In Mathur v Ontario Court Rejects Charter Challenge to Ontario’s Emissions Target  

by Daniel Kiesman

In Mathur v Ontario[1] the Ontario Superior Court of Justice rejected the constitutional challenge to the greenhouse gas emissions target set by Government of Ontario under s. 3(1) of the Cap and Trade Cancellation Act (“CTCA”).[2]


In 2018, the Government of Ontario through s. 3(1) of the CTCA set an emissions reduction target at 30% below 2005 levels by 2030. However, scientific research showed that to prevent serious adverse consequences in relation to health, food security, and human security, greenhouse gas emissions would need to be reduced by 52% below 2005 levels by 2030.  The Applicants, a group of young Ontarians, argued the target set by Ontario was too low, failing to adequately address climate change and leading to adverse future consequences for young people and for future generations.

The Applicants advanced two Charter arguments. First, by failing set the target high enough Ontario was authorizing and creating a level of emissions that will lead to serious adverse consequences and put the lives of Ontarians at risk, violating s. 7 of the Charter. Second, the Applicants argued the CTCA violates s. 15 of the Charter because it distinctly encumbers young people and future generations who will endure most of the impacts of climate change. In so doing, the Applicants argued the CTCA perpetuated a disadvantage since young people and future generations lack political decision making power and their interests are often ignored.


The judge found the challenges regarding the emissions target set by Ontario to be justiciable.[3] This is notable because the Federal Court found a past challenge to government climate action to be non-justiciable. In La Rose v Canada, the Federal Court held that a constitutional challenge of the Federal Government’s greenhouse gas emissions target was non-justiciable because the challenge was not focused on specific government action or legislation but rather focused on the Federal Government’s overarching policy positions regarding climate change.[4] The La Rose case was similarly brought by a group of young people concerned about the impacts of climate change and the decision in that case is currently under appeal to the Federal Court of Appeal. Nevertheless, the ruling in Mathur signifies that Charter challenges to government climate action can be justiciable when they are focused on a specific government action, which in this case was the target set under s. 3(1) of the CTCA.

Section 7

Under the s. 7 analysis the judge characterised the Applicants’ complaint as being that the emission target set by Ontario was not high enough. Therefore, the judged interpreted the Applicants’ s. 7 claim as a positive right claim, suggesting the Applicants were seeking a declaration that Ontario has a positive obligation to prevent the impacts of climate change from posing a threat to young people’s security of the person.[5] While noting in Gosselin v Quebec (Attorney General) the Supreme Court rejected the idea s. 7 creates a general positive obligation on governments to ensure citizens have the benefits of life, liberty and security of the person, the judge highlighted that Gosselin left open the possibility of positive obligations under s. 7 in certain unique circumstances.[6] The judge found that, “the Applicants make a compelling case that climate change and the existential threat that it poses to human life and security of the person present special circumstances that could justify the imposition of positive obligations under s. 7 of the Charter.”[7] The Court appeared open to the idea that the impacts of climate change could be special enough to for a court to impose a positive obligation but noted that if such a positive obligation were to be found there would likely be a different s. 7 analytical framework used in such cases. Ultimately, the judge assumed without deciding that a positive obligation under s. 7 arose in this case but went on to reject the s. 7 claim on the grounds that Ontario, in setting the emissions target, did not violate any principles of fundamental justice.[8]

While the result of the s. 7 analysis in this case may be disappointing to those concerned about the effects of climate change and government inaction, the Court’s analysis in Mathur presents a potentially important pathway forward for climate change focused constitutional litigation. The decision shows that courts may be open to imposing positive obligations on governments under s. 7. The decision is also notable for recognizing the unique and pressing challenges climate change posses to Canadian society such that climate change can be considered a special circumstance as articulated in Gosselin which may give rise to a positive obligation under s. 7. Furthermore, this decision adds to a growing chorus of courts across Canada which have expressed openness to the possibility that there may be a positive obligation on governments to adequately combat climate change. In La Rose the Federal Court did not foreclose the possibility that such positive obligations could exist.[9] In Kreishan v Canada (Citizenship and Immigration) the Federal Court of Appeal cautioned that s. 7 should not remain simply “frozen in time”[10] and expressly listed climate rights as a domain in which positive obligations under s. 7 could arise.[11] These decisions show that future litigation may be able to persuade a court that there are positive obligations on governments, under s. 7, to adequately combat climate change.

Section 15

With respect to the Applicants’ s. 15 claim, the Court applied the s. 15 test following the guidance given recently by the Supreme Court in R v Sharma.[12] At the first step of the test the judge accepted that young people are disproportionately affected by climate change.[13] However, the judged stressed that any disproportionate impact is caused by climate change itself and not by emissions targets set by Ontario through s. 3(1) of the CTCA.[14] As such, the Applicants’ claim failed to show Ontario’s actions created or contributed to the disproportionate affects of climate change faced by young people. While the emissions target is not high enough to thwart the impacts of climate change, the emissions target itself does not cause or contribute to the adverse effects of climate change that young people will face. Given the requirements set out in Sharma for claimants to show causation at the first stage of the s. 15 analysis, the judge concluded the s. 15 must fail because the requisite causation could not be established in this case.[15]

The judge, echoing the Supreme Court in Sharma, also noted there is no positive obligation of governments to address inequalities through remedial legislation.[16] The emission target is part of a remedial scheme aimed at addressing climate change. The Supreme Court stated that when a government chooses to address inequality it can legislate incrementally and leave gaps between members of protected groups who may be affected by such legislation and members of non-protected groups unaffected by such legislation.[17] The emissions target in question were viewed by the Court as incremental and remedial legislation Ontario chose to enact to address the issue of climate change. Therefore, any gap the CTCA creates does not in itself infringe s. 15.[18]

The Applicants also advanced a s. 15 argument claiming that since the impacts of climate change will only get worse over time, young people and future generations will face the brunt of impacts of climate change since they will live longer into the future. The judge also rejected this argument. The Court again noted that a claim relating to the effects of climate change on future generations fails to meet the causal burden at the first step of the s. 15. The more impactful future effects of climate change are not caused by Ontario’s emissions target but caused by climate change.[19] Furthermore, the judge appeared skeptical that the Applicants could even advance a s. 15 claim on behalf of future generations. Since everyone who lives into the future will be affected by climate change, this is not a distinction based on age because people of all ages will face the impacts of climate change in the future. Therefore, the judge held the Applicant’s claim is based solely on a temporal distinction and cannot succeed because such a distinction is not an enumerated or analogous ground.[20] Even if future generations could be considered to fall under the enumerated ground of age, or recognized as an analogous ground itself, the judge held that the claim would still fail. Citing Sharma, the judge noted that the disproportionate effects felt by future generations, would be a “gap” which already existed and was left unaffected by emissions target set by Ontario and therefore would not infringe s. 15.[21]

Mathur illustrates the impact of the decision in Sharma on s. 15 claims. The evidentiary burden on claimants to show a government action “creates or contributes to a disproportionate impact,”[22] at the first stage s. 15 test and the Supreme Court’s assertion that it does not infringe s. 15 to leave gaps between different groups so long as government action did not cause those gaps are important developments which drive the judge’s s. 15 analysis in this case.[23] This guidance in Sharma may prove to be difficult hurdles to climb for litigants bringing s. 15 challenges to government climate actions. Governments do not create or cause climate change. While governmental inaction will not abate the adverse consequences of climate change, it may prove difficult to show inadequate government action independently cause the impacts of climate change to worsen. Furthermore, as the judge accepted, young people already bear the brunt of the impacts of climate change. However, the gap between young people and other groups in society in relation to the adverse effects of climate change is again created by climate change. Government actions which will fail to remedy the issue of climate change will simply leave these gaps unaffected and therefore, per Sharma would not infringing s. 15.

Looking Forward

Mathur was the first case to substantively tackle a constitutional challenge to a government climate change policy and there are important takeaways to consider moving forward. First, constitutional challenges to government climate actions need to be aimed at specific government actions or legislation in order to be justiciable. Simply pointing to a broad constellation of government policies or positions on climate change will likely be viewed by courts as non-justiciable. Second, courts appear to be open to entertain arguments that climate is a special domain in which positive obligations on governments could potentially arise under s. 7. Given the right case with the right facts this could prove to be an exciting area for significant development of the law and advance climate activists’ cause. Third, the decision in Mathur illustrates that, given the majority decision in Sharma, s. 15 challenges to government climate actions will likely prove difficult to successfully make out. Overall, while the result in Mathur may be discouraging for individuals concerned about climate change, the decision shows there remain potentially viable avenues for future successful constitutional challenges to government climate actions.

Daniel Kiesman is a 1L JD candidate at the Faculty of Law and is an Asper Centre Summer Research Assistant

[1] Mathur v Ontario, 2023 ONSC 2316 [Mathur].

[2] Cap and Trade Cancellation Act, 2018, SO 2018, c 13, s 3(1).

[3] Mathur, supra note 1 at para 106.

[4] La Rose v Canada, 2020 FC 1008 at paras 40—41 [La Rose].

[5] Mathur, supra note 1 at paras 122, 124, 132.

[6] Ibid at paras 125, 137 citing Gosselin v Quebec (Attorney General), 2002 SCC 84 at paras 81—83.

[7] Ibid at para 138.

[8] Ibid at paras 142.

[9] La Rose, supra note 4 at paras 69—72.

[10] Kreishan v Canada (Citizenship and Immigration), 2019 FCA 223 at para 139.

[11] Ibid.

[12] R v Sharma, 2022 SCC 39 [Sharma].

[13] Mathur, supra note 1 at para 178.

[14] Mathur, supra note 1 at para 178.

[15] Ibid citing Sharma, supra note 12 at para 42.

[16] Mathur, supra note 1 at para 178 citing Sharma, supra note 12 at paras 40, 63.

[17] Sharma, supra note 12 at paras 40, 63—64.

[18] Mathur, supra note 1 at para 178.

[19] Ibid at para 179.

[20] Ibid at para 180.

[21] Ibid at para 182.

[22] Sharma, supra note 12 at para 42.

[23] Ibid at paras 40, 42; Mathur, supra note 1 at para 178.