Developing Decisions: Environmental and Aboriginal Law Cases to Watch

Recent cases from Ontario, British Columbia, and the federal courts demonstrate a continuing trend in relying on constitutional law to hold governments to account for environmental harm and the impacts of industrial development. From relying on the Canadian Charter of Rights and Freedoms (Charter) to using the United Nations Declaration on the Rights of Indigenous Peoples[i] (UNDRIP) to interpret the duty to consult and accommodate pursuant to section 35 of the Constitution Act, 1982, these decisions have the potential to reshape the Canadian legal landscape in environmental and Aboriginal law. The following cases are decisions to watch for in the coming months.

Charter Cases and the Positive and Negative Rights Dichotomy

Mathur v His Majesty the King in Right of Ontario

In Mathur v His Majesty the King in Right of Ontario,[ii] seven young Ontarians challenged the Ontario government’s greenhouse gas reduction target established under climate change legislation for violating their sections 7 and 15 rights under the Charter. In particular, the applicants were concerned that Ontario’s new greenhouse gas emission target was significantly weaker than the previous target. The new target fell below the international scientific consensus of the reduction necessary to mitigate the catastrophic effects of climate change.[iii]

The application judge determined that it was “undisputable that, as a result of climate change, the Applicants and Ontarians … are experiencing an increased risk of death and an increased risk to security of the person.”[iv] Nevertheless, she dismissed the case as she found that the applicants were advancing a “positive rights” claim, which, to date, has not been recognized under section 7 of the Charter.[v]

The Court of Appeal for Ontario reversed the decision and determined that the matter was not a positive rights case.[vi] Instead, the Court unanimously found that since Ontario had voluntarily assumed a statutory obligation to combat climate change, it had to ensure it was Charter compliant. The Court, therefore, remanded the case for a new hearing. Ontario’s subsequent request to appeal the case to the Supreme Court of Canada was dismissed.[vii]

The case was set to be heard at the Superior Court of Justice in December 2025. However, a few days before the hearing, the Ontario government enacted legislative amendments that removed the requirement to set greenhouse gas emission reduction targets. The applicants, therefore, asked that the hearing be adjourned.

Subsequently, the applicants brought a motion to have the Court of Appeal reopen their previous appeal in light of the legislative repeal and resolve the issue as to whether Ontario had violated its Charter obligations. A decision on the motion is pending.

Cycle Ontario et al v Attorney General of Ontario

The positive and negative rights dichotomy was engaged once again in Cycle Ontario et al v Attorney General of Ontario.[viii] In that case, the applicants challenged an amendment to the Highway Traffic Act that would remove certain bike lanes in downtown Toronto as an infringement of their section 7 rights under the Charter. The Ontario government argued that the applicants were seeking a constitutional right to bike lanes on public roads.[ix] This characterization was rejected by the application judge, who found that the case was about the validity of the law passed by the government.[x]

The application judge found that there was compelling and essentially uncontradicted evidence from the applicants’ experts that the removal of the bike lanes would lead to more collisions and injuries involving cyclists.[xi] Accordingly, the application judge had no difficulty finding that the impugned provision under the Highway Traffic Act violated section 7 of the Charter and was not saved by section 1.[xii]

The government’s appeal to the Court of Appeal for Ontario was heard earlier this year, and a decision is pending.

UNDRIP and the Duty to Consult and Accommodate

Decisions from the Federal Court and British Columbia Court of Appeal provide guidance on the role of UNDRIP in interpreting section 35 of the Constitution Act, 1982 and the duty to consult and accommodate.

Kebaowek First Nation v Canadian Nuclear Laboratories

Kebaowek First Nation sought judicial review of the Canadian Nuclear Safety Commission’s decision to authorize construction of a nuclear waste disposal facility. The Federal Court granted Kebaowek’s application in part, finding that the Commission had failed to consider UNDRIP and the free, prior and informed consent (FPIC) standard in determining whether the duty to consult was met.^[xiii]

The Court clarified that the federal United Nations Declaration on the Rights of Indigenous Peoples Act^[xiv] gives rise to enhanced obligations under the Crown’s duty to consult and accommodate. UNDRIP is an “added contextual layer” that must be considered when assessing if the Crown fulfilled its duty to consult.^[xv]

The Court also clarified that FPIC is “not a veto,” but rather a “right to a robust process.”^[xvi] FPIC requires consultation that is informed by Indigenous perspectives, laws, knowledge, and practices and employs processes that are directed toward finding mutual agreement.^[xvii]

In this case, the nuclear waste disposal facility fell within the scope of Article 29(2) of UNDRIP, which requires that no disposal of hazardous materials take place on Indigenous lands without FPIC. Accordingly, the Commission was required to consider UNDRIP and FPIC in assessing whether the duty to consult was met. As that had not been done, the Court ordered the Commission to resume consultation with Kebaowek in accordance with UNDRIP.

Canadian Nuclear Laboratories’ appeal to the Federal Court of Appeal was heard in October 2025, and a decision is pending.

Gitxaala v British Columbia (Chief Gold Commissioner)

This case involved a challenge to British Columbia’s Mineral Tenure Act,[xviii] which allowed for the staking of mineral claims online without prior consultation with affected Indigenous communities.

The majority of the BC Court of Appeal held that DRIPA incorporates UNDRIP into the positive law of BC with “immediate legal effect,”^[xix] and that UNDRIP “engages the common law interpretive presumption of conformity…to apply and implement UNDRIP in domestic law.”^[xx] Assessing whether a law complies with UNDRIP may require assessing the extent to which the relevant article(s) of UNDRIP expresses a binding right, general principle, minimum standard, or aspiration.

In this case, the majority of the Court did not need to engage in a detailed analysis as the relevant UNDRIP article required FPIC.^[xxi] Since the Mineral Tenure Act provided for no consultation at all, it was clearly inconsistent with the relevant UNDRIP article.^[xxii]

The Province of BC has sought leave to appeal the decision to the Supreme Court of Canada.

As these cases make their way through the courts, their outcomes may further refine the scope of governmental obligations in the context of environmental harms and the protection of section 35 rights.

Get more caselaw updates from Ramani and Lauren by accessing the Ontario Legal Conference: Municipal, Planning and Environmental Lawprogram on demand.

About the Authors

Ramani Nadarajah joined the Canadian Environmental Law Association (CELA) as legal counsel in 1994. She is certified by the Law Society of Ontario as a Specialist in Environmental Law. She received her LL.B. (1989) and her LL.M. (2007) in administrative law from Osgoode Hall Law School.

As an associate at Aird & Berlis, Lauren Wortsman helps clients navigate complex legal issues at the intersection of environmental, Aboriginal and natural resources law. She works with Indigenous communities, governments and organizations to find innovative solutions that protect their rights and advance their self-determination, environmental and economic development goals. She also works with private and public sector clients, providing environmental advice in relation to environmental assessments and other regulatory processes related to air, water, fishe