Could global climate change put an end to the centuries-old French wine industry? Affects on the vineyards might not be catastrophic today, but a new study published in Nature Climate Change suggests climate change is definitely making its mark on how French wine is produced.
"The wine industry is so closely connected to what's happening with climate change," says the study's lead author Benjamin Cook, a climate scientist at Columbia University's Lamont-Doherty Earth Observatory and NASA's Goddard Institute for Space Studies. "We focused on France because they've been making wine for centuries and have records going back 400 years."
About that: To really understand the study, you have to understand a little bit about winemaking. So many things affect what make a stellar wine from the type of grape and the soil to the vineyard's microclimate and elevation. This is a concept referred to as the wine's terroir.
In France, this idea of terroirs eventually led to the Appellation d'Origine Controlee system in 1935 (it was replaced with Appellation d'Origine Protegee in 2012), a French certification system that defines geographical regions and regulates agricultural products like wine.
As you can imagine, the climate in each terroir varies greatly. In much of France, harvest records have shown that the best vintages have been those where the weather included lots of spring rain, a hot summer and a late-season drought, which forces the vines to fruit and mature fast.
Winemaking is one of the cornerstones of the French economy. In 2014, 1.22 billion gallons (4.6 billion liters) of wine was produced in France, up 12 percent over 2013. More than 10 million people visit the wine regions of France every year. So it's no surprise the French people consider winemaking a sacred part of their heritage.
In the study, Cook and his coauthor Elizabeth Wolkovich, an ecologist at Harvard University, analyzed climate data, reconstructions of temperature, precipitation and soil moisture, and vineyard records dating back to the 17th century. "What we found was vineyards were harvesting on average 10 days earlier," Cook says. "And higher quality wines are associated with earlier harvest dates in this region and this connection is still holding."
During the 20th century, France warmed about 2.7 degrees Fahrenheit (1.5 degrees Celsius), and continues to climb. Up until the 1980s, the climate in France was too cool to force an early harvest without the extra heat added by the late-season drought. That seems to have now changed. "Today, vineyards are achieving these early harvests without the late-season drought," Cook says. "It's not clear what this will mean in the long term, but it's a clear signal of climate change."
Cook says it's not all doom and gloom for the French wine industry, by far. In fact these temperature changes have actually been good for many of the French vineyards, but that might not hold true forever. "We found evidence that there may be an upper limit in how early grapes can be harvested," he says.
In 2003, when a record heat wave hit Western Europe and forced the earliest harvest ever in France, the wines produced should have been exceptional quality, but they weren't. "It's worth noting that years like 2003 are what we expect in the coming decades with climate change," he says.
Could we one day see French vineyards start irrigating their grapes? Absolutely. Might we one day see a Burgundy region sans pinot noir or a Bordeaux without cabernets? Possibly. A 2013 study projected that by 2050, two-thirds of today's wine regions might not have climates suitable for the grapes they grow now.
So could France be forced to start growing grape varieties that are adapted to hotter, drier conditions? "I'm not saying anyone should do these things specifically," Cook says. "What our study shows definitively is climate change is having an impact and it might make it very difficult to grow grapes in certain parts of certain regions."