WEBVTT 00:00:01.896 --> 00:00:05.216 Why is 1.5 degrees such a big deal? 00:00:05.240 --> 00:00:10.146 Because to warm our entire planet up by 1.5 degrees Celsius 00:00:10.170 --> 00:00:12.478 requires a lot of heat. 00:00:12.502 --> 00:00:16.156 All this extra heat melts glaciers, which raise sea levels. 00:00:16.180 --> 00:00:19.726 If the ice sheets of Antarctica and Greenland melt completely, 00:00:19.750 --> 00:00:22.478 millions of people's homes will be under water. 00:00:22.799 --> 00:00:25.176 The extra heat also intensifies weather, 00:00:25.200 --> 00:00:28.070 making wet places wetter, dry places drier 00:00:28.094 --> 00:00:30.616 and increasing the ferocity of storms. 00:00:30.640 --> 00:00:34.716 That 1.5-degree increase also won't be distributed evenly. 00:00:34.740 --> 00:00:38.296 The coldest nights in the Arctic might get 10 degrees warmer. 00:00:38.320 --> 00:00:41.602 The warmest days in Mumbai might get five degrees hotter. 00:00:41.626 --> 00:00:44.476 Over the past 10,000 years, we've been lucky. 00:00:44.500 --> 00:00:48.236 Earth's climate was stable and our civilizations flourished. 00:00:48.260 --> 00:00:53.696 But as our climate gets more unstable, so will our economies and our societies. 00:00:53.720 --> 00:00:55.153 We'll all suffer, 00:00:55.177 --> 00:00:57.638 and the vulnerable will be hit hardest, 00:00:57.662 --> 00:00:59.415 unless we act now. 00:01:02.363 --> 00:01:03.949 [Countdown 00:01:03.973 --> 00:01:06.753 Take action on climate change at Countdown.ted.com]