Speaker 1: This episode of brain Stuff is brought to you by
Speaker 1: Linda dot Com. Linda dot com offers thousands of engaging,
Speaker 1: easy to follow video tutorials taught by industry experts to
Speaker 1: help you learn software, creative and business skills. Membership starts
Speaker 1: at twenty five a month and provides unlimited seven access.
Speaker 1: Try Linda dot Com free for seven days by visiting
Speaker 1: Linda dot com slash brain Stuff. Welcome to brain Stuff
Speaker 1: from house stuff works dot com, where smart happens. Hi
Speaker 1: am our brain with today's question. If the polar ice
Speaker 1: caps melted, how much would the oceans actually rise? You
Speaker 1: may have heard about global warming. It seems that in
Speaker 1: the last hundred years, the Earth's temperature has increased by
Speaker 1: about half a degree celsius. This may not sound like much,
Speaker 1: but even half a degree can have an effect on
Speaker 1: our planet. According to the US Environmental Protection Agency, the
Speaker 1: sea lave All has risen six to eight inches in
Speaker 1: the last one hundred years. This higher temperature may be
Speaker 1: causing some floating icebergs to melt, but this will not
Speaker 1: make the oceans rise. Icebergs are floating chunks of ice.
Speaker 1: In order to float, the iceberg displaces a volume of
Speaker 1: water that has a weight equal to that of the iceberg.
Speaker 1: So when an iceberg melts, nothing happens to sea level,
Speaker 1: but the rising temperature and icebergs could play a small
Speaker 1: role in the rising ocean level. Icebergs are chunks of
Speaker 1: frozen glaciers that break off from land masses and fall
Speaker 1: into the ocean. The rising temperature may be causing more
Speaker 1: icebergs to form by weakening the glaciers, causing more cracks
Speaker 1: and making ice more likely to break off. As soon
Speaker 1: as the ice falls into the ocean, the ocean rises
Speaker 1: a little bit. If the rising temperature affects glaciers and icebergs,
Speaker 1: could the polar ice caps be in danger of melting
Speaker 1: and causing the oceans to rise even more. This could happen,
Speaker 1: but no one knows when. The main ice covered land
Speaker 1: mass is Antarctica at the South Pole, with about nine
Speaker 1: of the world's ice. Antarctica is covered with ice and
Speaker 1: average of two thousand, one hundred thirty three meters or
Speaker 1: seven thousand feet thick, more than a mile. In other words,
Speaker 1: if all of the Antarctic ice melted, sea levels around
Speaker 1: the world would rise about sixty one or two hundred feet,
Speaker 1: but The average temperature in Antarctica is minus thirty seven
Speaker 1: degrees celsius, so the ice there is in no danger
Speaker 1: of melting. In fact, in most parts of the continent
Speaker 1: it never gets above freezing any time during the year.
Speaker 1: At the other end of the world, the North Pole,
Speaker 1: the ice is not nearly as thick as at the
Speaker 1: South Pole. The ice floats on the Arctic Ocean. If
Speaker 1: it melted, sea levels wouldn't really be affected. There is
Speaker 1: a significant amount of ice covering Greenland, which would add
Speaker 1: another seven meters or twenty feet to the oceans if
Speaker 1: it melted. Because Greenland is closer to the equator than Antarctica,
Speaker 1: the temperatures there are higher, so the ice is more
Speaker 1: likely to melt, but there might be a less dramatic
Speaker 1: reason than the polar ice caps melting. For the higher
Speaker 1: ocean levels. The higher temperature of the water is actually
Speaker 1: having an effect. Water is most dense at four degrees celsius.
Speaker 1: Above and below this temperature, the density of water decreases.
Speaker 1: The same weight of water occupies a bigger space, so
Speaker 1: as the overall temperature of the water increases, it naturally
Speaker 1: expands a little, making the oceans rise. Scientists have tried
Speaker 1: to predict what the sea level will be in the year.
Speaker 1: Different scientists come up with different predictions, but in general
Speaker 1: they estimate that the sea will rise fifty centimeters or
Speaker 1: twenty inches, with the lowest estimates in the fifteen centimeter
Speaker 1: or six inch range and the higher in the centimeter
Speaker 1: or thirty seven inch range. The rise will come from
Speaker 1: thermal expansion of the ocean and from melting glaciers and
Speaker 1: ice sheets. Twenty inches is no small amount. It could
Speaker 1: have a big effect on coastal cities, especially during storm
Speaker 1: Do you have any ideas or suggestions for this podcast?
Speaker 1: If so, please send me an email at podcast at
Speaker 1: how stuff works dot com. For more on this and
Speaker 1: thousands of other topics, go to how stuff works dot
Speaker 1: com and be sure to check out the brain stuff
Speaker 1: blog on the house stuff works dot com home page.
Speaker 1: Audible dot com is the leading provider of downloadable digital
Speaker 1: audio books and spoken word entertainment. Audible has over one
Speaker 1: hundred thousand titles to choose from to be downloaded to
Speaker 1: your iPod or MP three player. Go to audible podcast
Speaker 1: dot com slash brain stuff to get a free audio
Speaker 1: book download of your choice when you sign up today.