Local climate experts and commentators have warned that Hawke's Bay is particularly vulnerable to flooding, given its proximity to the coast, and rivers. Photo / Paul Taylor
1411200120HBTPTcric.JPG Dr Kathleen Kozyniak: "We are more likely to have deluges as temperatures warm." Photo / Paul Taylor
Christian Fuller
One week on from the flood that stunned Napier and the long term forecast is for more deluges.
Local climate experts and commentators have warned that Hawke's Bay is particularlyvulnerable, given its proximity to the coast, and rivers.
Last Monday, more than 200mm of rain fell between 12pm and 8pm in what was a "one in 250 year' event. However, similar events are expected as temperatures increase.
Kathleen Kozyniak, Hawke's Bay Regional Council principal air scientist, said warmer temperatures equalled more risk of localised downpours.
"It's difficult to pin any single event on climate change though modelling can compare the likelihood of such an event happening now to when the world had lower CO2 concentrations.
"I can say that we are more likely to have deluges as temperatures warm.
"Hotter temperatures increase evaporation and in the right conditions, that evaporated moisture can condense and produce the sort of deluge we saw.
Kozyniak said it was "perilous" to ignore what science says is likely to happen as greenhouse gases increase.
"Particularly when trends are emerging in line with that science.
"The hotter we get, the shorter the return periods of extreme events become. The likelihood depends on whether the world can contain its greenhouse gas emissions.
"Like many parts of the country, flood events aren't the only worry.
"Hotter temperatures mean we'll move more quickly into drought between rain events and our coastline is at risk from sea level rise."
Kozyniak said Hawke's Bay was part of a global community, and reducing our carbon footprint contributed to the world's environmental health, however insignificant our own efforts may feel.
HBRC chairman Rex Graham said denying climate change was denying science.
"Extreme weather events will occur in NZ and we are especially vulnerable in Hawke's Bay.
"Everything we do at the HBRC has a climate change factor built into it to help make our region more resilient but it will never be enough without a proactive and collective community response."
After Monday's flooding, Napier mayor Kirsten Wise acknowledged there could be similar weather in the future, due to climate change, and said the council would look at its wastewater and stormwater treatment spending.
One week on, Hawke's Bay Today asked Napier City Council whether Monday's flood had prompted changes to the council's approach.
Acting CEO Keith Marshall said there would be focus on the worst hit areas on Monday.
"In the current drafting of our next Long Term Plan, council is looking at spending over $20 million on stormwater improvements over the next 10 years with a focus on upgrading the areas worst affected on Monday night."