With conflict erupting over a natural gas pipeline in northwestern British Columbia, two Wet'suwet'en hereditary chiefs are suing Ottawa in a bid to force the federal government to take action on climate change.

If the claim filed in federal court this week by leaders of the Likhts'amisyu Clan succeeds, Ottawa would be forced to revisit the approval of projects like the $6-billion, 670-kilometre Coastal GasLink pipeline, if they kept Canada from meeting international commitments to lower greenhouse gas levels

"What the Likhts'amisyu are saying to the federal government is that you've talked the talk, now it's time to walk the walk," said Richard Overstall, the lawyer for the chiefs.

"And allowing these high greenhouse gas emitting projects to continue for 40 years isn't walking the walk."

'A threat to their identity'

Although the hereditary chiefs who filed the suit — Dini Ze' Lho'Imggin, also known as Alphonse Gagnon and Dini Ze' Smogilhgim — are also opposed to the Coastal GasLink pipeline, Overstall claimed the timing of the federal court claim is a "coincidence" in terms of protests which have erupted across the country.

The two chiefs represent a pair of houses that comprise one of five Wet'suwet'en clans. According to the lawsuit, each is responsible for the welfare and territory of house members.

Wet'suwet'en hereditary chiefs take part in a rally in Smithers B.C. Two chiefs have now launched a federal court claim in a bid to force the Crown to act on climate change. (Jason Franson/The Canadian Press)

The lawsuit describes global warming as an "existential threat" that has specific impact on the rights of the Wet'suwet'en as guaranteed under Section 7 of Canada's Charter of Rights and Freedoms: the right to life, liberty and security of the person.

"It is a threat to their identity, to their culture, to their relationship with the land and the life on it, and to their food security," the statement of claim reads.

"It is a responsibility because large fossil-fuel infrastructure projects are proposed to cross their territories."

'Unwillingness' to act

The court claim says the federal government has assured Canadians since at least 1988 that "it would establish laws and policies to meet its international climate commitments."

Those promises culminated in a promise under the Paris climate agreement in 2015 to keep global warming well below 2 C above pre-industrial levels.

Map of the planned Coastal link LNG Pipeline, where it will interesect with Wet'suwet'en territory. (CBC News)

But the chiefs claim the Crown has "repeatedly failed and continues to fail to fulfil its constitutional duty" to protect their charter rights "due to its unwillingness to establish and to implement the laws, policies and actions needed" to ensure that Canada lives up to its word.

"Already, the plaintiffs have experienced significant warming effects on their territories," the lawsuit reads.

"These effects include pine bark beetle infestations, forest fires, and salmon population declines, in part attributable to climate change."

The chiefs claim Ottawa has deliberately "fettered its law-making power" — tied its own hands — "by failing to pass environmental assessment legislation that would allow the executive branch to cancel or significantly amend its approval of a high greenhouse gas emitting project in the event that Canada can demonstrably not meet its international global warming commitments or its obligations to the citizens of Canada."

Groundbreaking claim?

The chiefs want a declaration from the court that the Crown has a constitutional duty to act to keep global warming between 1.5 C and 2 C above pre-industrial levels.

They also want a declaration that Canada has an obligation to meet those targets under a section of the Constitution that requires government to maintain "peace, order and good government."

And they're seeking a requirement for Ottawa to prepare "a complete, independent and timely annual account of Canada's cumulative greenhouse gas emissions" with the ability to cancel approval for projects that threaten climate goals.

While the suit has the possibility to be precedent setting if it succeeds, Overstall points out the courts have told Parliament to strike down parts of statutes in the past as well as "reading in" certain clauses to existing legislation in order to meet constitutional requirements.

He also pointed to a lawsuit announced last year by a group of 15 youths across Canada as another example of the intersection between the charter right to security of the person and the threat of climate change.

"I think all of these would be groundbreaking, because global warming and its effect on Indigenous people and young people and everybody, is groundbreaking in itself," Overstall said.

The Crown has yet to file a response to the claim.