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A group of youth stand together with serious expressions. They are sitting on grass and rocks brought into a studio.

Photographer Tilly Nelson, set design Kendra Martyn & Kira Evenson

Ontario
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#GenClimateAction: Mathur et. al. v. His Majesty in Right of Ontario

Mathur et. al. v. His Majesty in Right of Ontario

November 29, 2019

Every few decades, a court case comes along that captures a defining issue of its time. Mathur is one of those cases.  

In 2019, seven youth in Ontario made Canadian legal history when they took their provincial government to court for slashing its climate targets. But to the youth behind the case — and to their many supporters — it represents something far greater than just Ontario’s climate targets. 

After a landmark decision from the Ontario Court of Appeal in 2024, the Mathur case is heading back to the Ontario Superior Court of Justice, where it could define whether governments have constitutional obligations to take on one of the most pressing human rights issues of the 21st century: the climate crisis. 

What’s the problem? 

Climate change threatens everything we care most about — our way of life and well-being, our health and security, our environment and biodiversity, our homes, our economy, and especially the next generation’s future.  

Courts around the world have already found that the climate crisis is the greatest intergenerational injustice ever committed.  

Yet in Canada, rather than addressing this existential threat, governments at all levels have failed to deliver on their climate commitments. There is no better example of this than the Ontario government’s rollback of its climate targets in 2018. Their actions have put our rights to life, security and equality at risk.  

We cannot continue to sacrifice the future of younger generations for short-term profits. 

Young people are leading the charge in the fight for climate justice — taking to the streets, the polls and, with the Mathur case challenging the Ontario government’s actions, to the courts.  

Make no mistake, these seven young Ontarians are not alone. Courts around the world are increasingly siding with citizens and forcing governments to tackle the climate crisis. It’s only a matter of time before this happens in Canada, too.  

What are we fighting for?  

The youth at the forefront of this case are fighting for government accountability, intergenerational justice, and above all, their rights to a safe climate and a livable future.  

When our governments (repeatedly) fail to protect us from the threats of climate change, it is not only the role of the courts to step in it’s their duty. 

This is a make-or-break moment for climate justice, and the Mathur case has the power to turn the tide in the fight against the climate crisis.

Mathur isn’t just a climate case — it’s a human rights case, too. 

At a time when the science says we must do more to combat the climate emergency, the Ontario government did the exact opposite. This is unacceptable, and, as the youth in the Mathur case have argued, unconstitutional — putting their fundamental Charter rights to life, security, and equality at risk. 

Their actions have put our rights to life, security and equality at risk. 

Our youth clients are part of what we affectionately call Generation Climate Action (#GenClimateAction) — remarkable young people around the world who have left their classrooms, put their plans on hold, and taken to the courts to speak truth to power about how the climate crisis impacts their future. 

Making legal history in the fight for climate justice 

  • In 2018, the Ontario government rolled back the province’s climate targets. Seven brave young Ontarians (the youngest who were just twelve years old at the time) decided to do something about it. 
  • In 2019, Alex, Beze, Madi, Shae, Shelby, Sophia, and Zoe launched a landmark case and took the Ontario government to court for further fuelling the worsening climate crisis and putting their generation’s future at risk. 
  • We successfully fought off government attempts to have the case thrown out of court, and in 2022 became the first climate Charter challenge to ever be heard on its merits and finding that Ontario’s contributions to the climate crisis are putting its citizens’ lives at risk. 
  • We made history again in October 2024, when a groundbreaking decision from the Ontario Court of Appeal concluded that climate change is a Charter issue that governments must answer for in court and confirmed that it is “indisputable” that climate change is threatening the lives and health of Ontarians. 
  • In May 2025, the Supreme Court of Canada rejected Ontario’s attempt to appeal our win on key legal issues. By refusing to take up Ontario’s appeal, this landmark decision from the Ontario Court of Appeal that climate targets must comply with the Charter is now the law of the land.  
  • Now, with the wind in our sails, we’re heading back to the Ontario Superior Court of Justice as quickly as we can, to seek an order forcing the government to set science-based climate targets. Before too long, we will know more details about our return court date (stay tuned!).   

This case already has made one thing clear: climate change threatens our fundamental human rights 

Courts around the world are at a crossroads: will they step in to hold governments accountable for wrecking the climate? Or will they leave it to future generations to clean up the mess? 

Now that the Ontario Court of Appeal has made it abundantly clear that the climate crisis risks our most fundamental rights, the Ontario Superior Court of Justice has the opportunity to step in and protect our future. 

How the court sets governments’ constitutional obligations to confront the climate crisis could have far-reaching impacts on our lives and our laws for decades to come. 

Our governments have continued to fuel the climate crisis. It’s time for the courts to step in.  

When governments violate our Charter protected rights on a massive scale, it’s not only the role of the courts to hold them accountable — it’s their duty. 

That’s why concerned citizens around the world are turning to the courtrooms in their fights for climate justice, and it’s working!  

Part of a global movement of citizen-led climate action  

Judges around the world are increasingly siding with citizens and forcing governments to tackle the climate crisis. We’ve seen it in Switzerland, the Netherlands, Colombia, South Korea and in a growing number of countries. By bringing science into the courtroom and representing clients with ringing claims to justice, we are seeking legal precedents that can guide Canada to a climate-safe future, too. 

As the Mathur case heads towards a showdown in court, we stand at the precipice of a historic, youth-driven win for climate rights under our constitution.  

We believe that win is coming, and when it does it will be a gamechanger for climate action in Canada.

Apr 2025
Photo credit: Tilly Nelson Photography.
blog

Racing the clock: A youth-led climate case that’s set to make history, again 

Every few decades, a court case comes along that confronts the most urgent challenge of its time.
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The case at a glance:

For media:

Other legal resources: