The Cap and Trade Cancellation Act (CTCA) was enacted by the province of Ontario in 2018. It repealed the Climate Change Mitigation and Low-carbon Economy Act, which had set out an emission reduction target of 37% below 2005 levels by 2030 in the province. In the CTCA, Ontario implemented a revised target of 30% emissions reduction below 2005 levels by 2030.

Ecojustice assisted seven youth environmental activists in filing an application against Ontario contesting the constitutionality of the CTCA. The Applicants asserted that the revised target violated the rights of Ontario youth and future generations as protected by ss. 7 and 15 of the Canadian Charter of Rights and Freedoms by failing to adequately address the risks associated with climate change. The Applicants sought a declaration that the revised target was unconstitutional and an order compelling Ontario to establish a revised emissions target consistent with Ontario’s commitments under the Paris Agreement.

On April 15, 2020, Ontario filed a motion seeking the dismissal of the case on the basis that the claim was not justiciable. Justice Brown denied the motion. In September 2022, the lawsuit proceeded to a hearing on its merits. Justice Vermette found that although the Applicants’ claim was justiciable, there was no violation of the Applicants’ ss. 7 and 15 Charter rights.

The Applicants appealed to the Court of Appeal for Ontario. CLAIHR, jointly with the Center for International Environmental Law (CIEL), intervened to make three primary submissions:

• First, as repeatedly confirmed by the Supreme Court of Canada, international law (including international environmental law) should inform the interpretation of the content of Charter rights, including what constitutes state action depriving life and security of the person under s. 7 of the Charter.
• Second, given Canada’s international law obligations and commitments, Ontario’s setting of a greenhouse gas (GHG) reduction target constitutes state action that, if inadequate, may deprive life and security of the person under s. 7 of the Charter.
• Third, in assessing whether a deprivation of s. 7 rights caused by the setting of an inadequate GHG reduction target is so grossly disproportionate as to violate the principles of fundamental justice, the court must consider the impacts of that deprivation on the rights of youth and future generations, consistent with the principle of intergenerational equity in international law.

The Ontario Court of Appeal unanimously allowed the appeal, finding that the application judge erred in framing it as a pure “positive rights” claim. Because Ontario voluntarily enacted statutory targets under the CTCA, those targets and actions must comply with the Charter. The matter was sent back to the Superior Court for a new hearing and for the application judge to decide whether Ontario had breached ss. 7 and 15 of the Charter.

Following the Court of Appeal decision, Ontario applied for leave to the Supreme Court of Canada. The moving parties opposed the application and brought their own application for  leave to cross-appeal. On May 1, 2025, the Supreme Court denied both applications.

CLAIHR has been granted leave to intervene at the Ontario Superior Court of Justice where the proceeding was remitted back from the Ontario Court of Appeal to determine appropriate remedy and whether the GHG reduction target and plan were Charter compliant. 

CLAIHR thanks Vibhu Sharma and Nicolas M. Rouleau for their pro bono assistance on this matter.