USATODAY: … Sea level has risen nearly 8 inches worldwide since 1880 but, unlike water in a bathtub, it doesn’t rise evenly. In the past 100 years, it has climbed about a foot or more in some U.S. cities because of ocean currents and land subsidence — 11 inches in New York and Boston, 12 in Charleston, 16 in Atlantic City, 18 in Norfolk and 25 in Galveston, Texas, according to a USA TODAY analysis of 2012 tide gauge data collected by the National Oceanic and Atmospheric Administration (NOAA).
How much higher will it go? Scientists don’t know exactly but, depending on fossil fuel emissions, they project global sea level will rise about 1 foot to slightly more than 3 feet (or 39 inches) by 2100, according to this year’s Fifth Assessment Report by the United Nations’ Intergovernmental Panel on Climate Change. NOAA has projected sea level could rise higher, as much as 6½ feet, by century’s end.
Here’s why: As the Earth’s temperature warms, so do the seas. Heat-trapping greenhouse gases cause more land ice (glaciers and ice sheets) to melt and water to expand. Warmer water simply takes up more room than cooler water. Scientists say global warming will be the primary cause of future sea-level rise. Their greatest uncertainty is how quickly the massive West Antarctic ice sheet will melt… (more)
