National Party MP Stuart Smith has described a Government climate change plan as the "science of bull****" during a talk in Ashburton this week.
The Kaikōura MP floated suggestions that warmer temperatures would not cause an increase in extreme rains - contrary to the Government's National Climate Change Risk Assessment (NCCRA) plan.
Smith, who is National's climate change spokesman, confirmed during the meeting that he was making official parliamentary inquiries with Climate Change Minister James Shaw around the legitimacy of the report, sparking several heated reactions from patrons.
Smith said, in light of recent floods in Mid Canterbury, that a Niwa study showed flooding risk would actually fall as the climate got warmer but had been ignored by the NCCRA document.
A recent Tailrisks Economics report into the NCCRA claims the Ministry of Environment-commissioned report was based on a false premise that climate change would increase extreme weather and flooding.
It then suggested that Niwa covered up flood risk results from a 2019 river and rainfall report.
"Claims that buildings and people will be generally subject to large increases in flooding risk are misleading.
"The Niwa data is not very informative because all it does is identify people and assets on historical floodplains.
"It does not take account of flood protection measures or make any assessment of the probability of flooding."
Smith said that the NCCRA report had been based on a pre-determined position.
"That's appalling," he said.
He added that many local councils would be misled because they only referred to the NCCRA when considering flood risk.
Niwadeclined to comment on Smith's remarks but chief scientist for climate, atmosphere and hazards Dr Andrew Tait said an increase of extreme rainfall was expected.
Potential changes to New Zealand's flood exposure were not covered in the 2019 Niwa report as a national climate change flood exposure study had not been done at the time, he said.