A report which suggested sea levels would rise by 1m and affect 18,000 Christchurch homes has been backed up by a peer review.
Homeowners of the houses deemed vulnerable in the initial report were given a reprieve at the end of last year when Christchurch City Council put new planning rules on hold pending a peer review of the science used to make the decision.
A draft of that peer review is now back, and backed up the original report's modelling which relied on the International Panel on Climate Change (IPCC) and predicted 1m of sea level rise over the next 100 years.
View the draft findings of the peer review here.
Christchurch Coastal Residents United spokesperson Warwick Schaffer doesn't accept this.
"It is the extreme IPCC projection. What we're really supposed to be using as we understand is 'what's likely'.
"Is this likely? We would say this is not."
The group was set up to oppose changes to planning rules limiting future development in areas vulnerable to sea level rise.
Mr Schaffer, whose home is one of the 18,000 placed in the vulnerable category, said there was a lot at stake for people like him.
"A house is most peoples' single biggest asset so there's that but there's also the community. If you can't invest [and] can't build, these communities will start to get run down.
"So we've got to really make sure that what we're doing now is right."
The peer review found the original report presented misleading projections on the impact of sea level rise on coastal erosion, and concluded its impact would be felt by fewer households than the 6000 originally identified.
Tonkin and Taylor's Richard Reinen-Hamill helped draft the original report and maintains his team did a good job in the 20 days it was given by the council to draw up its report.
"We think that they've got a balanced assessment on the outcome. We think that those modifications will be positive in terms of improvements to what we've done."
Councillor Glenn Livingstone said while some people may not be happy with the review's findings, they could not deny the community was given a fair hearing, including a say on which experts should carry it out.
"They actually got to call the shots over how we were going to do it and a greater period of time was taken over it. So it wasn't a rushed out process and people are left in shock and awe over everything.
"So hopefully it was more respectful."
The facts around climate change were hard to deny, he said.
"I'm not sure what else we can do unless you pretty much go into climate change denial mode and say 'no it's not going to happen'.
"The sea's not suddenly going to stop rising at North Beach and then resume again past South Shore and most people know that."
The draft peer review is now open for feedback and the final version will be voted on by the full council at the end of August.