NZ storms harbingers of climate change

The storms, droughts and floods that hit New Zealand last year could be a harbinger of climate change, weather scientists say.

New Zealand's weather extremes in 2008, from droughts in January to storms in July and August, are detailed in asummary published yesterday by the National Institute of Water and Atmospheric Research (Niwa).

The July and August storms that wreaked havoc across New Zealand caused $68 million damage and killed five people, Niwa said.

The drought in the west of the North Island early last year cost $1 billion, it said.

Niwa principal scientist James Renwick said the extremes could be a preview of how global climate change would affect New Zealand weather.

"I am not saying 2008 was a result of climate change, but we should expect to see more years like that," he said.

"The idea of a sunny year, but with some pretty violent storms, is consistent with climate change.

"We should expect to see more of those rainfall extremes."

Renwick said the extreme weather expected to be sparked by global climate change would affect New Zealand agriculture.

"It is really quite a challenge for agriculture. The good conditions you need to grow certain crops and raise stock will move around the country," he said.

"There will have to be some thought about where the different activities take place. For example, kiwifruit were first grown in the Bay of Plenty, then Hawke's Bay.

"They will probably be quite viable in the South Island in the near future."

The South Island had some of the most dramatic weather of 2008. Christchurch was the sunniest of the five main centres, with 2230 hours of sunshine compared with 2205 in Wellington, 2108 in Auckland, 2057 in Hamilton and 1912 in Dunedin.

Christchurch was also the driest of the five centres, with just 704 millimetres of rain compared with the 1662mm that made Wellington the wettest.

Canterbury recorded the highest temperature of the year with 34.8 degrees celsius at Timaru Airport on January 12 and March 19.

The sunshine and arid conditions were occasionally broken by violent rainstorms in the South Island. Marlborough, Canterbury and eastern Otago had more than three times the normal rainfall in July.

Marlborough also suffered in August, receiving more than four times the normal rainfall.

Weather extremes:

Coldest temperature minus 9.5C at Mount Cook on August 20.

Highest temperature 34.8C at Timaru Airport on January 12.

Lowest rainfall Alexandra with 376mm for the year.

Highest rainfall catchment Cropp River, in the Hokitika River catchment, had 10,940mm of rainfall for the year.

Heaviest snowfall Arthur's Pass closed three days after 1 metre fell, August 15-17.

- © Fairfax NZ News