The Supreme Court of the Netherlands on Friday ordered the government to cut the nation’s greenhouse gas emissions by 25 percent from 1990 levels by the end of 2020. It was the first time a nation has been required by its courts to take action against climate change.

Because of climate change, “the lives, well being and living circumstances of many people around the world, including in the Netherlands, are being threatened,” Kees Streefkerk, the chief justice, said in the decision. “Those consequences are happening already.”

Michael Gerrard, director of the Sabin Center for Climate Change Law at Columbia University, said the decision was groundbreaking. “There have been 1,442 climate lawsuits around the world,” he said. “This is the strongest decision ever. The Dutch Supreme Court upheld the first court order anywhere directing a country to slash its greenhouse gas emissions.”

It was the third court victory in the case for the environmental group Urgenda, which filed the lawsuit in 2013 against the Dutch government with nearly 900 co-plaintiffs.