Dr Ian Allison, Lead Author Chapter 4 Observations – changes in snow, ice and frozen ground. Antarctic Climate and Ecosystem CRC and Australian Antarctic Division.
Global sea level is currently rising at a rate of about 3 mm per year (equivalent to 0.3 m per century) and the IPCC Fourth Assessment Report shows that almost half of this comes from additional water added to the oceans from the melt of land-based glaciers and ice sheets – the rest comes from thermal expansion as the oceans warm. There is evidence that the rate of melt of mountain glaciers, and perhaps also of the Greenland ice sheet, has increased in the last decade or so. Glacier melt and sea level rise as a result of global warming will continue for many centuries, leading to a cumulative sea level rise with societal impact. Globally, one hundred million people live within about one metre of present day sea-level and they will feel the impacts of rising sea-level through changes such as increases in intensity and frequency of storm surges, more erosion, loss of important wetlands and mangroves and coastal ecosystems such as coral reefs. In many dry climates regions, glaciers provide water for agriculture, community water supply, hydroelectricity generation, etc. Disappearance of glaciers will affect the seasonal timing of water availability with consequent socio-economic and ecosystem impacts
Voices from the Southern Ocean