For more than 50 years, the US government has been aware that the burning of fossil fuels is increasing the concentration of carbon dioxide in Earth’s atmosphere and thereby raising the planet’s temperature. Despite this knowledge, the federal government has never adopted a comprehensive plan to remedy the problem, and even today the White House and Congress continue to pursue energy policies that permit and promote the continued consumption of fossil fuels – and that will not achieve meaningful climate recovery in the coming decades. Even if the United States and other nations keep all of the promises they made in the recent Paris climate deal, the resulting reductions in greenhouse gas emissions will not be enough to stabilize the climate. The author, an attorney who represents 21 youth plaintiffs and a well-known climate scientist, describes a lawsuit that her clients are bringing in an effort to force the US government to end its systemic discrimination against young people and future generations and adopt policies that protect them from dangerous climate change. It is their hope that the third branch of the federal government, the judiciary, will step in to protect their fundamental rights.