Sea level changes 'underestimated'

THE speed at which the climate is changing has been significantly underestimated, with thousands of Australian homes potentially at risk from rising sea levels, a conference has heard.

More than 80 per cent of Australians live in the coastal zone, with about 700,000 homes located within 3km of the coast and less than six metres above sea level.

Ports, harbours and airports situated near the ocean are also vulnerable to the immediate effects of climate change, said keynote speaker Jo Mummery.

Speaking on the first day of the Coast to Coast 2008 Conference in Darwin, Dr Mummery said there were "major information gaps'' in Australia.

Preliminary modelling has found that if there is a rise in sea levels, 269,505 houses could be at risk in NSW and 2,875 houses in the NT.

Dr Mummery - from the federal government's Department of Climate Change - said a rise of only one metre could put a number of Gold Coast properties at risk and impact on canal development.

"There are vulnerabilities all around the Australian coastline,'' she said.

"It is an issue of significant magnitude and it does need proper assessment and all governments working together to minimise the risks and ensure there is as little damage as possible.''

But Dr Mummery said initial work on the National Coastal Vulnerability Assessment - to be handed to the federal government at the end of this year - had not taken elevations into account and other scientific factors.

"This really is very early work and many more factors need to be taken into account before we have concrete projections,'' she said.

Although one thing is for certain: "It is going to be a negative story ... leading to damage of assets and loss of value''.

Coast to Coast is the first national conference to address the assessment, monitoring, planning and adaptation for coastal climate change.

Professor Will Steffan, from the Australian National University, said the scientific community had underestimated the speed at which the climate was changing and there could be devastating effects on many low-lying areas in coastal Australia within the next century.

"The evidence over the past 12 to 18 months suggests that we have underestimated how fast this aspect of the earth's system can change,'' he said.

"We see things happening much faster than we thought.''

Prof Steffan, also an adviser to the federal government, said climate change was the "most complex and difficult challenge we have faced as a species''.

"In the 21st century a sea level rise of at least 0.5 metres is a certainty, a rise of 1 to 1.5 metres is more likely while a rise of up to four metres this century is possible,'' he said.

Also this week in Darwin, federal parliament is holding an inquiry into climate change and environmental impacts on coastal communities.

Committee chairwoman Jennie George told today's gathering that Australia was particularly vulnerable.

"The pressing reality of climate change is upon us and all the evidence points to coastlines being the most vulnerable,'' she said, adding that there would be considerable damage to coastal settlements, in particular Aboriginal communities.

Ms George said it was time for the government to act "decisively and without hesitation'' on the "toughest issue facing our generation''.