CALGARY -- In a 4-1 decision released Monday afternoon, the Alberta Court of Appeal ruled the federal carbon tax "substantially override(s) the provinces' powers," and "are unconstitutional in their entirety."

“This is a great victory for Alberta and a victory for Canadian federalism," declared Premier Jason Kenney shortly after the decision was released.

Lawyers for Ottawa argued its power to impose carbon pricing on the provinces is an extension of the federal government’s right to sign international treaties and to maintain powers necessary for peace, order and good government.

But the court differed, with the majority writing that, "If the federal government can successfully invoke the national concern doctrine because a province fails to see a policy issue the same way it does, then the federal government could effectively upend the election in any province or territory."

Both Ontario and Saskatchewan have lost similar challenges in the past year, with their appeals scheduled to be heard by the Supreme Court of Canada next month.

Climate groups were disappointed with the decision, saying it’s a step backward and puts a greater burden on jurisdictions attempting to act.

"If one province does less than the other, every other province feels the impact and other provinces need to pick up the slack toward meeting our emissions reduction target," said Isabelle Turcotte, director of federal policy at the Pembina Institute.

The court did not weigh in on the merits of climate action but urged reasoned discussion of the issues.

“While we have given our opinion on the validity of this Act, we cannot participate in the frank conversation across differences that is clearly called for in this country,” wrote three of the Justices.

“Tackling climate change, including reducing GHG emissions, is not an abstract concept nor an exercise in virtue seeking. As with everything in life, meeting the challenges of climate change while sustaining the economy is all about balance.”