COURT OF APPEAL FOR ONTARIO
Coroza, Sossin and Gomery JJ.A.
BETWEEN
Sophia Mathur, a minor by her litigation guardian Catherine Orlando, Zoe Keary-Matzner, a minor by her litigation guardian Anne Keary, Shaelyn Hoffman-Menard, Shelby Gagnon, Alexandra Neufeldt, Madison Dyck and Lindsay Gray
Applicants (Appellants/Moving Parties)
and
His Majesty the King in Right of Ontario
Respondent (Respondent/Responding Party)
and
Assembly of First Nations, Canadian Association of Physicians for the Environment, David Asper Centre for Constitutional Rights, For Our Kids, Friends of the Earth Canada and Indigenous Climate Action
Interveners
Nader R. Hasan, Justin Safayeni, Spencer Bass, Fraser Andrew Thomson, Julia Croome and Reid Gomme, for the moving parties
S. Zachary Green, Padraic Ryan and Sean Kissick, for the responding party
Heard: in writing
REASONS FOR DECISION
1In Mathur v. Ontario, 2024 ONCA 762, 173 O.R. (3d) 81, this court allowed an appeal by the moving parties, whose Charter application had been dismissed by the application judge. The panel remitted the matter to the application judge to decide whether the responding party, Ontario, had breached ss. 7 and 15 of the Canadian Charter of Rights and Freedoms. Due to an administrative slip, the court did not issue and enter its final order allowing the appeal.
2After this court made its decision, Ontario applied for leave to the Supreme Court of Canada. The moving parties opposed the application and brought their own application for conditional leave to cross-appeal. The Supreme Court denied both applications: [2024] S.C.C.A. No. 534.
3Shortly before the matter was reheard by the application judge, Ontario passed legislative amendments that repealed provisions pertinent to the appeal.
4The moving parties now bring this application to reopen the hearing of the appeal. In seeking to reopen the appeal, the moving parties ask the court to consider additional grounds of appeal raised before the panel, but which did not form the basis of the court’s decision. They rely on the court’s inherent power to reopen an appeal provided the formal order disposing of the appeal has not yet been taken out and entered.
5For the reasons that follow, we dismiss this application.
I. Factual Background
6The lengthy history of this litigation is set out in the court’s original decision. However, to provide some context for this decision not to reopen the appeal, a summary of that litigation is needed.
7In 2018, Ontario enacted the Cap and Trade Cancellation Act, 2018, S.O. 2018, c. 13 (the “CTCA”). Section 16 of the CTCA repealed the Climate Change Mitigation and Low-carbon Economy Act, 2016, S.O. 2016, c. 7 (the “Climate Change Act”), which contained greenhouse gas emission reduction targets. Section 3(1) required the government to set new reduction targets.
8The target implemented by Ontario called for a much smaller reduction than that prescribed under the Climate Change Act and, according to the unchallenged evidence at the application hearing, fell short of the reduction recommended by international scientific consensus.
9The moving parties are Ontario youth. They brought an application challenging the target and enacting provisions of ss. 3 and 16 of the CTCA, as well as the targets set by Ontario pursuant to them, on the basis that they violated the appellants’ rights under ss. 7 and 15 of the Charter. They sought an order declaring that their Charter rights had been violated and requiring Ontario to set a science-based emissions reduction target and revise its climate change plan in accordance with international standards.
10The application judge dismissed the application. The application judge characterized the moving parties’ claim as a positive rights claim. She held that: (i) any deprivation of the right to life or security of the person which flowed from Ontario’s emissions targets was not contrary to the principles of fundamental justice under s. 7; and (ii) s. 15 did not impose a positive obligation on Ontario to take specific steps to combat climate change. As a result, she concluded that the moving parties’ Charter rights were not breached.
11On appeal, this court concluded that the application judge erred in approaching this matter as a positive rights case. By enacting the CTCA, Ontario voluntarily assumed a positive statutory obligation to combat climate change and to produce a plan and target for that purpose. Ontario was therefore bound to produce a plan and a target that were Charter-compliant.
12Because the application judge did not assess the question of Charter compliance through the correct analytical lens, she did not address whether Ontario failed to produce a plan and a target that was Charter-compliant in accordance with its statutory mandate.
13Accordingly, this court remitted the matter back to the application judge to conduct a proper determination of the ss. 7 and 15 issues raised by the moving parties. In its disposition, this court set out the reasons for the remit at paras. 76-79:
As noted above, we decline to decide the application and instead remit the matter for a new hearing. In doing so, we acknowledge the court of first instance’s institutional advantage in making the findings necessary to fairly determine whether the appellants’ rights were breached or whether they are entitled to the relief that they seek: see Canadian Council for Refugees, at para. 176. For instance, the application judge indicated that there was insufficient evidence to allow her to address the adverse effects distinction concerning young people’s liberty and future life choices that are being constrained by decisions being made today over which they have no control.
The application judge further held that it was unnecessary for her to determine whether societal preservation or ecological sustainability are unwritten constitutional principles because they would not affect her analysis under ss. 7 and 15 of the Charter. Given our disposition of the appeal, it is also unnecessary for us to decide this issue. However, how this issue may inform the question of whether the Target and Plan are Charter compliant because of the statutory obligation to combat climate change that Ontario has imposed on itself is another question that may require reconsideration at the new hearing.
Further, as earlier indicated, the interveners have raised issues that were not determined by the application judge. We agree with the application judge that if the appellants wish to pursue these issues, they should be properly pleaded. As a result, the appellants may wish to consider whether they should seek to amend their pleadings.
We therefore remit the application for a new hearing before the application judge, as her sitting schedule permits. If she is unavailable to hear the application, then it shall be heard by another judge of the Superior Court, as assigned.
14The court’s disposition also clarified the broad scope of issues to be remitted before the application judge, at para. 80:
It will be open to the parties to determine whether, given the issues as now framed or upon any amendment to the pleadings, including the above noted issues raised by the interveners, and any further issues the parties wish to pursue, including the application of s. 1 of the Charter, the evidentiary record will require amplification; whether the application should be converted into an action; or whether there should be a trial of an issue or issues. We recommend the parties seek case management to define the next steps and a timetable for their execution in these proceedings. (Emphasis added.)
15As noted above, in what appears to be an administrative oversight, this court never formally issued and entered its final order.
16On November 6, 2025, several months after the Supreme Court denied leave and less than a month before the scheduled rehearing before the application judge, the Ontario government introduced Bill 68, An Act to implement Budget measures and to enact and amend various statutes, in the Legislative Assembly of Ontario. Schedule 1 of Bill 68 repealed ss. 3-5 of the CTCA. Bill 68 received royal assent on November 27, 2025. Ontario has taken the position that, following passage of the legislation, this application has become moot.
17In response, the moving parties have brought this motion to reopen the appeal. Pending our decision on the motion, the application judge adjourned the rehearing of the application sine die.
18The crux of the moving parties’ submission is that, in light of the repeal of the legislation, this court should consider the additional grounds of the appeal raised before the court in written and oral argument but not subject to adjudication in the decision.
II. Analysis
19The court may reopen an appeal on one of two bases: (i) the court’s inherent jurisdiction to reopen the appeal because no order was taken out to dispose of it; or (ii) the court’s power to set aside or vary its order pursuant to r. 59.06 of the Rules of Civil Procedure, R.R.O. 1990, Reg. 194.
20In their reply factum, the moving parties concede r. 59.06 “does not technically apply in these circumstances” because no order was taken out but submit the test to be applied remains “largely the same”. In the moving parties’ submission, “[u]ltimately, the question is whether it is in the interests of justice to reopen the appeal.”
a. The court’s inherent power to reopen the appeal
21Rule 61.16(6.1) of the Rules of Civil Procedure governs motions to set aside or vary decisions of a panel: “Subject to rules 37.14 and 59.06, an order or decision of a panel of an appellate court may not be set aside or varied under these rules.”
22In addition to r. 61.16(6.1), the court also has inherent power to reopen an appeal before a formal order is taken out and entered, when it is in the interests of justice to do so: e.g., First Elgin Mills Development Inc. v. Romandale Farms Ltd., 2015 ONCA 54, 381 D.L.R. (4th) 114, at para. 7; Meridian Credit Union Limited v. Baig, 2016 ONCA 942, 6 C.P.C. (8th) 33, at para. 7. This is because, generally speaking, there is no jurisdictional impediment to the court reconsidering its decision when the formal order disposing of the appeal has not yet been taken out and entered: Mujagic v. Kamps, 2015 ONCA 360, 125 O.R. (3d) 715, at para. 7, leave to appeal refused, [2015] S.C.C.A. No. 330; McGrath v. Joy, 2023 ONCA 46, 166 O.R. (3d) 302, at para. 14. Until the formal order is taken out, the court is not functus officio: McGrath,at para. 14.
23That said, a party seeking to reopen an appeal after the appeal decision has been issued faces a high hurdle: Chuang v. Toyota Canada Inc., 2016 ONCA 852, 66 C.L.R. (4th) 177, at para. 7. Reopening an appeal is a “rare event” that “will occur only where ‘a very serious injustice’ will result absent reconsideration of the matter”: Geliedan v. Rawdah, 2020 ONCA 339, 446 D.L.R. (4th) 440, at para. 8, citing Doman Forest Products Ltd. v. GMAC Commercial Credit Corp. - Canada, 2005 BCCA 111, 209 B.C.A.C. 197, at para. 6; and First Elgin Mills Development Inc., at para. 8; Mujagic, at para. 12; see also McGrath, at para. 15.
24The moving parties submit that this is one of those rare cases where the interests of justice require us to rehear the appeal on its merits to preserve the rule of law. They argue that Ontario passed legislation to evade constitutional scrutiny and defeat the rehearing ordered by the court before it begins. The moving parties assert that Ontario has prevented them from seeking a remedy by making these legislative changes after the Supreme Court dismissed the applications for leave.
25Accordingly, in the moving parties’ submission, Ontario’s conduct has made it necessary for the court to determine the unresolved aspects of the appeal.
26Ontario argues that there is no basis for the motion to reopen the appeal, as the moving parties can advance their claims before the application judge at the rehearing. It further notes that any final order made by the application judge after the rehearing would be subject to an appeal as of right to this court. Should either party choose to appeal from the resulting order, this court would have the benefit of the application judge’s reasons for decision on these complex issues.
27The power to reopen an appeal should be exercised sparingly and only where it is clearly in the interests of justice. In our view, the interests of justice do not warrant reopening this appeal. We reach this conclusion for two reasons.
28First, the motion to reopen is anchored in the view that the repeal of the legislation that formed the basis of the appeal decision makes the remittal to the application judge moot. In our view, it is premature to conclude that the issues remitted to the application judge will no longer be decided. The application judge retains discretion to hear the matter notwithstanding the repeal of the legislation. This determination would be subject to the test set out in Borowski v. Canada (Attorney General), 1989 CanLII 123 (SCC), [1989] 1 S.C.R. 342. It would be inappropriate for this court to assume the result of that analysis.
29Second, this court’s decision remitting the matter back to the application judge made clear that the record and findings on appeal and at the initial application were insufficient to allow a determination on the Charter claims raised by the moving parties. That determination applies equally to the broader Charter claims advanced but not dealt with by the panel in its reasons.
30The highlighted portion of this court’s remedy remitting the matter to the application judge makes it clear that it is open to the moving parties to clarify, reframe or expand upon the issues to be determined by the application judge in relation to their Charter claims, including through amendments to the pleadings. This court observed that the record may require amplification to enable such findings to be made.
31Moreover, this court also acknowledged the moving parties may seek to amend their pleadings to incorporate arguments raised by interveners for the first time on appeal. These additional pleadings will require the parties to further augment the record.
32In sum, we reiterate the statement made by the court in its decision, at para. 76, as reproduced above: “[W]e acknowledge the court of first instance’s institutional advantage in making the findings necessary to fairly determine whether the appellants’ rights were breached or whether they are entitled to the relief that they seek”.
33In these circumstances, the proper next step in this litigation is for the parties to follow the remedy and guidance set out by this court in remitting the matter for further adjudication by the application judge.
b. The court’s authority to set aside or vary an order under r. 59.06
34In light of our conclusion that it is not in the interests of justice to reopen, it is not necessary to canvass the scope of this court’s jurisdiction to vary an order not formally entered and issued pursuant to r. 59.06. The moving parties concede that r. 59.06“does not technically apply in these circumstances”.
III. Disposition
35For these reasons, the motion to reopen the appeal is dismissed.
36As the successful party, Ontario seeks costs for this motion. The moving parties have requested an opportunity to make brief submissions explaining why they should not be subject to a costs award. Accordingly, this court will receive written submissions no more than 5 pages in length, to be filed within 14 days of the release of this decision.
“S. Coroza J.A.”
“L. Sossin J.A.”
“S. Gomery J.A.”