Ontario youth climate case to be put to the test again in December

Protesters take part in a climate protest march in Ottawa, on Sept. 21, 2024. THE CANADIAN PRESS/Spencer Colby

Ontario’s climate plan is set to be put to the constitutional test again in December.

A lawyer for a group of young climate activists says their historic constitutional challenge is set to be heard for a second time in Ontario Superior Court on Dec. 1 and 2.

The new hearing comes after Canada’s top court dismissed the province’s request that it weigh in on the case.

Lawyers for the group have argued Ontario’s 2018 decision to replace its climate target with a weaker one committed the province to dangerously high levels of greenhouse gases in violation of their Charter rights.

After the first full hearing in 2022, an Ontario Superior Court judge agreed the target fell “severely short of the scientific consensus” of sufficient action but ultimately ruled it wasn’t a violation of the constitution.

But on appeal, Ontario’s highest court issued a favourable ruling for the young climate activists and sent the case back to the lower court for another hearing.

This report by The Canadian Press was first published Aug. 12, 2025.

Jordan Omstead, The Canadian Press