MOUNTAIN VIEW, Calif. — Humanity must act now if it hopes to stave off the worst impacts of climate change, NASA chief Charles Bolden says. On the 1950 map, only a small corner of the southwestern U.S. blushes dark red, indicating average July temperatures of at least 105 degrees Fahrenheit (41 degrees Celsius). But this More

MOUNTAIN VIEW, Calif. — Humanity must act now if it hopes to stave off the worst impacts of climate change, NASA chief Charles Bolden says. On the 1950 map, only a small corner of the southwestern U.S. blushes dark red, indicating average July temperatures of at least 105 degrees Fahrenheit (41 degrees Celsius). But this More