Climate change is tipped to alter Hawke's Bay's world famous wines - for the better - as more grapes ripen sooner on the vines each summer.

New Zealand's climate is changing with long-term trends towards higher temperatures, more hot extremes, fewer cold extremes, and shifting rainfall patterns in some regions, according to the New Zealand Climate Change Centre.

National Institute of Water and Atmospheric Research (NIWA) data shows New Zealand's average annual temperature has already increased by about 0.9C over the past 100 years.

Hawke's Bay is particularly significant as one of New Zealand's key horticultural and viticulture regions, according to the Ministry of Business, Innovation and Employment's (MBIE's) Regional Economic Activity Report 2015. The horticulture and viticulture industry accounted for 6.7 per cent of the region's employment last year, compared with 1.4 per cent for the rest of the country.


Lincoln University senior lecturer in viticulture Dr Glen Creasy said the changing climate could influence harvest times and wine styles.

"In Australia, they've done actual research on this and it's very definitely been advancing harvest dates in Australia so there's no reason to think it would be any different in New Zealand."

Increasing summer temperatures would mean a warmer growing season for grapes.

"It'll change the composition of the fruit so the flavours and the kinds of wines that can be made from the fruit will shift over time and so they'll probably have to change the way they manage the vines in order to keep the wine style that they want to produce the same.

"That's something that's already being done but it's a matter of being proactive rather than reactive."

Some wine styles were dependent on cooler weather and temperature increases might mean particular wine styles couldn't be made over the next 50 to 100 years, he said.

The warmer summer temperatures might also mean people could produce wine styles they couldn't reliably make now.

"If the managers are on top of things then it should mean, within a certain range anyway, that it will overall improve the quality or quantity of the fruit and the harvest."

Dr Creasy said less frequent but more severe frosts could also be a big concern for the industry.

"If you have frosts occurring that you cannot control and they occur too many times then it just doesn't become viable for the business to operate that way, so that may see some people shifting around a little bit as those frost events come in and people find out how bad they are.

"The one thing that's for sure, well at least in my opinion, is the risks associated with producing grape vines and grapes for wine are going to increase and so management will have to adjust to that."

The MBIE report showed 5966 were employed in the Hawke's Bay horticulture industry last year, 2639 in grain, sheep and beef cattle farming and 4006 in other agricultural industries.

Plant & Food Research science group leader, systems modelling, Brent Clothier, said growers and farmers were good at planning ahead regardless of whether they were consciously adapting to climate change. They made changes as part of everyday management.

Dr Clothier said different cultivars of crops might be necessary as the climate changed and different crops might be grown in different places.

Tropical crops, such as those grown in Queensland, might take the place of kiwifruit in Northland, where they struggled to grow without Hi-cane to stimulate flowering. A loss of very cold temperatures might allow more horticulture in Central Hawke's Bay.

He said climate change was incremental so it was hard to tell what crop changes had been a result of climate change and what had been driven by ingenuity and risk taking.

According to MBIE, 501 Hawke's Bay people were employed in forestry last year.

Scion Research principal scientist Dr Tim Payn said more storms leading to increased risk of erosion was front of mind for those in the forestry sector.

"So probably not so much the temperature as the mixture of temperature, rainfall and those sort of extreme events."

A loss of top soil through erosion scars could decrease forest productivity. Fire prevention and monitoring was another priority.

Dr Payn said the forestry sector was looking at climate issues all the time and incrementally adapted as things changed. Ongoing management included disease programmes, weed control, fire risk and wind risk.

Trinity Hill chief executive Michael Henley said increasing temperatures were beneficial to the company as it grew red varieties which revelled in warmer weather.

"There's only ... two wine regions in New Zealand, ourselves and Waiheke Island that focus on the more fuller bodied red wine and they can do with warmer weather."

Mr Henley said Trinity Hill had had consistent vintages over the past four years and hoped for more of the same over the coming years.

"We're hoping that the conditions stay warm and dry, and at the same time we're hoping that in a perfect scenario we get rain at the right times when the vines need it."

Mr Henley, who is also Hawke's Bay Winegrowers chairman, said the region had a moderately cool climate for grape growing and warmer temperatures were good for grape growing.