WEBVTT FILE 1 00:00:01.070 --> 00:00:05.070 2 00:00:05.070 --> 00:00:09.070 2018 was the fourth hottest year on record. 3 00:00:09.070 --> 00:00:13.000 4 00:00:13.000 --> 00:00:17.070 Earth has been warming up for decades. 5 00:00:17.070 --> 00:00:21.070 6 00:00:21.070 --> 00:00:25.000 7 00:00:25.000 --> 00:00:29.000 The last five years are the hottest five years on record… 8 00:00:29.000 --> 00:00:33.070 9 00:00:33.070 --> 00:00:37.070 And the last four were all more than 1 degree Celsius 10 00:00:37.070 --> 00:00:41.000 warmer than the 19th Century average. 11 00:00:41.000 --> 00:00:45.000 A warmer climate contributes to… 12 00:00:45.000 --> 00:00:49.000 melting polar ice and mountain glaciers, 13 00:00:49.000 --> 00:00:53.000 rising sea levels, 14 00:00:53.000 --> 00:00:57.000 more severe droughts, 15 00:00:57.000 --> 00:01:01.000 longer fire seasons. 16 00:01:01.000 --> 00:01:05.000 17 00:01:05.000 --> 00:01:09.070 NASA and NOAA work together to study the temperature from weather stations, 18 00:01:09.070 --> 00:01:13.070 ships and buoys in the ocean, and Antarctic research stations. 19 00:01:13.070 --> 00:01:17.070 20 00:01:17.070 --> 00:01:22.316 [NASA]