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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"Every few extra inches of sea level have very significant economic impacts, because they change the sea level, increase flooding and storm damage, " said, Zwally, ICESat Project Scientist.

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Even a small increase in sea level can mean a lot more flooding in a storm, and more frequent floods than in the past.

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It also threatens populations, who can no longer live close to the coastline, and the worry is it is expected to increase due to climate change and sea level rise.

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The result will be an increase in magma production, but not at exactly the same time as the sea level changes.

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