global warming 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 0:59 Runaway zebras corralled in Washington state; one still missing 1:40 Charlie Puth reacts to Taylor Swift's ‘The Tortured Poets Department' name-drop 2:52 Severe weather kills at least 5 as tornadoes rip through Midwest and South 0:48 World Central Kitchen to resume operations in Gaza 8:39 Gina Rodriguez gushes 0ver motherhood with son Charlie
