He only moved in seven months ago, but Roly Green has already been forced to clear out the shed in the backyard of his home on the northern Gold Coast.

Key points: The IPCC predicts the seas could rise more than a metre by 2100

The IPCC predicts the seas could rise more than a metre by 2100 Coastal scientist Daniel Harris says that'd impact Gold Coast homes and roads

Coastal scientist Daniel Harris says that'd impact Gold Coast homes and roads Budds Beach will be under threat from king tides when the sea level rises

Mr Green's property at Jacobs Well was one of many across the Gold Coast that flooded when record rainfall drenched the region in February.

Fortunately, the rain did not coincide with a king tide — that would have pushed water levels even higher as drains backed up.

"The water was coming down the street and the drains aren't good enough and so it pooled around [the front of the property] and into the yard," he said.

Fortunately, the house was spared.

Roly Green thought his Jacobs Well house would be above the flood zone. ( ABC News: Dea Clark )

"It's a great house — the only reason I bought this place is because it was a metre off the ground."

But scientists are concerned 1 metre will not be enough to protect Mr Green's house in the future.

Even the most conservative of predictions by the Intergovernmental Panel on Climate Change (IPCC) show global sea levels will rise 30 to 60 centimetres by 2100.

Heavy rain in February flooded Roly Green's backyard in the Gold Coast suburb of Jacobs Well. ( Supplied: Roly Green )

If temperatures climb more than 2 degrees Celsius above pre-industrial levels, the IPCC estimate the sea level rise will blow out to between 60 and 110cm.

In Queensland, several islands in the Torres Strait are particularly vulnerable.

But the problem does not stop there — Port Douglas, Cairns and the Sunshine Coast are also at risk.

'The last line of defence'

Coastal scientist Daniel Harris said parts of Australia's east coast have been identified as global hotspots.

The Gold Coast is of particular concern, given the density of development and population, often in sensitive areas.

"There are a lot of people and infrastructure in very low-lying areas or on top of what used to be dune systems," Dr Harris said.

"It's a massive amount of water that's all of a sudden impacting on the coast, and the beach will respond to that by eroding back towards the dunes, if they're available. If they're not, it will go into homes, infrastructure (and) roads," Dr Harris said.

Dubbed the "last line of defence", a boulder wall concealed behind sand dunes stretches along much of the Gold Coast's 42-kilometre coastline.

The Gold Coast's first seawall was built at Narrowneck to protect the foreshore from erosion. ( ABC News: Dea Clark )

Combined with sand replenishment, the wall is an integral part of Gold Coast beach management.

But without an upgrade, Dr Harris said the seawall might not provide the protection needed.

"With higher sea levels, those defences may start being overtopped, creating damage and a lot of the iconic buildings on the Gold Coast could be at risk," Dr Harris said.

Water across the road at the entrance to Calypso Bay canal development at Jacobs Well on Queensland's northern Gold Coast after record rainfall in February. ( ABC News: Dea Clark )

But he warned there would also be a downside to going higher.

"One of the big things that can happen when you build seawalls on beaches that are eroding is that you can lose the beach," he said.

More than an inconvenience

The impacts will also be felt inland, and areas already prone to flooding face the biggest threat.

Properties near Budds Beach will suffer incursion from king tides as the sea level rises. ( ABC News: Dea Clark )

Budds Beach on the Nerang River in Surfers Paradise is an idyllic sandy retreat.

But on a king tide, water can rise through drains and flood the streets.

Kate Madison, who has owned a cafe in Budds Beach for 20 years, said the flooding was usually just a nuisance.

"All our copper wiring gets impacted [and] it's just you couldn't drive the car through the salty water. I think we all get a bit concerned about that," she said.

Kate Madison says sea level rise will be devastating for properties at Budds Beach. ( ABC News: Dea Clark )

However, a rising sea level will bring more than inconvenience.

"Around here, there's not one property that wouldn't be devastated. There's not one business that wouldn't be devastated," Ms Madison said.

As part of a campaign to raise awareness, local environmental group Gecko engaged a surveyor to map out the impact on Winders Park at Currumbin.

The flood level was calculated by adding 80 centimetres to the highest king tide.

Campaign organiser David Paynter said he was shocked by the result.

"That covers across all the park out onto the road and laps up against the houses on the far side of the road," he said.

David Paynter marks the king tide mark in a Currumbin park with a sea level rise of 80 centimetres. ( ABC News: Dea Clark )

Lois Levy from Gecko said most of the Gold Coast's recreational areas are beside creeks, canals and flood plains.

"They'll probably be underwater and as far as I know — there aren't any possibilities of alternatives," she said.

"If there's no way for people to recreate, that's also going to impact on the Gold Coast economy," she said.

Lois Levy, founding member Gold Coast environment group, Gecko, says much of the recreational areas will be impacted. ( ABC News: Dea Clark )

Development sites are at a premium and developers are eyeing off floodplains.

At a 25-hectare site known as The Cow Paddock at Carrara, a Gold Coast suburb several kilometres inland, a 2013 development approval stipulated that it have lifeboats on standby.

More than 500,000 people call the Gold Coast home and the population is forecast to grow to 850,000 in the next 20 years.

Lifeboats on standby was a development approval for this Carrara site. ( ABC News: Dea Clark )

Costly litigation risk

Environmental lawyer Justine Bell-James said local governments faced a dilemma when deciding on a course of action.

"Irrespective of what decision governments make on development, they could end up in court," Associate Professor Bell-James said.

She said saying no to a development in the short term could end up in a costly court challenge.

But Professor Bell-James said where she and other lawyers saw the litigation risk in the future was "against local governments for approving developments in hazard areas".

The Gold Coast City Council is already incorporating an 80 centimetre sea level rise into its mapping as part of the City Plan.

The council declined the ABC's request for an interview, but in a written statement pointed to a number of measures already undertaken to address issues associated with sea level rise.

That includes the installation of an artificial reef off one of the most vulnerable areas: Palm Beach.

The artificial reef is constructed from large rock boulders and sits 270 metres offshore. ( ABC News: Dea Clark )

It will work to prevent erosion by influencing waves and currents to preserve the sand.

Griffith University's Joerg Baumeister, who was working with the council on adaption strategies, said it was important to act now.

"We have to start to think strategically, and that costs money, but the earlier we start to prepare ourselves the better it is," Professor Baumeister said.

He said the Netherlands was a "wonderful" case study for the idea that cities could flourish despite rising sea levels.

"They are building new floating settlements for example … and even floating farms," he said.

Dr Harris agreed early action was essential.

This unit block on the sand dunes at Palm Beach is extremely vulnerable to sea level rise. ( ABC News: Dea Clark )

"The last thing we'd ever want is … [to] start losing these national icons, these really beautiful parts of the world that make Australia kind of famous but [are] also important to our culture."

But Gecko spokeswoman Lois Levy said unless more action was taken on reducing global warming, adaption would be pointless.

"The temperatures will be so high that basically it'll be a planet you can't live on," she said.

"We need definite targets on reducing greenhouse gases."

While authorities grapple with the problem … residents like Mr Green are left wondering what they can do.

"It's not just as easy to pack up and go. If we've got to leave here … how do you sell your house," he said.

Scientists say it is a tomorrow problem that must be tackled today.