Kaipara’s mayor has been criticised for an “irresponsible” climate change stance, after saying Cyclone Gabrielle was part of normal weather cycles and not made worse by climate change.
Kaipara mayor Craig Jepson said he would like to see the science that shows the cyclone was made worse by climate change.
Jepson’s stance comes despite climate scientists estimating man-made climate change increased the cyclone’s rainfall by 10%.
“In my view, weather’s cyclic and we’ve had these events before,” Jepson said.
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Cyclone Gabrielle produced 220mm-340mm of rain over Kaipara.
It caused hundreds of homes to be evacuated from Dargaville and Ruawai, cut power and left 13 homes either red or yellow stickered.
Council estimates it will cost $12m-$21m for road and infrastructure repairs, plus land drainage.
Jepson pointed to the 1938 Esk Valley floods and Cyclone Bola in 1988. He also compared flash flooding in Mangawhai on February 24 to localised flooding in Kerikeri in 1981, which saw 265mm of rain fall in three hours.
“These events keep repeating themselves. My belief is the science is not definitive.”
Jepson said he would also like to know how much the cyclone was intensified by last year’s Tongan eruption.
Crown research institute Niwa has said there was no established link between the events, but it is believed the eruption increased the Earth’s temperature.
A new international study will examine whether the eruption of a Tongan volcano in 2022 can be linked to extreme weather events experienced in New Zealand, including Cyclone Gabrielle.
Jepson did accept humans have had some affect on the climate, but thought the jury was out on just how great that impact was.
Jepson said some low-lying or riverfront homes in Kaipara may need to move due to flooding, but said they had always flooded.
However, Far North deputy mayor Kelly Stratford – who is chairperson of the Northland Civil Defence Emergency Management Group – criticised such climate change scepticism as irresponsible and short-sighted.
“He can believe that if he wants. But it is irresponsible leadership to not be able to see that flood mitigation that was in place previously was not able to withstand the amount of rain that Gabrielle delivered,” Stratford said.
“It is proactive to accept that the volume of rain and intensity of winds during these storms has been exacerbated by climate change and will continue, so we must mitigate and adapt – or there will be greater loss and burden.”
Jepson has already made waves in his first five months as mayor.
He was asked to resign after he banned karakia at council meetings and asked Kaipara’s first Māori ward councillor how Māori she is.
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Dr Sam Dean, a principal climate scientist at Niwa, said while cyclones are a normal part of the weather system, warmer seas caused by climate change fuel such storms and make them more intense.
Dean and other Kiwi scientists from different organisations will study Cyclone Gabrielle to model exactly what the impact of climate change was, while the World Weather Attribution is due to publish a rapid study specifically looking at rainfall in Tairāwhiti and Hawke’s Bay on Thursday.
But he estimated man-made climate change increased the rainfall by 10%, based on similar studies on New Zealand severe weather events over more than 10 years.
“It may be that 10% extra rain is the straw that breaks the camel’s back in terms of damage – it’s very specific to your location,” he said.
As well as climate change, Cyclone Gabrielle’s severity in New Zealand was increased by other factors including the La Niña weather pattern and a high to the east of the country holding the storm in place, Dean said.
An international study will also examine whether the Tongan volcanic eruption can be linked to extreme weather events experienced in New Zealand, including Cyclone Gabrielle.