WEBVTT FILE 1 00:00:00.040 --> 00:00:04.160 NASA and NOAA have tracked seasonal changes in the hole in the ozone layer over Antarctica since 1985. 2 00:00:04.160 --> 00:00:08.200 3 00:00:08.200 --> 00:00:12.240 4 00:00:12.240 --> 00:00:16.260 Ozone depletion occurs faster in cooler temperatures, so the ozone hole reaches an annual maximum at the end of southern hemisphere winter. 5 00:00:16.260 --> 00:00:20.290 This year, the ozone hole reached its annual maximum on September 11. 6 00:00:20.290 --> 00:00:24.450 7 00:00:24.450 --> 00:00:28.500 It was the smallest maximum since 1988, partly due to warmer global temperatures. 8 00:00:28.500 --> 00:00:32.640 9 00:00:32.640 --> 00:00:36.730 10 00:00:36.730 --> 00:00:37.440