On February 24, 2020 the Court of Appeal of Alberta found Canada's carbon pricing act unconstitutional. The court reasoned that the act was not a proper exercise of the national government's authority.
Alberta filed suit in June 2019, arguing that the Greenhouse Gas Pollution Pricing Act, SC 2018, c. 12 (the Act) was unconstitutional because it does not fall within the national concern branch of the Parliament's peace, order and good government (POGG) power. The Act imposes a price on greenhouse gases by establishing a "fuel charge" on 22 greenhouse gas-emitting fuels, and an out-put based pricing system for industrial emitters.
Ontario, New Brunswick, Saskatchewan, Saskatchewan Power Corporation and SaskEnergy, Inc, intervened in support of Alberta’s position. They contended that the “matter” of the Act is properly understood to be the regulation of greenhouse gas emissions, and that to give the federal government exclusive authority over such a matter under the national concern doctrine would unduly intrude into the provinces’ jurisdiction to regulate their own natural resources. Canada responded that it had the authority to enact the Act under the national concern doctrine, arguing that the Act's "matter" was in truth "the establishment of minimal national standards of stringency for GHG emissions pricing to reduce Canada's nationwide GHG emissions." British Columbia and three nonprofits intervened to support Canada.
The court ruled for Alberta, concluding that the Act does not fall within the Canadian government's authority under the national concern doctrine. The court explained that the government cannot use the national concern doctrine to commandeer matters assigned exclusively to the provinces. Ultimately, the court determined that the “matter” of the Act is properly construed as the “regulation of greenhouse gas emissions," and the Act therefore interferes with provincial jurisdiction over natural resources, property and civil rights, local works and undertakings, and direct taxation.