What is causing sea-level rise?
Human activity is having an effect on the rate of change in the relative concentration of gases within the earth’s atmosphere (Garnaut 2008). These changes affect the climate and are currently resulting in the global climate warming. Current sea-level rise is due to thermal expansion (water expanding as it warms) and the melting of land-based ice sheets and glaciers (IPCC 2007b). Thermal expansion contributes up to 75 per cent of sea-level rise with the balance coming from land-based ice sheet melt such as glaciers. Accelerated land ice melt at Greenland and Antarctica, due to scaled up ice sheet discharge, could add up to a further 20 cm to sea-level rise. (IPCC 2007b). At a regional scale, sea-level rise also depends on land movement, ocean currents and climatic conditions (IPCC 2007a, Bureau of Meteorology 2007).
