change.

"Our arguments will be different. But since the court of appeal decided that it was under exclusive federal jurisdiction, I think it is important for Quebec to reaffirm its position," she said.

"We have our own market."

Quebec Justice Minister Sonia LeBel says federal law technically places the carbon pricing system chosen by Quebec under federal supervision. (Jacques Boissinot/Canadian Press)

In the fall election campaign, Legault promised to be Prime Minister Justin Trudeau's ally in the fight against climate change.

When asked about this, Quebec's premier said, "Justin Trudeau and I both agree on putting a price on carbon, but there are many ways to do it, and I think it should be up to each province to decide how to do it."

Requiring carbon pricing to reduce emissions

Under the federal government's pan-Canadian climate framework, all provinces were required to come up with a method to price carbon in order to reduce climate-altering carbon emissions.

Provinces that failed to deliver their own carbon taxes or cap-and-trade plans became subject to the federal carbon tax backstop at a rate of $20 on every tonne of greenhouse gas emissions in 2019, rising by $10 each year to $50 a tonne by 2022.

Ontario and Saskatchewan have both launched legal challenges of the carbon backstop that failed in provincial courts. New Brunswick and Prince Edward Island are among those intervening in Saskatchewan's ongoing legal challenge.