Climate change could affect Marlborough's grape flavours
Marlboroughs sauvignon blanc could one day lose its famed zing if temperatures both above and below ground keep getting warmer. However, winemakers are a clever bunch so dont expect to taste too much of a difference anytime soon. Bragato Research Institute viticultural extension and research manager Len Ibbotson said the wine industry had already started adapting to warmer seasons. Theres a certain amount that we can do from a viticulture and winemaking perspective to buffer those changes, Ibbotson said. READ MORE: * Mackenzie region forecast to feel climate change heat * Frosty starts as Marlborough's winter winds back the years * Blenheim records overnight temperature 10C above average Weve had a run of really warm seasons in Marlborough, much warmer than the long term average, and we havent seen a dramatic shift in wine style. Ibbotson said these tools included harvesting earlier, or blending with subregions planted in cooler climates. That works for now, will it work in 20 years or 30 years? Thats all going to depend on how severe those changes might be, he said. Over time that might require that we take a different approach to how we grow. The Marlborough District Council commissioned Niwa to research projections and potential impacts of climate change for the region, with the findings released last month. Niwas report projected average maximum temperatures to increase up to 3 degrees Celsius by 2090. The average number of hot days (over 25C) was expected to increase, with up to 65 more by 2090. Frosts were expected to decrease, and there could be more extreme, rare rainfall events. As a result, changes to Marlboroughs (diurnal) temperature range may alter the characteristics of the grapes grown in the region, the report said. Ibbotson said fewer frosts would be a positive for the industry, but there were also some challenges like increased drought, which meant less water available for the region. The drought conditions can be really challenging, particularly if theyre linked to low flows in the river, generally speaking less rainfall is good for grapes, it means less disease pressure, and I think the modelling Niwa are suggesting is a slight increase in winter rainfall and a slight decrease in summer rainfall, thats a positive story. Grapes, compared to a lot of other crops are a fairly efficient user of water, we dont use a lot. But there are definitely some risks and uncertainty around water availability. Nelson Marlborough Institute of Technology viticulture tutor Dr Stewart Field recently won an award from the American Society for Enology and Viticulture for his grapevine soil research alongside co-authors from Charles Sturt University in Australia and Trent University in Canada. The research was conducted to understand how soil temperatures affected grapevine growth a subject linked to climate change. The research concluded soil temperature significantly affected grapevine growth, as colder temperatures took carbohydrates into their roots like storage. Under cool conditions it stores them in the roots, simulating a bad environment, maybe it wants to store reserves for future survival, Field said. When theyre warm they tend to put them up into the shoots and grow shoots. So the soil temperature definitely is lowering the amount of flowers that turn into fruits. With warmer soil you get more shoot growth and better fruit. Field thought more research would need to be undertaken in order to better understand how climate change would affect the industry. I think the temperature definitely will have an affect, he said. Probably the loss of the green flavours, on warmer years were losing those. Unless theres some vineyard management techniques that you can use to combat that. The full NIWA climate change report could be found on the Marlborough District Council website .