We've been hearing it for years: The United Kingdom's nascent wine industry is poised to be a big winner from climate change. Vineyard plantings are booming! Quality is on the rise! Champagne producers are eyeing or buying vineyard land across the Channel to hedge their bets!
But a new study from the University of East Anglia finds that winegrowing there still has its perils, especially as U.K. growers have increasingly turned to Chardonnay and Pinot Noir for sparkling-wine production over cold-hardy varieties such as Müller-Thurgau and Seyval Blanc that they previously favored. Frosts, rainstorms and stereotypically English, cold, damp weather continue to play an important role year to year. That means wineries should expect smaller yields, which have a big impact on their bottom line.
The research, published today in the Australian Journal of Grape and Wine Production, is the first to take a detailed look at climate and weather patterns in the U.K.'s main winegrowing areas and evaluate the related risks and opportunities for wineries.
"We're hearing more and more about what's happening at the hot end of the spectrum of viticultural regions—those potentially at maximum suitability now," said lead author Alistair Nesbitt, a climate researcher at the university's School of Environmental Sciences. "Here in England, we're at the other end of the scale, so I really wanted to find out where climate change was either beneficial or not quite so rosy."
From 2004 to 2013, vineyard land in the United Kingdom increased by 148 percent, totaling just over 4,650 acres. That may not sound like a lot, but it's more acres than in the Australian state of Tasmania, another burgeoning cool-climate region, as of 2013. Established English sparkling-wine producers such as Nyetimber have been joined by 21st-century arrivals such as Gusbourne, Coates & Seely and the new Champagne Taittinger joint venture Domaine Evremond.
Much of that growth has been attributed to climate change making formerly marginal sites more suitable, particularly in counties such as Kent, Surrey, Sussex, Berkshire, Hampshire, Wiltshire and the Isle of Wight. The U.K. has been warming at a faster rate than the global average.
But is temperature alone the crucial factor for the U.K.'s future success? And are the climate-change models correctly predicting England's viability as a wine region? "I really wanted to test some of the assumptions being thrown out there," said Nesbitt, who previously worked in wine production. "If I were investing in a sector where I'm planting for 30 years out, I'd want to know more about what the threats and opportunities are."
After surveying U.K. wine producers about the role of climate change in the local industry, Nesbitt and four team members analyzed 60 years of climate and weather data and calculated the growing season average temperature in the main grape-growing regions. In southern England, since 1993, that temperature has consistently been pushed above 13 degrees C (55 degrees F), considered the minimum needed for successful cool-climate viticulture. Since 2000, in eight vintages, the growing season average temperature has been at least 14 degrees Celsius (57 degrees F), comparable to the Champagne region from 1961 to 1990.
The researchers then looked at the relationships between vineyard yields and temperature, rainfall and extreme weather events. They found that rising temperatures mask the familiar risks of short-term weather variations—such as cold snaps or storms at key stages of vine development—that can boost or slash grape yields from vintage to vintage.
The results echoed some details from a recent Harvard-NASA study that found that rising temperatures had bumped up harvest dates in France by 10 days, but dry weather was no longer required to achieve an early harvest. The growing season is becoming hotter and wetter.
The UEA study found that April and May had become warmer over the past 25 years, pushing up the typical dates for budbreak and shoot growth. However, the frequency of frosts during those months had not changed, leaving the developing vines vulnerable to higher levels of damage.
Likewise, flowering in southern England now typically occurs in June instead of July, but the volume of June rains had not changed, with wet weather increasing the risk of poor fruit set. An increase in October rains, meanwhile, raised the threat of mildew and rot during harvest.
Ultimately, the study found, crop yields were influenced most by the variability of rains in June, rather than by temperature.
While Nesbitt said the data won't surprise those already working in the U.K. wine business, it should help those planning to invest. With U.K. grape yields at only about 1.5 tons per acre, compared to more than 7 tons per acre in Champagne, a smaller-than-normal crop can put a winery in the red.
"People need to be aware that not every year is going be a bumper year and, when yields are low, they are really low," said Nesbitt, who is now working on a vineyard suitability map highlighting areas with less weather variability.
For wine drinkers, he said, the findings, combined with quality improvements in English bubbly, show reason for excitement about U.K. wine. "If we can identify where conditions aren't so variable and where producers can develop business plans to cope with weather events that impact yields, the future is bright."