Sunday, 28 March 2010

Climate Change causes sea level rise

Climate change is a change in the statistical distribution of weather over periods of time that

range from decades to millions of years.It can be a change in the average weather or a change

in the distribution of weather events around an average (for example, greater or fewer extreme

weather events). Climate change may be limited to a specific region, or may occur across the

whole Earth.

Global sea level change for much of the last century has generally been estimated using tide

gauge measurements collated over long periods of time to give a long-term average. More

recently, altimeter measurements — in combination with accurately determined satellite orbits

— have provided an improved measurement of global sea level change.

Current sea level rise has occurred at a mean rate of 1.8 mm per year for the past century, and

more recently, during the satellite era of sea level measurement, at rates estimated near 2.8 ±

0.4 to 3.1 ± 0.7 mm per year (1993-2003). Current sea level rise is due significantly to global

warming, which will increase sea level over the coming century and longer periods. Increasing

temperatures result in sea level rise by the thermal expansion of water and through the

addition of water to the oceans from the melting of continental ice sheets.At the end of the

20th century, thermal expansion and melting of land ice contributed roughly equally to sea

level rise, while thermal expansion is expected to contribute more than half the rise in the

upcoming century.

Climate change and increased atmospheric temperatures are predicted to cause a significant rise

in sea level over the next 100-200 years. Scenarios that take into account rapid melting of the

Greenland Ice Sheet and West Antarctic Ice Shelf warn of sea level rise of greater than 20 ft

(6 meters) over the next couple centuries.

This animation shows what that level of rise would (which will happen over a long period of

time) might look like over a couple seconds.

It uses very course scale global elevation data to visualize a rising sea affect and should NOT

be considered highly accurate.

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