The Rising Seas by David Schneider - Essay Example

Historical and geologic records indicate that sea level rises and falls continually when measured on a geologic time scale.  Causes of this rising and falling include the thermal expansion of water as it is heated by the atmosphere, increased runoff from terrestrial glaciers that are responding to increased atmospheric temperature and increased discharge of Antarctic ice for the same reason.  The first two causes are presented as being of minimal importance while the focus for the balance of the article was on the Antarctic ice.

The discussion of rapid sea-level rise was first introduced in 1978.  In 1990, the first group of researchers went to Antarctica to specifically study the amount of ice breaking off from the ice sheets.  They were astonished to see the amount of ice breaking free and made some dire predictions concerning sea level rise.  This was the source of much of the alarmist reports concerning sea level rise through the 1990s.  The reality is these first findings and observations had doubt cast upon them almost immediately.  Other researchers in Antarctica noted that they had not been studying the migration of ice long enough to know if what was observed by the first set of scientists was indeed out of the ordinary.  They also noted that despite increased atmospheric temperatures thought the 1990’s, more than average amounts of snow were accumulating at the south pole.

Much of the controversy surrounding sea-level rise stems from the fact that measuring the actual amount of increase is tricky.  The meters that are used to measure the sea are attached to land that is also being lifted up or is subsiding.  According to measurements taken in Scandinavia, the sea level has dropped by 4 mm each year for decades.  In Hawaii, it has increased by 0.5 mm.  New remote sensing satellites have been deployed that should give us a better idea of how much the sea level is rising, or not rising.  This information should be available now because the data has been collected for the past decade.  Detecting sea level rise is tricky enough.  Predicting it is even more difficult.

In the end, the best analysis available seems to indicate that the sea level is rising about 2 mm/year globally.  This has remained constant for a few hundred years apparently.  Even this is hard to pinpoint because the use of coral cores and ice cores must be employed to determine any increase or decrease in seal level rise.  Like all of the other measurements, these two both have high margins of error.  Hopefully, soon enough data will be available so we can predict if the sea level is going to rise as a result of global warming.