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