1 00:00:00,080 --> 00:00:02,080 Speaker 1: This episode of brain Stuff is brought to you by 2 00:00:02,120 --> 00:00:05,519 Speaker 1: Linda dot Com. Linda dot com offers thousands of engaging, 3 00:00:05,559 --> 00:00:08,760 Speaker 1: easy to follow video tutorials taught by industry experts to 4 00:00:08,800 --> 00:00:12,440 Speaker 1: help you learn software, creative and business skills. Membership starts 5 00:00:12,440 --> 00:00:16,000 Speaker 1: at twenty five a month and provides unlimited seven access. 6 00:00:16,120 --> 00:00:18,720 Speaker 1: Try Linda dot Com free for seven days by visiting 7 00:00:18,840 --> 00:00:22,960 Speaker 1: Linda dot com slash brain Stuff. Welcome to brain Stuff 8 00:00:23,079 --> 00:00:33,680 Speaker 1: from house stuff works dot com, where smart happens. Hi 9 00:00:33,760 --> 00:00:36,840 Speaker 1: am our brain with today's question. If the polar ice 10 00:00:36,960 --> 00:00:41,640 Speaker 1: caps melted, how much would the oceans actually rise? You 11 00:00:41,680 --> 00:00:44,839 Speaker 1: may have heard about global warming. It seems that in 12 00:00:44,880 --> 00:00:48,519 Speaker 1: the last hundred years, the Earth's temperature has increased by 13 00:00:48,560 --> 00:00:52,680 Speaker 1: about half a degree celsius. This may not sound like much, 14 00:00:52,720 --> 00:00:55,000 Speaker 1: but even half a degree can have an effect on 15 00:00:55,040 --> 00:00:59,360 Speaker 1: our planet. According to the US Environmental Protection Agency, the 16 00:00:59,480 --> 00:01:02,400 Speaker 1: sea lave All has risen six to eight inches in 17 00:01:02,440 --> 00:01:06,400 Speaker 1: the last one hundred years. This higher temperature may be 18 00:01:06,600 --> 00:01:10,240 Speaker 1: causing some floating icebergs to melt, but this will not 19 00:01:10,360 --> 00:01:14,559 Speaker 1: make the oceans rise. Icebergs are floating chunks of ice. 20 00:01:14,920 --> 00:01:18,240 Speaker 1: In order to float, the iceberg displaces a volume of 21 00:01:18,240 --> 00:01:21,399 Speaker 1: water that has a weight equal to that of the iceberg. 22 00:01:21,760 --> 00:01:25,160 Speaker 1: So when an iceberg melts, nothing happens to sea level, 23 00:01:25,640 --> 00:01:29,160 Speaker 1: but the rising temperature and icebergs could play a small 24 00:01:29,319 --> 00:01:33,160 Speaker 1: role in the rising ocean level. Icebergs are chunks of 25 00:01:33,240 --> 00:01:36,759 Speaker 1: frozen glaciers that break off from land masses and fall 26 00:01:36,800 --> 00:01:40,520 Speaker 1: into the ocean. The rising temperature may be causing more 27 00:01:40,560 --> 00:01:44,880 Speaker 1: icebergs to form by weakening the glaciers, causing more cracks 28 00:01:44,920 --> 00:01:47,880 Speaker 1: and making ice more likely to break off. As soon 29 00:01:47,920 --> 00:01:50,760 Speaker 1: as the ice falls into the ocean, the ocean rises 30 00:01:50,800 --> 00:01:55,000 Speaker 1: a little bit. If the rising temperature affects glaciers and icebergs, 31 00:01:55,040 --> 00:01:57,760 Speaker 1: could the polar ice caps be in danger of melting 32 00:01:57,800 --> 00:02:01,520 Speaker 1: and causing the oceans to rise even more. This could happen, 33 00:02:01,680 --> 00:02:05,400 Speaker 1: but no one knows when. The main ice covered land 34 00:02:05,440 --> 00:02:08,760 Speaker 1: mass is Antarctica at the South Pole, with about nine 35 00:02:09,280 --> 00:02:12,959 Speaker 1: of the world's ice. Antarctica is covered with ice and 36 00:02:13,160 --> 00:02:16,600 Speaker 1: average of two thousand, one hundred thirty three meters or 37 00:02:16,760 --> 00:02:20,639 Speaker 1: seven thousand feet thick, more than a mile. In other words, 38 00:02:20,760 --> 00:02:24,239 Speaker 1: if all of the Antarctic ice melted, sea levels around 39 00:02:24,280 --> 00:02:28,280 Speaker 1: the world would rise about sixty one or two hundred feet, 40 00:02:28,680 --> 00:02:33,000 Speaker 1: but The average temperature in Antarctica is minus thirty seven 41 00:02:33,000 --> 00:02:36,360 Speaker 1: degrees celsius, so the ice there is in no danger 42 00:02:36,400 --> 00:02:39,799 Speaker 1: of melting. In fact, in most parts of the continent 43 00:02:39,919 --> 00:02:43,079 Speaker 1: it never gets above freezing any time during the year. 44 00:02:43,840 --> 00:02:45,919 Speaker 1: At the other end of the world, the North Pole, 45 00:02:46,000 --> 00:02:48,360 Speaker 1: the ice is not nearly as thick as at the 46 00:02:48,400 --> 00:02:52,200 Speaker 1: South Pole. The ice floats on the Arctic Ocean. If 47 00:02:52,200 --> 00:02:55,919 Speaker 1: it melted, sea levels wouldn't really be affected. There is 48 00:02:55,960 --> 00:02:59,280 Speaker 1: a significant amount of ice covering Greenland, which would add 49 00:02:59,280 --> 00:03:02,240 Speaker 1: another seven meters or twenty feet to the oceans if 50 00:03:02,280 --> 00:03:06,560 Speaker 1: it melted. Because Greenland is closer to the equator than Antarctica, 51 00:03:06,720 --> 00:03:09,560 Speaker 1: the temperatures there are higher, so the ice is more 52 00:03:09,600 --> 00:03:13,040 Speaker 1: likely to melt, but there might be a less dramatic 53 00:03:13,160 --> 00:03:16,560 Speaker 1: reason than the polar ice caps melting. For the higher 54 00:03:16,600 --> 00:03:20,080 Speaker 1: ocean levels. The higher temperature of the water is actually 55 00:03:20,120 --> 00:03:24,640 Speaker 1: having an effect. Water is most dense at four degrees celsius. 56 00:03:25,080 --> 00:03:28,720 Speaker 1: Above and below this temperature, the density of water decreases. 57 00:03:29,080 --> 00:03:33,400 Speaker 1: The same weight of water occupies a bigger space, so 58 00:03:33,600 --> 00:03:37,240 Speaker 1: as the overall temperature of the water increases, it naturally 59 00:03:37,280 --> 00:03:42,280 Speaker 1: expands a little, making the oceans rise. Scientists have tried 60 00:03:42,320 --> 00:03:45,200 Speaker 1: to predict what the sea level will be in the year. 61 00:03:46,840 --> 00:03:50,440 Speaker 1: Different scientists come up with different predictions, but in general 62 00:03:50,720 --> 00:03:54,280 Speaker 1: they estimate that the sea will rise fifty centimeters or 63 00:03:54,280 --> 00:03:58,080 Speaker 1: twenty inches, with the lowest estimates in the fifteen centimeter 64 00:03:58,280 --> 00:04:02,480 Speaker 1: or six inch range and the higher in the centimeter 65 00:04:02,720 --> 00:04:06,040 Speaker 1: or thirty seven inch range. The rise will come from 66 00:04:06,120 --> 00:04:09,560 Speaker 1: thermal expansion of the ocean and from melting glaciers and 67 00:04:09,600 --> 00:04:13,280 Speaker 1: ice sheets. Twenty inches is no small amount. It could 68 00:04:13,280 --> 00:04:18,160 Speaker 1: have a big effect on coastal cities, especially during storm 69 00:04:18,240 --> 00:04:21,120 Speaker 1: Do you have any ideas or suggestions for this podcast? 70 00:04:21,520 --> 00:04:24,160 Speaker 1: If so, please send me an email at podcast at 71 00:04:24,200 --> 00:04:26,920 Speaker 1: how stuff works dot com. For more on this and 72 00:04:26,960 --> 00:04:29,360 Speaker 1: thousands of other topics, go to how stuff works dot 73 00:04:29,400 --> 00:04:32,200 Speaker 1: com and be sure to check out the brain stuff 74 00:04:32,240 --> 00:04:34,719 Speaker 1: blog on the house stuff works dot com home page. 75 00:04:38,360 --> 00:04:41,640 Speaker 1: Audible dot com is the leading provider of downloadable digital 76 00:04:41,680 --> 00:04:45,360 Speaker 1: audio books and spoken word entertainment. 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