A group of 21 youths who accuse the U.S. government of failing for decades to properly address climate change defeated the Trump administration’s attempt to keep the dispute out of court.

The U.S. Court of Appeals in San Francisco ruled Wednesday that a novel and sweeping case, which the Obama administration first tried to extinguish in 2016, can proceed toward a trial. Trump’s Justice Department is expected to ask the Supreme Court to shut it down.

The group of mostly teenagers in Oregon alleged in a 2015 complaint that government policies have exacerbated global warming in violation of their rights — and those of future generations — under the U.S. Constitution.