Australian coasts

Each centimetre of sea-level rise will lead to increasing impacts on low-lying coastal land. Modelling predicts the inundation would cause sandy beaches on the Australian coastline to recede by the order of 100 times the vertical sea-level rise. For example, if the sea level rises by a metre, the coastal beaches could retreat by about 100 metres unless some preventative action is taken. Given that about 85 per cent of Australia's population lives within an hour's drive of the coast, this is particularly relevant.

Floods already cause more damage in Australia than any other natural disaster, in terms of cost to the community. CSIRO researchers believe that damage costs associated with coastal flooding would more than double in southern Queensland and northern New South Wales if sea levels were to rise by 40 centimetres.

Low-lying coastal ecosystems, such as the freshwater wetlands that make up about 90 per cent of the coastal zone of Kakadu in the Northern Territory, are also vulnerable. Hundreds of species of birds, reptiles and amphibians depend on these freshwater areas. Intrusion of salt water is already a major management issue in Kakadu. If sea levels around Australia rise by about 50 centimetres, these freshwater wetlands will become saltier. A 1-metre rise in sea level would transform lowland Kakadu almost totally into mangrove forest.

Future planning should take global warming and consequent sea-level rises into consideration. For example, building protective sea walls and restricting coastal development in areas at risk are planning measures that could minimise damage from rising sea levels over the next century.

Source: science.org.au/nova/082/082key.htm