June 20, 2017 7:25 am Study: Earth's Killer Heat Waves Will Only Get Worse A new global study says deadly heat waves will grow in frequency, intensity and duration, affecting 75 percent of the world’s population if greenhouse emissions are not reduced. US & World Videos 8:39 Gina Rodriguez gushes 0ver motherhood with son Charlie 2:22 Scarlett Johansson and Colin Jost have date night at White House Correspondents' dinner 2:09 President of MIT calls for shutting down pro-Palestinian encampments 3:57 Pleasant Sunday despite morning showers 1:00 Three dead in apparent murder-suicide in Lowell