MONTREAL, Oct 28 — Young Canadians testified yesterday to a “sense of despair” during a landmark climate trial over the federal government’s alleged climate policy failures and the “scary” consequences of global warming.

The latest testimony from the 15 plaintiffs who brought the suit, all aged 17 to 25, is part of a growing global movement among environmental activists seeking to use courts to force government accountability on climate change.

“I want the court to know that we are doing this for our future,” Sadie Vipond said on the stand.

The 20-year-old student hails from Calgary, in western Canada, where she described thick smoke and overwhelming heat that descends year after year on her hometown.