There’s a long history of adaptation on the Queensland coast — but our changing climate could soon make it harder to get a mortgage there.

Crouched on a sand flat, fringed by mangroves and bush, Clinton Brewer points toward the river mouth and out to the ocean beyond.

"Ten thousand years ago our beach was 30 to 40 kilometres that way," he says.

The continental shelf off the Gold Coast was largely exposed during the last Ice Age, when sea levels were as much as 125 metres lower than they are today.

"Slowly, it took several thousand years for the water to come in; you've got the sea levels rising to where they are right now," Clinton says.

That's where this place — Tallebudgera, behind Burleigh Heads on the Gold Coast — got its name, he says.

"Different families have different [definitions], but from my line, Tallebudgera means 'lots of rotting logs' … it's linked to climate change." 

He points out a midden — a bundelbah — on the side of the track.

"That shell— one of my great, great grandparents had that in his or her mouth and she spat it out probably 500 years ago. So that's my connection with that history."

When Europeans colonised south-east Queensland, the Yugambeh people were forced off their lands, often into missions where speaking their language and practising culture were suppressed.

Many words were lost, but Clinton is one of a number of people working to preserve and restore his language and with it, his saltwater country — his biren jagun.

A few hundred metres behind Clinton though, the constant hum of cars on the highway is a distant reminder that his saltwater country is sandwiched between the ocean and the greater Gold Coast.

If the ocean rises further, something's got to give.

Investors driving prices sky high

On a cold day in Melbourne, Hannah sits with her laptop open to a popular real estate website.

Panels display houses around Cairns in tropical far north Queensland that she's thinking of putting an offer on.

A quick phone call to the real estate agent, though, and she's back to square one.

"You've got these incredibly high rental prices now, that tenants are simply willing to pay to keep a roof over their heads," she says.

"[So] investors are unfortunately swooping in from down south … and are now outbidding us by tens of thousands."

Hannah is originally from Cairns. She wants to move back because it's more affordable than the big cities, and so she can be close to family.

She also says the bushfires during the Black Summer have put her off staying in Melbourne long term.

Unlike Hannah, Amy* has managed to put in a successful bid on a house in Burleigh on the Gold Coast. It's a low-set brick house on a slab near the canals.

Like Hannah, Amy says the market was incredibly hard to get into.

"It's been really difficult to find something new," she says.

"There's a lot of competition and the cheaper houses are snapped up at a bit of a premium that is out of reach for most people."

Banks 'could begin refusing mortgages'

Karl Mallon is the chief executive officer of Climate Valuation, a company that assesses the future risk to houses and property from climate change.

As a case study, Karl's company has agreed to perform an assessment of Amy's new home and a couple of Hannah's prospective houses.

They'll examine the properties as they would for an insurance company or bank — and let us know whether they're in the clear, or if they're at risk of becoming uninsurable or worse.

We've used a pseudonym for Amy, in case the results of the assessment affect the value of her home.

We'll get to those results shortly.

Karl says many home buyers don't realise just how seriously lenders and insurers are taking climate risk.

For places that will be hit by rising seas, bushfires, or other extremes, he says the problems are going to set in long before most are physically impacted.

"The reason I say that is because we work for a lot of them.

"And we have to give them the unvarnished view of which properties are a material risk to their portfolios."

The Insurance Council of Australia is also taking this issue seriously.

"At present no region in Australia is uninsurable. However, it is possible some regions may become difficult to insure in the future unless governments invest in appropriate physical mitigation and adaptation strategies," it said in a statement.

A 'quite serious' chain of events

When Karl's company assesses a property, the results fall into three categories: low, medium and high risk. Properties in the high risk category may be uninsurable without mitigation measures.

But rather than telling people that "the sky is falling in", Karl says nine out of 10 properties are fine.

"One in 10 we're saying have got some problems and one in 20 have got quite serious issues, where we're saying: that property, if it's not already uninsurable, it's going to be uninsurable soon.

The Australia Talks National Survey 2021 grouped Australian attitudes toward climate change by electorate and found regional Queenslanders are some of the least likely to say climate change is a problem for them personally, or Australia generally.

Electorates on the Gold Coast and in far north Queensland ranked among the lowest in Australia for these concerns.

In that sense, Hannah and Amy are exceptions. They both say climate change is an important issue for them and for Australia.

Hannah says she'll use the assessments to help inform her house purchase decision.

But Amy says when she bought her property, the market was too competitive to be choosy.

That's despite being aware there may be some issues with her new house in future.

"I guess for us, knowing that we want to keep living in this area, we just couldn't really be picky about looking at elevation," Amy says.

'We've been attacked by the ocean'

Rodger Tomlinson has served as the Gold Coast City Council professor of coastal management and is the foundation director of the Griffith Centre for Coastal Management.

He says Miami Beach in Florida is an example of where the council is being proactive in adapting to climate change.

One-time Miami Beach mayor Philip Levine has described sea level rise as like "World War II".

Miami has already spent hundreds of millions of dollars raising roads, improving its sewerage network and installing a series of powerful pumps to remove ocean surges from the streets.

And it's only going to get more expensive. The bill is expected to top $US4 billion by 2060.

But Karl Mallon says people informing themselves of the risks to property may actually drive a market for resilient infrastructure.

"Thousands of properties are being checked every year, so we know home buyers are paying attention [and] we think it's only a matter of time before the values start to reflect that," he says.

He says Climate Valuation has had "very encouraging" discussions with banks about lending money to homeowners to make their houses more resilient to things like seawater inundation.

"That's a win for everybody – the home buyer is a winner, the insurer is a winner, the bank's a winner, and even the local government, because it protects property values and wealth in the area.

"So there are ways forward."

'An island by the end of the century'

In front of her computer in sunny far north Queensland, Hannah has escaped the Melbourne cold for a wedding.

Of the three properties she was looking at, two have come back with positive results. 

"It's reassuring that the areas that I am looking in and would prefer to be investing in are receiving a triple A or AAB rating, which is fantastic," Hannah says.

The third will move into the worst category toward the end of the century, with sea-level rise forecast to reach the property around 2090.

Again, lending may become an issue well before then.

"The coastal inundation was something that I wasn't expecting to be that bad by that point in time. That's effectively my children's generation," Hannah says.

"[And] just because [a house] has an A rating in 2100, doesn't necessarily mean that Cairns will exist as it does today.

"That's the other side of it. It's a bit of an eye-opener.

"People will have to adapt, unfortunately."

Hannah says going through the process has changed the way she's looking at the bigger picture.

"I literally walked up to a block this morning, and the top of the beach rises to a bit of a cliff. The blocks are at maybe 42 metres above sea level, so they're in a safe spot," she says.

"But the point my partner raised after looking at these reports was that the rest of the beach, the whole road into this area is sitting at 1.2 metres above sea level. It'll be an island by the end of the century."

More questions than answers

Meanwhile, Amy's misgivings about her place have proven to be well founded.

The assessment has found her house is already in the most at-risk category.

"I understood the Gold Coast is quite low lying in relation to sea level," Amy says.

But she says the report leaves her with more questions than answers. She'd like to see the potential adaptation strategies broken down according to who has the responsibility to implement them.

"I guess if I was going to do a report like this, I'd probably [break it up into] 'these are the things that are local government responsibility, these are the things that are home-owner responsibility, and these are the things where you should probably elect a better government'," she says.

The report also shows the flood risk to her property will plateau during the century, which the authors put down to regional climate variability, but that extreme flood levels could even have impacts on Amy's roof.

"How can we think about the floor covering … or is it even worth thinking about it – if they’re saying my roof structure is going to be impacted by riverine flooding?" she says.

She says if there's a flood to that extent, then most of the Gold Coast will also go under — one of the many things she weighed up with her partner before they decided to stay there.

"It'd be a disaster zone. Then you're coming down to the choice of, are you relocating?

"In some ways, we're just making a decision that we'll stay where we are as long as that remains viable."

There are thousands of homeowners up and down the Queensland coast in the same position as Amy.

Karl says the gamble starts once insurance becomes unaffordable.

"I've got testimony after testimony of people who've said, 'look, it just got to the point where I couldn't afford [the insurance] anymore'. And then they ticked a box which said, 'I don't want flood cover'.

He says raising houses on stumps or building flood barriers around them is one option for making them more resilient, but it's likely some low-lying areas will become unliveable over the next century.

Professor Tomlinson agrees that infrastructure can only hold back the ocean so much.

"We've got to get climate change under control."

'Nature will find a way to humble you'

Back on the sand flats of Tallebudgera Creek, the sun is rising higher in the sky.

The tide is near low.

Birds are swooping the water in the distance. Others are running across the sand, their long skinny legs a blur underneath them.

Magpie larks start screeching and the herons take off down the creek.

"We've got a bird of prey around. See that? They're all taking off," Clinton says.

A few seconds later, a huge white-bellied sea eagle bombs from the sky and grabs a mullet from the water.

"The environment is always telling us what's going on.

"If you're not humble, [nature] will find a way to humble you."

He says his saltwater country is full of remnants, like the middens, from his ancestors.

But he also acknowledges that past sea-level rise has probably buried thousands of sites before.

He says culture and people need to be able to change and adapt as the environment changes.

"Tradition is not the worship of ashes, but the preservation of fire," he says.

"Our dances and song and history, we create new ones, to reflect our context, the landscape that we're in and to further understand our dreaming and connection to all this.

"We must be like the sea eagle, or the possum, or the guruhman; the kangaroo, or the gil gil; the brolga, or the little microbes or the worms.

"We must adapt."

Credits: 

Reporting: Nick Kilvert

Illustrations: Stacy Gougoulis

Graphics: Climate Valuation

Digital production: Nick Kilvert and Joel Zander

Editor: Joel Zander

ABC Science editor: Jonathan Webb