Sea level rise is a phenomenon caused by the melting of polar and alpine glaciers, the expansion of water due to global warming, and on the geologic scale, by changes in the relative amount of sediment in ocean basins. The fact that sea level has risen at a relatively rapid rate over the last century, is frequently used as supporting evidence that the activities of humans are changing the world environment.

The Controversy

Many researchers believe that rising average sea levels are further evidence that global warming has been significantly influenced by human activity. They also contend that global warming will cause additional sea level rise, possibly wiping out shore-based communities.

Most climatologists argue that rising atmospheric temperatures are currently causing polar and alpine glaciers to melt and water in the oceans to expand. Others assert that the increased temperatures cause water to evaporate, leading to increased cloud cover and precipitation. Some of this precipitation, they contend, inevitably becomes incorporated into glaciers and that any further increase in global average temperatures will likely lead to a decrease in sea level. See http://sepp.org/scirsrch/slr-agu.html.

The Effects of Current Sea Level Rise

Rising sea levels have forced the evacuation of Tuvalu, an island nation of 11,000 people in the South Pacific, North of Fiji. The Tuvaluan government announced the evacuation in 2001.