Climate heat means new wine from familiar places

Each great wine is a unique product of place and climate. Rising heat could force new wine into old, prized bottles from famous cellars.

LONDON, 30 January, 2020 – As global average temperatures rise, so does uncertainty for the world’s wine-growers – with new wine the likely result. The great Bordeaux region of France will survive – but only if it stops serving claret.

Burgundy will still value its vines, but these won’t produce the high-priced tipple that the law defines as burgundy. Instead, what comes out of the cellars of Beaune or the Cote d’Or will be more like the output now from the southern Rhone.

That is always supposing that the growers keep up with rising temperatures by choosing grape varieties more likely to flourish with climate heating. A new study by European, Canadian and US scientists suggests that, even if the world’s most prized vineyards do abandon the grape varieties that made them prized in the first place, they will still lose up to a quarter of the space now in cultivation.

And if they don’t, the great wine regions of Europe could say goodbye to half their vineyards altogether. Producers in cool climates – Germany, New Zealand and the Pacific Northwest – could avoid major losses, but they will be tempted to switch to later-ripening varieties.

“Wine is like the canary in the coal mine for climate change impacts on agriculture, because these grapes are so climate-sensitive”

In the United Kingdom, where until very lately any wine harvest has been a gamble, the terrain might become suitable for at least five new varieties. New Zealand’s range of grape choices could double.

But Burgundian growers might have to forego the famously temperamental pinot noir grape and switch to grenache, or mourvedre, known in Spain as monastrell. The vintners of St Emilion, Pomerol and Medoc could see their cabernet sauvignon and merlot varieties replaced by mourvedre, according to research in the Proceedings of the National Academy of Sciences.

In fact, Europe’s growers have already had several warnings: hot and dry summers are now, for France, the norm. Extreme summer temperatures take their toll not just of the yield on the vine, but also of the people who have to pick the grapes, and even of the oak trees that provide the bark for the corks in the finished product.

Temperatures have already risen by more than 1°C worldwide, and the cool region of Champagne could be about to lose its sparkle.

Medieval records

But the new study is about far more than just the high-priced product of high-status wine regions. There are more than 1000 varieties of the grape Vitis vinifera, many of them sensitive to specific temperature and rainfall conditions. Even more helpfully, scientists can call upon harvest records that date back to medieval times.

So the grape seemed a good proxy for all of agriculture: from apples to wheat, from bananas to brassicas, the world’s growers can call on a huge range of crop varieties to buffer them from the shock of climate change driven by ever-increasing use of fossil fuels and ever-greater emissions of greenhouse gases into the atmosphere.

“In some ways, wine is like the canary in the coal mine for climate change impacts on agriculture, because these grapes are so climate-sensitive,” said co-author Benjamin Cook, of the Lamont Doherty Earth Observatory at Columbia University in the US.

The scientists considered 11 kinds of cultivar and dates of budding, flowering and harvest matched to seasonal temperature records, and found that if global temperatures rise by 2°C – and there is every indication that they could rise by more than 3°C – at least 51% of current wine-growing regions could be wiped out.

Higher warmth difficulties

“These estimates however ignore important changes that growers can make,” said Elizabeth Wolkovich, of the University of British Columbia, another author.

“We found that by switching to different varieties, vintners can lessen the damage to just 24% of areas lost. For example, in Burgundy, France, vintners can consider planting more heat-tolerant varieties such as syrah and grenache to replace the dominant pinot noir. And growers in regions such as Bordeaux may swap out cabernet sauvignon and merlot for mourvedre.”

But that’s if warming is limited to just 2°C. “At four degrees, around 77% of all areas may be lost, and planting new varieties will limit this to 58% losses,” said Ignacio Morales-Castilla, of the University of Acalá in Spain, who led the study.

“Wine-growing regions can adapt to a lower level of warming but at higher warming, it’s much harder.” – Climate News Network