The U.S. Supreme Court has declined to hear a petition from 21 young climate activists who sought to revive a groundbreaking lawsuit against the federal government. The activists argued that the government's energy policies violate their constitutional rights by failing to protect them from the impacts of climate change. The court's decision effectively ends the case, which has been described as one that 'ignited a movement' in environmental law. This ruling follows previous attempts by the activists to compel the government to take more aggressive action against climate change, marking a significant moment in the ongoing legal battles surrounding environmental policy and youth advocacy.