“Climate change, Mr. Obama often says, is the greatest long-term threat facing the world, as well as a danger already manifesting itself as droughts, storms, heat waves and flooding. More than health care, more than righting a sinking economic ship, more than the historic first of an African-American president, he believes that his efforts to slow the warming of the planet will be the most consequential legacy of his presidency.”

“Mr. Obama immersed himself in the scientific literature, which left little doubt that the planet was warming at an accelerating rate. “My top science adviser, John Holdren, periodically will issue some chart or report or graph in the morning meetings,” he said, “and they’re terrifying.”

http://www.nytimes.com/2016/09/08/us/politics/obama-climate-change.html