There are many questions surrounding climate change. One big
question is how the changing climate will affect the oceans. The
sea level has been steadily rising since 1900 at a rate of 1 to 2.5
millimeters per year. In fact, since 1992 new methods of satellite
altimetry using the TOPEX/Poseidon satellite indicate a rate of rise
of 3 millimeters per year. The Fourth Assessment Report from
the IPCC states that "there is strong evidence that global sea level
gradually rose in the 20th century and is currently rising at an increased
rate, after a period of little change between AD 0 and AD 1900. Sea level is
projected to rise at an even greater rate in this century. "
- Fourth Assessment Report on
Sea Level Rise
Sea level can rise
by two different mechanisms with respect to climate change. The
first is the expansion of the sea water as the oceans warm due to an
increasing global temperature. The second mechanism is the melting
of ice over land, which then adds water to the ocean. The IPCC Fourth Assessment Report
predicts that total global-average sea level rise from 1990 - 2100
will be 7 - 15 inches (177 - 381 mm) for low emission scenarios and 10 - 23 inches (254 - 584 mm) for high emission scenarios.
This dataset for sea level trends comes from the University of Colorado Sea Level Research Group and highlights the sea level rise trends from 1993-2012. The trends have been determined for only a nineteen-year period, and reflect the impact of decadal scale climate variability on the regional distribution of sea level rise. Additionally, local sea surface height trends and variations are a result of many factors, including (but not limited to) local rise of land height due to tectonic plate activity or loss of heavy ice pressure, thermal expansion of warmer water, and even local wind patterns. Therefore you should consider these effects in interpreting the data.