It's a stark reality to face for homeowners. As areas approach 30cm of sea-level rise, the one-in-100-year storm will become an annual event.

"They'll be asking questions like, 'who's going to protect us? Who's going to pay?'" said climate scientist Professor Timothy Naish.

"That of course starts conversations around insurance, mortgages."

But will homes affected by sea-level rise even be covered?

Head of the Insurance Council Tim Grafton said standard house policies do provide cover for sudden and unexpected events like fire, earthquakes, tsunamis and even storms.

But the sea-level rise on its own is not covered because it is not sudden and it is not unforeseen.

Insurance companies are also starting to track storms and coastal flooding caused by rising sea levels.

"Events are happening more regularly, they're more severe and they're costing more to return back to where we were when we started," said IAG CEO Amanda Whiting.

Whiting gives the example of Westport which saw two one-in-100-year storms in a single year. The flooding in July alone saw an insurance cost of $80 million.

"If you look at the floods in Tairawhiti and Gisborne that we've had, you've had two one-in-a-hundred-year events in a single month - that's a very short 100 years," said Green Party co-leader James Shaw.

As these weather events become more frequent premiums and excesses will increase too.

"And over time if the risk is so high - insurance can't accept it," Grafton warned.

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Many coastal homes will virtually become uninsurable. Tracking the vertical land movement, the scientists found if nothing is done to reduce carbon emissions, key pieces of infrastructure are at risk with regular coastal flooding 10-15 years earlier than expected.

"It could cause flooding of Auckland motorways like the North-Western to occur once every year instead of once every 100 years," said NIWA hazard analyst Ryan Paulik.

In Christchurch, South Brighton is sinking and up the coast in Kaiapoi it's doing it at a rate that will double its annual sea-level rise.

In Nelson, the Richmond coastline is sinking four millimetres a year and the nearby airport is at risk.

There are similar issues along the east coast of the North Island too. As we fly into Napier's newly-upgraded airport, it's obvious just how vulnerable it is.

Napier Airport is built on marshland, soft sediment and on a tectonic plate that's moving. The data shows the land sinking by around 4mm a year. While 30cm of sea-level rise was predicted for around 2065, now it's expected to happen in the next 18 years.

So for those in charge of safeguarding these areas there's a new timeline.

"It probably raises some flags to say 'okay we might have to deal with this earlier than we thought'," said Hawke's Bay Regional Council principal engineer Jose Beya.

So what are the solutions?

"The first one is let's not build in those places that we know are high risk," said Whiting.

"The second one is how do we mitigate the risk by building infrastructure... and the last one is retreat and I know that's not a particularly popular one but in some cases we will need to move homes to higher land or a different land package."

And Whiting said those options need to be discussed now - not later.

We've already seen creative solutions in New Zealand. After the Christchurch earthquakes some residents in Flockton Basin sold their homes to the local council.

Flood mitigation options were put in place and now the homes in the area are future-proofed against the elements.

Conservation Minister James Shaw said we're likely to see communities get litigious.

"Various groups are going to start taking - whether it's local authorities or central government or businesses or others - to court to say 'hey you need to be taking account of these decisions because you've got a duty of care for over these communities'," he warned.

The scientists hope the data will fast-track plans to mitigate climate change.

"To be forewarned is to be forearmed so the science gives us warning and there's still time," Prof Naish said.

But only if we make use of it.