The Supreme Court of Canada will hear a federal appeal this week trying to push through what’s often called the “No More Pipelines Act.”

The bill, C-69, is officially called the 2019 Impact Assessment Act (IAA), though former Alberta Premier Jason Kenney gave it its other monicker. It gives the federal government more power over approval for energy projects, in part, based on the government’s assessment of impacts related to greenhouse gas emissions.

Kenney called it a “federal sucker punch” and a “disaster for Alberta’s economy” before launching a legal fight against it.

It became law in June 2019, but in May 2022 Alberta’s top court said it was unconstitutional. Though that decision was not binding on the federal government, the federal government announced an appeal to the Supreme Court in July 2022. Canada’s top court is set to hear that appeal this week.

The Alberta Court of Appeal’s decision called the legislation an “existential threat” to provincial sovereignty. It decried “the clear and present danger this legislative scheme presents to the division of powers guaranteed by our constitution and thus, to Canada itself.”

It said environmental protection is important, but “the ‘environment’ is not a head of power assigned to either Parliament or provincial Legislatures.”

Dwight Newman, a law professor at the University of Saskatchewan, says the Alberta court’s strong support of federalism may not be reflected in other courts.

“Other courts are approaching federalism in Canada a little bit differently today, and the Alberta Court of Appeal may have a different approach than some other courts,” Newman said at a webinar hosted by the Macdonald-Laurier Institute following the court’s decision last year.

“I wouldn’t describe it so much in terms of the Alberta Court of Appeal standing for provincial rights, so much as the Alberta Court of Appeal standing for a very principled approach to federalism in line with a lot of prior jurisprudence.”

The Alberta court had called climate change an “existential threat,” but balanced it in the same paragraph against the “existential threat” to the division of powers in Canada.

The Supreme Court’s previous take on the urgency of climate change may auger its decision this time, natural resources lawyer David Wright told the CBC when the appeal was announced last year. The Supreme Court came to a split 6–3 decision upholding the Liberals’ carbon tax regime, with judges citing the urgency of climate change.

“Those are the best tea leaves we have and they would suggest … the majority opinion finding the federal impact assessment act as constitutional,” Wright said.

Opponents, including Kenney, have said the bill has already created uncertainty in the energy industry. In February 2020, Teck Resources Ltd. cancelled a $20.6 billion oilsands project, citing concern over the debates in Canada regarding resource development versus climate change.