More extreme weather for Central Otago in 2099 forecast

A climate change report predicted Central Otago summers would be longer and warmer. Photo / File

A report on the effects of climate change in Central Otago was not ''the oracle for climate change'' in the region but would be a valuable tool for future planning, the Central Otago District Council (CODC) has heard.

Councillors yesterday discussed the report, which the council commissioned from Bodeker Scientific, in Alexandra, to help with long-term planning.

The report predicted that by the end of the century, Central Otago would be warmer with more extremes - including flooding, wildfires and storms - and there would be far less snow cover on the mountains than at present.

Scientist Chris Cameron, of Bodeker Scientific, said last week those changes would cause flow-on issues for irrigation, horticulture and viticulture, and were likely to influence the number of people wanting to move to the region.

The report said district temperature were likely to rise by several degrees by the end of this century.

The annual total rainfall was not predicted to change much but the intensity of rainfall would increase and there would likely be more extreme rainfall events.

The changing profile of rainfall throughout the year, as well as less water being locked away as snow until spring, would mean less water available for irrigation and storage as well as knock-on effects for river flows (including minimum flows).

In addition, Mr Cameron said there were likely to be about 53 fewer frost days, about half that experienced now.

Summers would be longer and warmer, with up to 64 more summer days, about double the present number, depending on location.

Maximum temperatures would be up to 5.8degC warmer. Winters would be warmer by between 2degC and 4degC, compared with 2009 data, and some areas would have no spring or autumn frosts.

Councillors said yesterday the predictions would have implications for things such as water storage and stormwater drains, and wanted the report distributed more widely.

CODC staff said the report would go on the council's website for all to view and use. It would also go to the ORC.

Central Otago deputy mayor Neil Gillespie said the report was ''not the oracle for climate change in Central Otago'', but a tool for the council to use.

Councillors and staff agreed the report contained predictions only and it would be wrong to say ''that's what's going to happen''.

But it would assist the council in its long-term planning, and would possibly be updated every 10 years.

- additional reporting Y'vonne O'Hara