Central and local Government must start planning now for a potentially catastrophic sea level rise, opposition parties say.
They're reacting to a report by Parliamentary Commissioner for the Environment Jan Wright which warns thousands of homes may have to be abandoned and infrastructure worth billions could be lost.
The report says it's uncertain how much sea levels will rise, and how quickly, but it's happening.
"We're talking about people's homes, which are also their financial security," said Labour's climate change spokeswoman Megan Woods.
"The fact is that over 9000 New Zealand homes lie less than 50 centimetres above the spring high tide line."
The report says the Intergovernmental Panel on Climate change has projected that the sea level around New Zealand will rise about 30cm in the next 50 years, and continue to rise for centuries after that.
The Green Party's Eugenie Sage says Environment Minister Nick Smith has failed to provide local authorities with a clear national direction on how to plan for sea level rise.
"It needs to be treated as a priority issue," she said.
Prime Minister John Key's science advisor, Professor Sir Peter Gluckman, has welcomed the report.
"The commissioner is right in distinguishing the urgency of actions aimed at mitigating global greenhouse gas emissions," he said.
"This should allow for prudent and science-informed planning, not complacency."
Dr Smith says the report is "a useful contribution" to the debate around climate change.
"Sea level rise is increasingly becoming a reality for the many New Zealanders who live along our extensive coastline," he said.
"The Government already has work underway in this area ... it is updating its guidance for councils on adapting to climate change."
Major of Dunedin, Dave Cull, says the Government needs to do more than just provide funding.
"This is a problem of such extent that no one agency would be able to cope with the responses required anyway, so it may be not a matter of money so much as legislative enablement to give us the tools, the mechanisms to deal with something on this scale," Mr Cull told the Paul Henry programme this morning.
Mr Cull says the city has been looking at various ways to plan for the rising levels.
"We've had a couple of engineering reports which talk about digging in big walls to block off incoming sea water, pumping the water out [but] we don’t actually know yet whether they're viable …we have been conscious of this so about a year ago we out in some rules whereby if you built a new house in this area or if you added to an existing one you had to build the floor level quite a bit higher than is currently the case."
He says Dunedin needs a "major community conversation about this".
"We have to talk about it to know what to do about it."
CITY ASSETS WITHIN 150CM OF SPRING HIGH TIDE MARK