Buried in the holiday weekend is a major scientific report that presents a harsh warning of the consequences of climate change for the United States. The report was issued by 13 federal agencies and predicts that if significant steps are not taken to rein in global warming, we’ll see as much as a 10% knock off the size of the American economy by the end of the century. The report puts a price tag on the cost to the U.S. economy of projected climate impacts: nearly $300 billion from heat-related deaths, rising sea levels and infrastructure damage. This comes at a time when President Trump has mocked climate change in tweets and taken aggressive steps to allow more pollution from vehicle tailpipes and power plant smokestacks, and has vowed to pull the United States out of the Paris Agreement. The U.S. needs a leader on this front, not someone who doesn’t understand the science behind it and doesn’t listen to those who do.