Rising seas to cost Australia $855 billion by 2100. Here’s what’s already happening
The climate crisis will drive $855 billion in damage by the end of the decade as a half-metre sea level rise radically worsens coastal flooding, a new report predicts.
Already, farmers are being forced to pump water from their fields, beloved beaches are being washed away, and people and businesses across the country are rushing to make sure they have back-up power to ensure the next blackout doesn’t leave their basement flooded.
Ex-Tropical Cyclone Alfred carved great chunks out of Gold Coast beaches. Justin McManus
Complicated questions remain about who will foot the massive bills, but the Climate Council, which published the report on Thursday, warns they are “unlikely to be shared equitably”.
“Australia is a coastal nation facing an enormous and rapidly growing economic threat,” the report says.
“The present-value $855 billion price tag laid out in this report is not a distant or hypothetical risk - it is the conservative cost of a future that is already being locked in along our coastline, driven by decades of burning coal, oil and gas.
“Every Australian will pay this bill, whether they live on the beach or not, either through lower economic growth, damaged infrastructure bills or the slow erosion of the coastal communities that define our national identity.”
Farmers such as Robert Quirk are on the front line.
The Tweed Valley cane farmer said water used to drain out of his fields at low tide, but he was now running pumps “much more all year” to stop his field getting waterlogged.
Flooding near the Tweed Valley after Cyclone Alfred. 9News
“People talk about sea level rise like it's coming. Out here it arrived a long time ago, and we're the ones paying to hold it back,” he said.
Clarence Valley grazier Peter Lake said he’d been forced to rethink parts of his practice even though he was well-prepared for floods, moving stock to safe paddocks.
“But that safe ground is shrinking. Every flood eats into a bit more of it, and every year there's less high land to fall back on,” he said.
Climate action needed now
While preparing and adapting will be key, the Climate Council called on governments to act now to reduce emissions instead of “bailing water out of a sinking boat without bothering to patch the leak”.
“One thing is certain. Adapting to sea level rise will be costly, challenging and complex,” the report says.
“Cutting climate pollution more swiftly and deeply will help to avoid some of the worst impacts, costs and complexities associated with adaptation.
“The decisions made by governments and industry over coming years will determine how much worse things get.”
Costs not distributed evenly
The Climate Council says Australian farms, parks, homes, infrastructure and 2 million hectares of land will face flooding this century due to sea level rise.
The total predicted cost due to loss of land and impacts on more than 260,000 properties is about a third of Australia’s current annual economic output and enough to potentially hit GDP by more than 1 per cent. It’s the first time the national damage bill from sea level rise has been tallied.
Flood-affected areas in the Windsor and Pitt Town areas along the Hawkesbury River in 2021. Getty
But the impacts will not be evenly distributed.
Western Australia ($230.5 billion) faces the largest economic losses, followed by Queensland ($214.5 billion), Victoria ($167 billion) and NSW ($150.7 billion).
Queensland (93,157) has the greatest number of properties at risk, followed by NSW (71,210) and Western Australia (51,366).
The Gold Coast alone faces $84.4 billion in projected economic losses. It’s Australia’s most exposed urban area.
The Gold Coast is Australia’s most exposed urban area. AAP
Registered electrician David Sothern said days-long blackouts following powerful storms in 2023 and Cyclone Alfred – the furthest south in 2025 – prompted many people to rethink.
The Level Electrical director, whose business works a lot with solar energy and backup solutions, said the average buyer was looking for cost savings, and, increasingly, power security, rather than trying to be green.
“When people go without power for weeks [at a time] in a matter of like three or four years a couple of times, it makes a big difference,” he told nine.com.au.
“ … it’s front of mind for everyone on the Gold Coast after the last few years.”
Blackouts are a particularly big issue in highrises and apartments with basements, where a cut to power can mean floodgates and dewatering pumps stop working right at the point they’re needed most.
What it’s based on
The Climate Council report is based on research by University of Melbourne Professor Tom Kompas and assumes an "intermediate" scenario with global emissions peaking by about 2040 and declining steeply thereafter.
That would lead to about 2.7 degrees of average global heating and a global average sea level rise of about 55 centimetres, with significant regional variations. The Climate Council says 14 centimetres of sea level rise in Australia is already “locked in” by 2050, regardless of emissions cuts.
People often think about the problem of sea level rise being permanently wiping out low-lying areas, but more frequent flooding and erosion are also huge issues.
The report notes a small increase in sea level rise can allow storm surges and waves to reach much further inland, exponentially increasing the frequency and severity of coastal flooding.
The existing impacts are clear.
In Sydney, the frequency of minor coastal flooding has jumped from 1.6 days a year in 1914 to 7.8. If emissions pushed further into the “high” scenario, it would be expected weekly by 2050 and daily by 2100, caused by tides alone without any storms.
In Sydney, the frequency of minor coastal flooding has jumped from 1.6 days a year in 1914 to 7.8. NSW SES Randwick Unit
Scientists believe every 10 centimetres the sea rises triples the frequency of so-called once-in-a-century flood events, the likes of which have already been hitting more than every 100 years.
In the Victorian town of Inverloch, on the Bass Coast, a surf lifesaving club built in 2010 now relies on sandbags to hold back the tide as the ocean robs about 10 metres of beach a year.
"I have been observing this coastline for many years, and the recent acceleration of erosion has been confronting, watching our beloved beaches wash away,” nearby resident and retired geography teacher Aileen Vening said.
The ocean is robbing about 10 metres of beach a year in Inverloch. The Age
Adapting to and recovering from increased flooding is a complicated and costly matter, particularly given most insurance policies don’t cover “actions of the sea”.
The Climate Council, an Australian body designed to give independent advice on the science of climate change, warns the protection gap will only widen in coastal communities.
It says cutting emissions more swiftly and deeply now will help avoid some of the worst impacts.
“This Parliamentary term key opportunities include closing loopholes in the Safeguard Mechanism and ending billions of dollars in tax breaks for polluting diesel being handed to profitable mining corporations are practical steps that can be taken to help avoid a far more costly, dangerous and irreversible future,” the report urges.
“The science is clear, the economics are stark, and the solutions are within reach. What's needed now is the political will to act.”
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