Canada will stand trial for climate inaction after an appeals court reopened the door for a group of 15 young environmental activists who sued the federal government four years ago on the issue.

The Federal Court of Appeal ruled that a trial must be held to determine whether the actions of Justin Trudeau's government violate the rights of the young plaintiffs under the Canadian Charter of Rights and Freedoms, according to a decision made public on Thursday.

"Climate change is having a dramatic, rapidly unfolding effect on all Canadians," said the ruling, seen by AFP.

"It is also beyond doubt that the burden of addressing the consequences will disproportionately affect Canadian youth."

In October 2019, 15 young people, aged 10 to 19, sued the federal government, which they claimed was contributing to global warming by failing to implement an ambitious plan to reduce greenhouse gas emissions.

A year later, a federal judge rejected their request, but the Court of Appeal overturned that decision on Wednesday.

"It's the least we can do to have the right to a trial to discuss what is an existential threat," Albert Lalonde, one of the plaintiffs and an environmental activist now aged 21, told AFP.

The law student said he considers it "hopeless to have had to wait four years" to reach this stage in the proceedings.

Others found reason for optimism.

"I see this going beyond the federal government. This should put every province blocking climate action on notice that there can be legal consequences for inaction," Tom Green, a climate advisor to the David Suzuki Foundation, an environmental organization that supports young people, said in a statement.

Elsewhere in the world, numerous lawsuits have been filed to force governments to act against the climate crisis, including Germany, the Netherlands and France.

Canada, which is warming faster than most countries due to its geographic position, has in recent years contended with extreme weather events of increasing intensity and frequency.