Stock-picking wisdom could save a quarter of the world’s vineyards
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INTERNATIONAL - Wine and agriculture researchers studying the effects of climate change in vineyards have come to the same conclusion as decades of investors: diversify.
Scientists from some of the premier academic institutions in Europe and the U.S. found that diversifying grape varieties could reduce the losses to wine-growing regions by half should global average temperatures rise by 2 degrees Celsius. For years crop diversification has been part of the received wisdom on agriculture and climate change, but the authors of the study, published on Monday in the Proceedings of the National Academy of Sciences, argue theirs is one of the first to quantify just how much it can help.
The agriculture sector is among the most affected by climate change, with farmers across the world suffering the impacts of unusual temperature patterns and more extreme weather events, including floods and drought. But unlike say, corn, which has relatively few distinct subspecies, there are more than 1,000 varietals of wine grapes, which made it the perfect test case for a rigorous study of climate’s effect on crops. The study’s authors analyzed 11 of these, which together make up 35% of the total global area planted with vines.
Wine-making is specially vulnerable to global warming because even mild changes in temperature, humidity or soil conditions have an effect on the taste of wine. The research speaks not just to economic efficiency in changing conditions, but to questions about how growers will preserve their own individual and cultural identities as time moves forward, said co-author Ben Cook, a research scientist at Columbia University.
“If climate change does mean disaster for wine,” people aren’t going to shrug their shoulders and switch to beer, Cook said. “It means, in a lot of cases, a fundamental change to cultures and ways of living that have been established for a very long time.”
Vintners in California, Chile, France and Spain are already changing their growing methods, testing new techniques and varieties. Others have abandoned traditional farming areas and moved to cooler places, but that’s not a long-term solution, the paper said.
“As expansion of agriculture is one of the primary drivers of biodiversity loss,” the researchers said, “keeping agricultural regions in place and thereby preventing natural lands from being lost to new agricultural regions is a major international conservation goal.”
The team used records from vintners — particularly the budding and ripening rates they recorded for various grape types — to create simulated vineyards around the world and assessed how they would perform under three hypothetical temperature scenarios: 2-degree warming, 4-degree warming, and no warming.
The simulations suggest “turnover,” or variety-swapping, would result in 24% of wine-making areas lost to 2 degrees of warming, compared to 56% of areas lost without diversification. Early-ripening varieties such as Pinot noir and Chasselas, for instance, did well in new wine regions further north on the Northern Hemisphere, where wineries are moving as the weather warms. Grenache and Monastrell, which are later-ripening varieties, will become critical to maintaining current growing areas.
The benefits decline as the mercury rises. “Losses at 4°C are predicted to be particularly high in countries that are already warm; this includes losses reaching ~90% in Spain and Italy,” the authors wrote.
While the researchers ran their models on the Northern Hemisphere only, Southern Hemisphere wine makers are also experiencing the effects of climate change. Top Chilean winery Concha y Toro SA noticed that warmer and drier weather was impacting the quality of its vintages about a decade ago and in 2014 it invested $5 million to set up a research and innovation center.
“Adapting doesn’t mean that what we do is not viable anymore,” said Valentina Lira, Concha y Toro sustainability manager.
Diversifying grapes is just one approach to helping vineyards cope with changing conditions, according to Cook. Developing drought-resistant grapes is another. They may all help, even if there’s no total fix, he said. “We likely can’t completely adapt our way out of the problem.”