Supreme Court rules that federal Greenhouse Gas Pollution Pricing Act is constitutional

25 March 2021

Reference re Greenhouse Gas Pollution Pricing Act, 2021 SCC 11

On March 25, 2021, the Supreme Court of Canada released its decision in the Greenhouse Gas Pollution Pricing Act ("GGPPA") references, with the majority confirming that the federal carbon pricing backstop is constitutional.



Three provinces – Saskatchewan, Ontario and Alberta – challenged the constitutionality of the GGPPA by references to their respective Courts of Appeal. The majority of the Saskatchewan and Ontario Courts of Appeal concluded the GGPPA was constitutional, while the majority of the Alberta Court of Appeal concluded it was unconstitutional. The Supreme Court heard oral submissions on appeals from all three provincial decisions on September 22 and 23, 2020.

The Reference was heard by a full nine-judge panel. Six of the judges found that the GGPPA sets minimum national standards of greenhouse gas ("GHG") price stringency to reduce GHG emissions, and Parliament has jurisdiction to enact this law as a matter of national concern under the peace, order and good government ("POGG") clause of section 91 of the Constitution

Jennifer King, Michael Finley and Liane Langstaff of Gowling WLG's Environmental Group, assisted by Chris Hummel and student-at-law Graham Reeder, represented the intervenor Canadian Public Health Association ("CPHA") in the GGPPA references at the Supreme Court of Canada, and earlier before the Saskatchewan and Ontario Courts of Appeal.

Read our detailed case commentary.


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