The global average sea level has increased 8 inches since 1880. Several locations along the East Coast and Gulf of Mexico have experienced more than 8 inches of local sea level rise in only the past 50 years.
In parts of the East Coast and Gulf regions, land is subsiding, which allows the ocean to penetrate farther inland.
Shrinking land ice — glaciers, ice caps, and ice sheets — contributed about half of the total global sea level rise between 1972 and 2008, but its contribution has been increasing since the early 1990s as the pace of ice loss has accelerated.
Recent studies suggest that land ice loss added nearly half an inch to global sea level from 2003 to 2007, contributing 75 to 80 percent of the total increase during that period
Even if global warming emissions were to drop to zero by 2016, sea level will continue to rise in the coming decades as oceans and land ice adjust to the changes we have already made to the atmosphere.
Antarctica is covered by vast ice sheets that sit atop the continent. Many of these ice sheets flow, gradually, toward the ocean, where they form ice shelves that float on the water. Over time, chunks of these ice shelves break off — or "calve" — to form icebergs.
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