1 00:00:00,190 --> 00:00:04,250 2 00:00:04,250 --> 00:00:08,440 NASA's DC-8 plane carried instruments to measure carbon dioxide and methane as it spiraled down over Kotzebue, Alaska. 3 00:00:08,440 --> 00:00:12,630 4 00:00:12,630 --> 00:00:16,820 5 00:00:16,820 --> 00:00:21,020 6 00:00:21,020 --> 00:00:25,220 7 00:00:25,220 --> 00:00:29,230 8 00:00:29,230 --> 00:00:33,270 9 00:00:33,270 --> 00:00:36,253