A recent Ontario court decision was decided against plaintiffs’ constitutional challenge to the province’s climate inaction, but left a door open for future Canadian climate lawsuits by acknowledging that the issue could legitimately be decided in court, a recent legal analysis concludes.

“Although the Applicants in Mathur were not successful in their Charter challenge, the Court was not entirely unsympathetic to their arguments,” say a team of five lawyers with Toronto-based law firm McCarthy Tétrault.

“The key takeaway from Mathur is the finding that the Charter issues raised by the applicants are justiciable—signalling that government climate action (or inaction, as the case may be) can be justiciable where specific state action or legislation is challenged.”

Justiciability is the ability for an issue to be resolved in a court of law. In Canadian law, legal cases can only be brought to court if the subject matter is “suitable for judicial determination,” and not purely political without a sufficient legal component. In those cases, the judicial branch would leave the issue to be resolved by the legislative or executive branch, explains law firm Osler, Hoskin & Harcourt LLP.

In the recent case, Mathur v. His Majesty the King in Right of Ontario, legal charity Ecojustice Canada represented seven young climate change activists in a constitutional challenge to legislation passed by the Ontario government. The activists said the legislation, which substantially weakened provincial emissions reduction targets from 37% below 1990 levels by the end of 2030 to 30% below 2005 levels by 2030, was unconstitutional. They contended the provincial action violated their right to life and security under Section 7 of the Canadian Charter of Rights and Freedoms, as well as the right of every individual to be considered equal under law under Section 15.

The plaintiffs said “Ontario’s youth and future populations” are disproportionately susceptible to climate change impacts compared to older generations, and so as young people they were distinctively—and unequally—affected by the legislative changes.

Past rulings have found climate-centred lawsuits not justiciable, and the Ontario government argued that this case should be ruled out as a largely political issue. But the court determined that it was suitable for judicial determination because the challenge addressed specific legislation and engaged the identified Charter rights. Neither the court nor the Ontario government disputed that climate change is caused by human actions, though the Ford government still relied on a known climate denier in its defence.

The court ultimately ruled against the youth plaintiffs and did not order the Ontario government to revise its climate change targets. Although their Section 7 rights were engaged by the legislation, the judge ruled that the applications did not show that the negative outcomes were contrary “to the principles of fundamental justice”.

The court acknowledged that young people are disproportionately affected by climate change, but said those impacts were caused by climate change itself rather than the legislative changes, and represented a “temporal distinction” rather than a distinction based on age. As a result, the court found that the climate target change did not violate Section 15 rights, ruling that “Section 15(1) of the Charter does not impose a positive obligation on the state to remedy social inequalities or enact remedial legislation.”

But “while the applicants were not successful in advancing their Charterclaims, the Court considered the Charter issues, lending the Charter challenge legitimacy,” McCarthy Tétrault writes. That made the outcome an important step for climate litigation by determining that climate issues can be justiciable, despite the unfavourable ruling.

Meanwhile, with Ecojustice planning to appeal the decision, the Mathur case may not be over. As that next step unfolds, the youth plaintiffs join “other climate cases that allege violations of the Charter that are currently under appeal, as well,” says Osler, Hoskin & Harcourt LLP.