Sea levels threaten 250,000 homes in Australia

Lenore Taylor, The Australian 14 Nov 09;

Almost 250,000 homes, now worth up to $63 billion, will be "at risk of inundation" by the end of the century, under "worst-case but plausible" predictions of rising sea levels.

The study -- released ahead of the crucial Senate vote on Labor's emissions trading scheme -- modelled the effect of a 1.1m sea-level rise on cities and towns around Australia.

This is a higher level than the 79cm end-of-century rise predicted by the last Intergovernmental Panel on Climate Change, but in the mid-range of some subsequently published research.

It found between 157,000 and 247,000 homes "at risk of inundation" -- meaning they would be permanently flooded or frequently flooded by storm surges or king tides -- with hospitals, water-treatment plants and other public buildings also found to be at risk.

Even Sydney airport would be at "increased risk" of inundation, according to the study, written by the Department of Climate Change with input from CSIRO, Geosciences Australia and scores of academics.

The study -- which models possible risks down to township and local government areas complete with aerial photographs of towns showing the possible inundation -- appears timed to give the public a sharp reminder of the possible dangers of climate change.

It also increases pressure on the opposition as the government's ETS bill is brought back to parliament next week.

It found NSW had "the greatest exposure", with between 40,800 and 62,400 homes at risk, followed by Queensland (35,900 to 56,900), Victoria (27,600 to 44,600), South Australia (25,200 to 43,000) and Western Australia (18,700 to 28,000).

Within each state, it identified the local government areas where property was most "at risk" -- for NSW, Lake Macquarie, Wyong, Gosford, Wollongong, Shoalhaven and Rockdale; for Queensland, Moreton Bay, Mackay, the Gold Coast, Fraser Coast, Bundaberg and the Sunshine Coast; and for Victoria, Kingston, Geelong, Wellington and Port Phillip.

The study says that "based on the recent science 1.1m was selected as a plausible value for sea-level rise for this risk assessment. It is important to note that the purpose of a risk assessment is to identify areas of risk and therefore plausible worse-case scenarios need to be considered."

Andrew Ash, director of the CSIRO climate-change adaption flagship, said the 1.1m sea-level rise was "certainly plausible".

"As things stand, the only variation will be exactly when we reach that level," Dr Ash said.

Given the study was meant to help government planning decisions, it was therefore "both plausible and appropriate" to model a 1.1m rise.

As well as the threat of inundation, the study calculates how many buildings are under threat from "soft" erodable shorelines.

250,000 homes 'at risk' from rising seas
Sarah Clarke and staff, ABC 14 Nov 09;

A new report has warned that up to 250,000 homes around Australia will be inundated due to climate change by the turn of the century.

The Federal Government report titled Climate Change Risks to Australia's Coast is the most comprehensive assessment to date, taking into account a projected 1.1-metre rise in sea level and an increasing risk of extreme weather events like tidal and storm surges.

Up to $63 billion worth of residential property faces inundation, as well as 120 ports, some airports - including Brisbane and Sydney - and 1,800 bridges.

Rising sea levels also threaten the five power stations and three water treatment plants located within 200 metres of Australia's coastline.

Scientist Tim Flannery has been appointed to chair the next phase of this report and he says the graphic assessment needs to be treated seriously.

"If you get a six-metre sea level surge with a cyclone on a place like the Gold Coast you have got very serious trouble," he said.

"The thing about sea level rise is that its inexorable, it strikes at all coasts at the same time.

"Anyone who thinks we we may be able to adapt to this, I beg you to think again, because the scale at which you would have to build sea walls or coastal defence barriers is so massive."

National approach

Climate Change Minister Penny Wong says she too is concerned by this assessment and a national emergency plan needs to be put in place.

She says from now on, every planning and development approval must consider climate change as one of the greatest risks.

"That's going to take information, it's going to take work, it's going to take coordination," she said.

"This is a very important step in providing the information Australia needs."

Nick Harvey from the University of Adelaide was one of the eight scientists contributing to another report, from the Intergovernmental Panel on Climate Change, that assessed Australia's climate change risks.

He argues the key to reducing the danger is putting in place a national approach.

"We definitely need a national plan but you also do need to look at regional variations in sea level around the coast, and they will affect different frequencies," he said.

"For example, if we're talking about the return frequency of the, say, the one-in-100-year storm, that is going to affect different parts of the country in a different manner.

"I think in Sydney there were some major storms a while ago and if you're looking at the one-in-100-year event that's going to become far more frequent by the year 2100."

The report warns that New South Wales will have the "greatest exposure" to sea level rises, with up to 60,000 homes at risk.

The State Water Minister, Phil Costa, says his Government is committed to a national response to the threat.

"It's catastrophic. We've already begun the process of ensuring that the planning regime is working towards the potential of sea level rise, so we have time, we can do it and we can only do it as a nation," he said.

"We can't have just one state dealing with this particularly difficult time that's ahead of us - we all have to work together."

In Victoria, up to 45,000 residential buildings are at risk of being inundated by rising sea levels, with 70 per cent of those located in the Kingston, Hobsons Bay, Greater Geelong, Wellington and Port Phillip local government areas.

It puts the current value of those buildings at around $10.3 billion, with nearly 5,000 structures located within 110 metres of soft, erodible shorelines.

The report also says up to 57,000 residential buildings in Queensland could be at risk because of the sea level rise.

It found the areas most at risk of inundation were Moreton Bay, Mackay, the Fraser Coast, Bundaberg and the Gold and Sunshine Coasts.

In South Australia, as many as 43,00 homes may be at risk. Nearly half are within the Port Adelaide Enfield and Charles Sturt council areas.

Senator Wong also used today's launch of the report to take a swipe at climate change sceptics in the Coalition, saying the science in the report shows that climate change is real.