Winepress - July 2024

We need to talk about climate change

We’re already seeing the effects of warmer temperatures so what happens next?

CATHIE BELL

CLIMATE SCIENTIST Jim Salinger, who was 2024 KiwiBank New Zealander of the Year, says he is shocked at the lack of discussion around the effects of climate change on vineyard health and wine quality.

He told participants at WinePRO that temperature data from the 1960s to 2020 showed that Blenheim had become 1.5C degrees warmer over that time. This was affecting the timing of key viticulture milestones – he says budburst is about eight days earlier, veraison 14 days earlier, and fruit ripening to 20 brix was about 16 days earlier. “The first part of the season is telescoping in. It’s not so much in the rest of the season, but we are seeing significant change in the viticultural environment.” This means it could be “goodbye Sauvignon Blanc, hello Merlot” for Marlborough as increased temperatures due to climate change move growing zones down the country, Jim says. “Climate change will present huge challenges to viticulture in the future, and the primary threats are increasing drought, pests and diseases.” However, he is optimistic that these can be managed through irrigation, crop management techniques and new varieties. By 2090, temperatures are predicted to be up to 3C wamer. “You’re not talking Sauvignon Blanc in Marlborough at all. You’re going to make a warm wine style.” The country’s long thin geography is a good thing because it gives us options, Jim says. “The big advantage for New Zealand is that we have a wide latitude range and we can use it... We’re totally free to try new varieties in

regions. There is a lot you can do with pruning and crop management to adapt and ultilise those new opportunities.”

Diversifying the vines in each vineyard could also help, enabling growers to hedge their bets so that when one variety doesn’t perform, others can make up for it. Vineyard practices could include reducing canopy size and planting varieties that need less irrigation and have tighter stomata control. There is different management of the root stock to encourage it to spread out, such as decreasing vine density so the roots go bigger, and the vines can better seek out water. “Choose high vigour, drought resilient root stock. It might be time for a better root stock than 3309.”

Some viticulturalists are more relaxed about climate change because they say Sauvignon Blanc vines tend to be more forgiving than other varieties. Jim says that while “goodbye Sauvignon Blanc, hello Merlot” is a bit of a cheeky quip, there needs to be more discussion in the industry about climate change. “The temperatures are warming. It’s just a question of where and how much.”