Landmark Ontario climate case lives on, but appeal court won’t revisit ruling

TORONTO — Ontario’s top court has declined to reopen its ruling in a landmark challenge of the provincial government’s climate plan, confirming the youth-led case should be sent back to a lower court.

The young activists had asked the Court of Appeal for Ontario to reopen the appeal, arguing Premier Doug Ford’s government gutted a 2018 climate law last year in a bid to avoid accountability on whether its weakened emissions target violated the Charter of Rights and Freedoms.

Today’s ruling rejected the request but leaves open the possibility that the case could continue despite the partial repeal of the law, leaving it with the Superior Court to decide. Almost seven years after it was launched, the Charter challenge remains unresolved.

The activists argued Ontario’s weakened 2018 target contributes to the threat posed by climate change to the lives and security of Ontarians and future generations, in violation of the Charter.

The Superior Court in 2023 found the target was “without an apparent scientific basis” but nonetheless dismissed the challenge, finding the activists were trying to impose a constitutional obligation to fight climate change on the province.

The following year, the appeal court ordered a new hearing in the lower court, ruling that Ontario had voluntarily assumed an obligation to fight climate change in the 2018 law.

Shortly before that new hearing was set to take place last year, the province scrapped key sections of the law requiring it to set a target and regularly update its climate plan.

At the time, the premier’s office suggested economic uncertainty and U.S. tariffs were part of the reason for the change.

The young activists argued it was an 11th-hour bid to shut down the case and evade accountability. The move also came weeks after an auditor general’s report found the province was set to miss its target by an even wider margin than it had previously reported and it had not released a new update to its climate plan since 2021.

It was the first case to be tried in Canada that considered whether a government’s climate-change approach has the potential to violate the Charter.

This report by The Canadian Press was first published Aug. 5, 2026.

Jordan Omstead, The Canadian Press