Supreme Court hears arguments for and against ending the carbon tax

Lawyers representing the federal and some provincial governments made their cases before Canada's highest court today for keeping or killing the carbon tax — the cornerstone of the Trudeau government's climate agenda.

For the first hearing in the Supreme Court of Canada building since the pandemic began, all nine justices arrived wearing face masks. They spread out over two rows to maximize physical distancing, with Plexiglas barriers between their red seats.

Their first day back saw lively exchanges between justices and lawyers from all sides, who were pressed on three separate appeals from Ontario, Alberta and Saskatchewan, the three provinces challenging the national carbon policy on constitutional grounds. 

The question before the high court is whether Ottawa overstepped its authority by imposing a carbon pricing backstop in provinces that don't have mechanisms to curb greenhouse gas emissions that meet Parliament's standards.

The problem with the federal policy, said lawyer Mitch McAdam — who is acting for Saskatchewan — is the federal government is telling provinces like Saskatchewan how they ought to reduce their emissions.

"This legislation is an Ottawa-knows-best. It's a big brother type of legislation," McAdam said.

In 2019, the appeal courts in Saskatchewan and Ontario upheld the federal law. Alberta's Court of Appeal ruled it unconstitutional earlier this year.

The lawyers for Saskatchewan, Ontario and Alberta said the environment falls under provincial jurisdiction and greenhouse gas emissions continue to be monitored by provincial governments. 

'Pollutants without borders'

But federal lawyer Guy Pratte argued climate change is a national concern that's too big for any one province to tackle on its own.

"Greenhouse gases are pollutants without borders," Pratte said in his opening remarks.

Ottawa is making the argument that it has the constitutional responsibility to respond to the threat of climate change by implementing a national price on pollution — something that has been recommended by experts as an effective way to reduce emissions. 

Pratte told the high court the provinces have flexibility and substantial power to adopt the kind of carbon pricing systems they like, as long as they meet Ottawa's minimum standards.

But Justice Malcolm Rowe said the tax is a preference, not a necessity.

"There are various ways to control emissions and they don't all involve price," Rowe said.

Lawyer Joshua Hunter, representing Ontario, argued this point when he told the court the province already has reduced greenhouse gas emissions by 22 per cent through the closure of coal plants — something that didn't score the province any points under the federal carbon pricing policy.

Justice Rosalie Abella pushed back, pointing out that in the absence of that policy, provinces could choose not to act.

"They [provinces] don't have Plexiglas at their borders and the effect of not choosing to engage in strategies that are ultimately helpful to the rest of the country has enormous implications," Abella said. 

Debate over climate change as a national concern

Chief Justice Richard Wagner asked McAdam whether the threat of climate change should be considered when considering the limits of the federal government's powers in the Constitution.

"Science has evolved, things that happened, were present in 1867 are different today, and should we take somehow this context into consideration when we interpret the Constitution?" Wagner asked. 

McAdam said the "living tree" doctrine — the legal theory that the Constitution must be read in a broad and progressive manner to adapt to changing times — must be applied with great caution. 

"This isn't about pruning the tree or recognizing a new branch or a new leaf. This is about ripping the tree out by the roots and replacing it with a new tree," McAdam said.

Justice Michael Moldaver called that analogy a "gross overstatement" and asked McAdam why he does not see climate change as an overriding, critical concern.

Justice Suzanne Côté also touched on this point by asking McAdam what would happen if one province opted to do nothing about curbing emissions — which led to an uncomfortable exchange with the chief justice.

"That's federalism and that's democracy," McAdam said. "If it's an unpopular decision, then they have to go to the polls and face the electorate."

"Are you saying that a national concern does not exist in the Constitution?" Wagner replied.

"I think it is an illegitimate power," McAdam said.

"That would be contrary to all our jurisprudence," Wagner said.