In 2015, 21 American youth filed the internationally-renown case Juliana v. United States, claiming that affirmative acts of the federal government violate their constitutional rights and the rights of future generations. Juliana v. United States is science-based, seeking to halt state-created danger and other constitutional harms and to enforce legal rights to a climate system capable of sustaining life. The response of the Biden-Harris Administration and the Supreme Court to Juliana will signal to the world whether the US federal government is serious about grounding long-term solutions to the climate crisis in our Constitution.