Victoria gets trillion-dollar bad news: sea level rises will swamp parts of the state

New scientific and economic research for the Andrews government warns of the grave risk of rising seas along the Victorian coast including trillions of dollars of damage to homes and other assets, if global warming is not slowed and planned for.

The research will add pressure on the government to further restrict development on the coast by lifting its current sea level rise planning benchmark of 0.8 metres by 2100, and to start planning for the “retreat” of some low-lying coastal towns.

Rex Grady near the barrier erected by the Port Fairy golf club to protect the course from rising seas.Credit: James Mepham

University of Melbourne professor of environmental economics Tom Kompas, is in the early stages of a risk analysis for the government and its advisory body, the Victorian Marine and Coastal Council.

He said sea level rise was the “biggest risk to the Australian economy from climate change” – bigger even than bushfires, heat stress and the damage to agriculture.

“This will certainly be bigger than an annual COVID-19 hit to the economy,” he said, with early findings pointing to damages in the trillions of dollars without adequate intervention and planning.

But the warning also presents a quandary for a government which sees construction as key to the state’s COVID-19 recovery, and as as many Melburnians seek to relocate out of the city in the wake of COVID-19.

The current 0.8 metre projected rise is consistent with the now dated projections of the Intergovernmental Panel on Climate Change (IPCC) and, since 2008, has guided where development and construction can occur along Victoria’s 2500-kilometre coastline.

The 0.8 metre figure does not take into account the projected melting of the Greenland and Antarctic glaciers and ice sheets. Updated IPCC projections in 2019 did factor in ice melt and found that inaction on climate change would likely result in a sea level rise of 1.1 metres by 2100 and five metres by 2300.

The CSIRO has provided advice to the government on the IPCC projections translated locally across the Victorian coast. If the government accepts the IPCC’s upper-end projections, as it did in 2008, it would revise its own benchmark to about 1.1 metres by 2100.

Without intervention a 1.1-metre sea level rise would put at risk many areas around Port Phillip Bay but also many much- loved coastal towns such as Port Fairy, Apollo Bay, Inverloch and Lakes Entrance.

On the coast beyond Melbourne where wild seas are a daily reality, many need no more convincing of the reality and danger of climate change-affected sea level rise.

Rex Grady is life member of the Port Fairy golf club whose 18-hole course hugs the rugged coastline of south-western Victoria. “If you slice your ball you go into the water,” he told The Sunday Age with a chuckle.

For years, Mr Grady has helped the club defend the famed 16th fairway, a local inundation weak spot on a dune that also protects the low-lying Port Fairy from an advancing ocean.

Over three decades about 17 metres of sand dune has been lost to the sea; the recession has sped up over the last 15 years.

Parks Victoria built two fences that were washed away. “Then the council built a very substantial fence that lasted three weeks,” said Mr Grady.

More recently the retired beef and sheep farmer tractored in about 50 large square hay bales to help protect the dune, a suitably rural and effective approach to coastal protection. For now.

Mr Grady is no doubt that the hay bales are temporary and that the next time a king tide coincides with a big storm, the bales will be gone.

Years ago he was wary when scientists started talking about climate change. But after years observing changing weather patterns on his farm, and the mounting threat to his beloved golf course from the sea, he changed his mind.

“When you see the power of the sea and the damage it can do in a very short time you’re more likely to say ‘maybe this climate change thing is happening. Maybe it will take a while, but it is happening’.”

The local Moyne Shire agrees. It has jumped ahead of the state government and the IPCC with its own draft coastal strategy that includes a sea level rise benchmark of 1.2 metres rise by 2100.

“The shire knows that at 0.8 of a metre, sea level rise is a massive problem for the town,” said Mr Grady.

“If it goes to 1.2 metres then no need to worry because Port Fairy won’t be there anymore.”

The 16th fairway in Port Fairy.Credit: James Mepham

Some local property owners and developers are unimpressed. The 1.2 metre inundation zone will restrict where new housing can go; one large proposed estate is now in doubt.

Developer Michael Hearn has proposed an 81-lot subdivision on the Princes Highway, Port Fairy to help cater for strong demand for housing in the area.

His planner Steve Myers said the debate around sea level rise at Port Fairy had “slowed” the housing project by years.

He said it was unfair to plan for sea levels at 2100 because 80 years may be longer than the life cycle of homes built in the next few years.

Mr Myers called for a more “creative and adaptive approach to new development” on the coast.

Mr Grady said it would be interesting to see how the state government weighs developer demands against longer-term planning for climate change. “After-all, it always comes down to dollars and cents.”

Those in and around the government who want climate science and long- term planning to prevail in this coastal debate, have struggled to provide their own “dollars and cents”: arguments over sea level rise.

That may soon change with the University of Melbourne ’s research assessing potential damage to an exhaustive list of assets and infrastructure along the coast including public and private property, homes, shops, farms, mines, parks, roads, bush, wetlands and groundwater.

Whether such numbers are enough to convince treasury officials and politicians with shorter-term horizons is yet to be seen. The coastal strategy has been delayed because of COVID-19 and is now not due for completion until mid-year.

By then the government will also have a second and major CSIRO-led research report on coastal hazards for Port Phillip Bay, which is home to 1.3 million people and the Victorian waterway with most to lose if sea level rise is not adequately planned for.

The two CSIRO reports have not yet been officially considered or released.

But government insiders and experts familiar with the bay and climate change expect the research to be a major wake-up call for Melburnians, and the owners and managers of assets ranging from the beach boxes at Brighton and apartments in Elwood to big public assets like the Western Treatment Plant at Werribee.

Brighton bathing boxesCredit: Eddie Jim

The west of the bay from Williamstown to Altona and at Werribee and Geelong is especially vulnerable because of its low-lying character and geomorphology.

The treatment plant - also an internationally-significant wetland and home to nearly 300 bird species - is a major piece of Melbourne public infrastructure. It is of special concern because it cannot be moved.

On Friday, Melbourne Water’s integrated planning manager, Chris Williams, said some parts of the plant were located close to the edge of Port Phillip Bay but that “climate change adaptation planning is part of our day to day work”.

Experts have also highlighted that even where sea walls and other structures have been built in the past, from Williamstown around to St Kilda and down to Beaumaris, many were not engineered with sea level rise in mind and may have to be rebuilt or raised.

Western Treatment Plant wetlands and birds. The plant is declared an internationally-significant wetland and home to nearly 300 bird species.

On Friday, Environment Minister Lily D’Ambrosio would not be drawn on whether the government would take on the new IPCC’s projections as it finalises the coastal strategy in coming months.

But she said the sea level rise benchmark would be updated as necessary and “supported by the best available science and modelling that put global projections into a Victorian context”.

“Our precious coastline is facing significant climate challenges and we’re working hard to address what is a worldwide problem in both the short and long term,” she said.

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