The Obama administration is more certain than ever that global warming is changing Americans’ daily lives and will worsen—conclusions that scientists will detail in a massive federal report to be released Tuesday. Once people thought global warming was more in the future and more of an issue in other parts of the world, but the National Climate Assessment will emphasize how the United States is already paying the multibillion-dollar price for man-made climate change, said study co-author Donald Wuebbles, a climate scientist at the University of Illinois. “We’re already seeing extreme weather and it’s happening now,” Wuebbles said Monday. “We’re...