Constitutional Class Actions as a Tool to Address and Correct Environmental Wrongs

By Shirin Mollayeva, 3L, Lincoln Alexander School of Law

With a growing environmental consciousness around the world, it is no surprise that courts are having to grapple with the climate change crisis in litigation. Most such litigation alleges constitutional and human rights violations, negligence, fraud and deceit, among other causes of action, against corporations and governments. Most cases have originated in the United States and have been met with varying success in recent years.

With its generally inadequate performance on environmental report cards on account of its energy consumption and resultant high GHG emissions, poor air quality, and subpar response to these issues, Canada has also been the target of environmental litigation. Most such efforts have proven unsuccessful. As of October 2023, a total of 35 climate change cases have been filed in Canada, though as noted by Professor Jasminka Kalajdzic in Climate Change Class Actions in Canada, this number includes regressive actions challenging government imposition of environmental regulations and the carbon tax.

One of these 35 cases, ENVironnement JEUnesse v Procureur General du Canada, was a class action framed as a constitutional challenge that was unsuccessful at certification, a decision that was upheld on appeal. Despite their relative paucity and the outcome in that particular case, constitutional class actions may provide a potential alternative to address and correct systemic environmental wrongs in Canada, where, with the exception of Québec, there is no substantive legal right to a sustainable environment. Applications, for example, can be vulnerable to being struck when they do not plead the material facts on which the claim is founded, and multi-party actions may not adequately remedy mass wrongs or permit creative remedies, such as cy-près distributions.

First generation climate change litigation, including class actions, tended to involve causes of action in tort or breaches of environmental legislation, while second generation climate change cases are increasingly framed as human rights and constitutional violations brought against governments. Constitutional climate change class actions belong to this latter category and there is reason to believe that their certification is possible in Canada, paving the way for a systemic response to the climate change crisis.


Justiciability is an important consideration in all constitutional litigation. A matter is justiciable if the question brought before the court is not purely political and has a legal component, thereby respecting the separation of powers between the executive, legislative and judicial branches of government. The novelty of climate change as the subject of litigation and its inherent intersection with politics may complicate this, but Canadian rulings demonstrate that the courts are open to reviewing climate-related state action for its constitutional compliance. For example, in Mathur v Her Majesty the Queen in Right of Ontario, while the claims did not ultimately succeed, the court found that the issues raised by the applicants, seven youths, were generally justiciable because they were challenging specific state action and legislation. Engagement of the Charter meant there was a “sufficient legal component to warrant intervention of the judicial branch”. Further, jurisprudence from the Supreme Court of Canada suggests that judicial review of government conduct is not limited to action taken, but can also apply to inaction on the part of state, which is particularly relevant in the context of climate change.

The remedies sought by the plaintiffs will also impact the justiciability assessment. In La Rose v Her Majesty the Queen, the Federal Court found that the remedies sought, a declaration that the federal government’s approach to climate change breached the Charter and an order that it develop an enforceable response plan to be overseen by the court, were not justiciable. The court’s conclusion that such a remedy ran counter to the separation of powers has attracted criticism on the basis that it was open to the court to order declaratory relief. For example, the court could have outlined the existence and extent of relevant rights and obligations and left it to the government to respond accordingly. In Mathur, Justice Vermette noted that the declaratory relief sought was within the power of the court to grant.


The same rationale used to overcome the justiciability hurdle can be used to meet the first criterion of the certification test. To be certified, an action must disclose a cause of action; it must be “plain and obvious” that the action is not doomed to fail. The significant harms of climate change are widely acknowledged by the scientific community and are arguably sufficient to meet the “plain and obvious” test for the purpose of certification. The applicants in Mathur successfully resisted Ontario’s motion to strike. Justice Brown stated that because the impugned policies were at least quasi-legislative, they were justiciable. Moreover, the claims were capable of scientific proof and thus were not plainly and obviously doomed to fail.

The second certification criterion, an identifiable class, is generally not a difficult test to meet. While it was the basis on which the ENVironnement JEUnesse case failed certification (the issue was also determined to be non-justiciable by the Court of Appeal based on the declaratory relief sought), that case involved a cut-off of 35 years of age, which was found to be arbitrary given climate change affects the entire population. This conclusion, however, is brought into question by the fact that global warming is not stable and is projected to increase without effective intervention, leading to extreme environmental events that will disproportionately impact younger persons.  

Both Charter violations and climate change generally raise common issues. With Charter violations, the same conduct by the government can bring about the rights violations experienced by a large group of people. In the context of climate change, there is a baseline level of harm experienced by all those who are exposed.

The fourth element of the certification test requires the court to determine whether the class action is manageable and preferable to alternatives. The common issues in a climate change class action outweigh individual ones because at its core, the action addresses the impugned government conduct and its compliance with the Charter. And while defendants may argue a test case would be preferable given the novelty of climate change litigation, similar arguments have been successfully challenged by plaintiffs in the past on the basis that an individual case, while capable of addressing the question of constitutional validity, would not necessarily address the right of recovery where there may be thousands of claimants with nearly identical claims. Declaratory relief, together with an award of damages, is recognized to be a stronger means of achieving behaviour modification.

Finally, the availability of suitable representative plaintiffs to vigorously prosecute the action is not likely to pose a problem given the ardent climate advocacy taking place in Canada. This is evidenced by the growing number of environmental cases filed in the country over the years.


These arguments are not without their nuances, and recent case law reflects a very cautious judicial approach to climate litigation. Nevertheless, by learning from past failures, the constitutional class action remains a viable tool that combines the legal and practical benefits of class actions with the powerful nature of constitutional climate change litigation.

As noted by the Conference Board of Canada in its 2016 report on the country’s environmental performance, “a country must not only demonstrate a high quality of life – it must also demonstrate that its high quality of life is sustainable”. In a capitalist society where producers often operate according to a “move fast and break things” ideology, class actions present an accessible tool for vulnerable groups who are harmed in the process and who share a concern for the future generations that will bear the inevitable repercussions of climate change inaction. A rights-based approach does not wait for catastrophic injury to take place or rely on blatant violations of law to pursue corrective action. While legislative safeguards and more responsible consumption are important elements in the fight for a cleaner, more sustainable environment, as has been observed in constitutional climate change actions in other countries, the legal system is often an important precursor to change.

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