NASA, along with NOAA and others, is using satellite observations of the earth's oceans in combination with data from other international sources, to get a better understanding of sea level changes. "In doing so, the agency is hoping to determine more about factors leading to sea level change, indicators of change such as ocean expansion, changes in ice, impoundment of water, and movement of Earth and coastal regions, and how the latest research developments contribute to our knowledge of sea level rise." According to Dr. Eric Rignot of NASA's Jet Propulsion Lab, "the largest likely factor for sea level rise is changes in the amount of ice that covers Earth. Three-fourths of the planets freshwater is stored in glaciers and ice sheets, or about 220 feet of sea level." Rignot was lead author of one of NASA's 2004 studies showing changes in glacier flow after the Larsen B ice shelf broke away from the coast of the Antarctic Penninsula.
The current NASA study has produced imaging, viewable as mpeg animations, showing sea level and sea surface temperature fluctuations. NASA also has a page with links to several papers on "Breakthrough Discoveries in Sea Level Change Research," 2002-2005. (Another good resource is the Wikipedia page on sea level rise.
I heard recently that NASA budget for this particular kind of work - imaging to keep track of environmental change is being drastically cut by the Bush Administration. Makes sense eh? Makes me less interested in funding Mars vanity missions -that's for sure.