Three provincial appellants challenged the constitutionality of the federal Greenhouse Gas Pollution Pricing Act, which established minimum national standards of greenhouse gas price stringency operating as a backstop to provincial pricing systems.
The courts below were divided, with the Saskatchewan and Ontario Courts of Appeal upholding the Act while the Alberta Court of Appeal struck it down.
A 6-3 majority of the Supreme Court held that the Act's pith and substance is the establishment of minimum national standards of greenhouse gas price stringency to reduce greenhouse gas emissions, and that this matter falls within Parliament's jurisdiction under the national concern branch of the peace, order, and good government power.
The majority further held that the fuel and excess emissions charges are constitutionally valid regulatory charges rather than taxes.
The appeals by the Attorneys General of Saskatchewan and Ontario were dismissed and the appeal by the Attorney General of British Columbia was allowed, with Côté J. dissenting in part and Brown and Rowe JJ. fully dissenting.