The two causes of sea level rise are thermal expansion as the ocean waters warm and the melting of ice sheets.
Here is a video – a collaborative effort between NASA’s Jet Propulsion Laboratory and the National Oceanic and Atmospheric Administration’s (NOAA) National Ocean Service – that explains sea level rises, its causes and impacts.
The Intergovernmental Panel on Climate Change forecasts that by the end of this century global sea levels could be 0.44 metres higher compared to 1990 levels. This is not a lot if one considers that sea levels rose by 120 metres after the last ice-age (some 20,000 years ago). The melting of the ice sheets is expected to contribute to 50% of the overall rise.
How would sea rise impact on a country like Ireland? Should the Arctic and Antarctic ice sheets melt, sea level could rise by some 80 metres. Ireland – an Iceapelago – would look something like this.