Climate change is happening now. The U.S. and the world are warming, global sea level is rising, and some types of extreme weather events are becoming more frequent and more severe. These changes have already resulted in a wide range of impacts across every region of the country and many sectors of the economy. Today, America needs reliable scientific information about current and future changes, impacts, and effective response options. The U.S. Global Change Research Program—which released the Third National Climate Assessment in May 2014—is at the center of fulfilling this critical need. Scroll down to learn more.