Supreme Court won’t hear province’s appeal in youth-led Ontario climate case

The Supreme Court of Canada is seen, Friday, June 16, 2023 in Ottawa. THE CANADIAN PRESS/Adrian Wyld

Canada’s top court has turned down Ontario’s request to weigh in on a major challenge to its climate plan brought by a group of young activists.

The Supreme Court of Canada’s decision means the challenge will instead be revived in an Ontario court.

Lawyers for the seven young people have argued Ontario’s 2018 decision to replace its climate target with a weaker one committed the province to dangerously high greenhouse gas levels, in a way that jeopardizes their right to life and forces them to bear the brunt of future climate impacts.

Their challenge was initially rejected but given fresh life by Ontario’s top court last year, which sent the case back to a trial judge for a new hearing.

Legal experts say the case could clarify whether governments in Canada have any constitutional obligation to protect Canadians from climate change.

The group is asking for a court to order that the Ontario government come up with a science-based target in line with Canada’s international climate commitments.

This report by The Canadian Press was first published May 1, 2025.