We know the exact rate at which seawater expands with temperature, and the expected increase in sea level calculated from the observed increase in temperature matches the observed rate of increase of sea level.

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IPCC's worst-case scenario, which is about a 7 degree Fahrenheit rise in temperature, shows a global sea level gain of 10 to 23 inches.

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Such increased summer melting has an immediate local temperature effect, and it also will affect sea level.

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They adjust the temperature and pressure of the mix to mimic conditions at various heights above sea level.

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The IPCC Panel's near-consensus was that human activity is having some discernible impact on climate, and that by 2100, a warming earth could result in more frequent storms and droughts, sea level rise of up to three feet, and up to six degrees F. in temperature rise.

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If global temperature rises by about 1 degree Fahrenheit in the next century, scientists estimate the sea level will rise seven to 15 inches.

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