Climate change is the greatest challenge facing the United States—and the world—over the next decade and beyond. The impacts of climate change have already been deadly: More than 3,000 Americans have died in weather- and climate-related disasters in the past two years.1 Public health experts warn that climate change threatens the quality of America’s air and water.2 Natural disasters have cost the United States more than $450 billion in the past three years and are projected to cost $54 trillion globally by 2040.3 By the end of the century, crop damage, lost labor, and extreme weather threaten to shrink the U.S. economy by as much as 10 percent, or $500 billion—almost double the cost of the 2009 Great Recession.4 The U.S. military warns that climate change will multiply the national security threats facing the country. Climate change is a crisis that touches every element of our society. It exacerbates systemic economic and racial inequality and simultaneously threatens public health; national security; the safety and well-being of communities; and the strength of the economy. A year ago, in October 2018, the issue took on new urgency when the Intergovernmental Panel on Climate ...