The International Court of Justice, which is the preeminent source of international law, issued a groundbreaking advisory opinion on climate change this month.

The opinion concludes that states failing to take action against the production and consumption of fossil fuels, such as by issuing new exploration permits or by continuing to provide subsidies to the fossil fuel sector, are committing “internationally wrongful acts.” The consequences for rich, fossil-fuel producing countries, such as Canada, include an obligation to compensate poorer countries facing the brunt of climate impacts.

While the ICJ’s opinion is not, in itself, legally binding, the landmark opinion will empower the hundreds of legal challenges being brought against governments and corporations around the world for failing to address the climate crisis. More than 200 such cases were filed last year, and the ICJ opinion will provide the legal basis for many more.

As the Grantham Research Institute’s latest climate change litigation snapshot makes clear, these cases are not political theatre. Climate litigation succeeds more often than not, and it is having a very real impact on policy making and corporate decision making around the world. As the right to a safe climate is increasingly entrenched in law, it becomes harder and harder for governments and corporations to wilfully ignore climate science.

Canadian courts have been more reluctant than others to rule on such cases.