Thinking about what wine to serve at your holiday dinner? As this ScienCentral News video reports, it turns out that global warming has actually made it easier to buy a good wine.
Wine and Warming
It may be no surprise that temperatures in many wine-growing regions around the world have increased over the last 50 years, but what has that done to the quality of wine?
"We found that as the growing season climates got warmer, the vintage quality improved," says Greg Jones, an associate professor of geography at Southern Oregon University who studies climate and how it affects agriculture, in particular grapevines. Jones and his team found an average warming of 1.25 °C (2.3 °F) in the major grape growing regions throughout the world, and related that warming to vintage ratings, a subjective measure by which wines are compared from year to year.
But how does climate affect wine quality? "Typically what a grower and a wine maker are looking for is a balance between three things: sugar, acidity and flavor," explains Jones. "Sugar is very important, because it allows the must—the grape juice—to be fermented to an alcohol level that is very good for that wine style. Acidity is very important because it allows the wine to be very friendly with food. The flavors are the most important aspect, though, because flavors are different for different wine styles in different regions. What happens in a grape growing environment is that sugars typically come into ripeness first and flavors are what the wine maker waits for—to the optimum balance. The problem is that if you wait too long for flavors, then acidity balancing can fall out."
Grape growing, like a lot of agricultural industries, is very dependent upon individual weather events and long-term climate.
"Grapes are grown in very narrow climate regions, that can be categorized from cool to hot," Jones explains. "And what we found is that if you're in cool climate growing regions, you tended to benefit a little bit more from the warming, meaning that they were more able to ripen the fruit and produce better wines; while on the other end of the spectrum, in the warm to hot climates, the warming pushed them outside the realm of being able to produce a good balanced wine."
So wine has improved over the last 50 years, but what will happen in the future? Jones and his team used a computer model to project the future growing season climates, and found that temperatures will increase on average by another 2.0°C (3.6 °F) in those same wine regions. Based on that data, Jones says this may improve wine from cooler regions, but could bring challenges for wine-producers in others.
|image: Beringer Vineyards|
"If you're in a region warmed beyond your ability to produce the same wine style, then you need to think about how you're going to adapt to those changes, because mitigating climate is not necessarily an easy thing to do," says Jones. And because temperature increases are likely to continue, Jones says wine producers, particularly in warmer regions, should be prepared.
"Climate determines the broad wine style that a given region can produce. In the cooler climate regions we might see a much greater ability to produce balanced wines—flavor, sugar, and acidity ripe wines will be easier to achieve. In warmer regions, we might be much more challenged, because sugars will become ripe much earlier in the season while flavors may take the same amount of time to become in balance. Therefore, you may have these bold, higher alcoholic wines that don't have the flavor profiles that they have today."
Jones emphasizes that climate change is something that everyone should think about and be prepared for. He says, "All sectors of society need to be aware that climate change is an issue that's out there, that we need to understand the potential impacts. That's what scientists are trying to do—to try to model and mimic the Earth's atmosphere and its systems so that we can better project in the future the potential changes and impacts to society."
This research was presented at the November 2003 meeting of the Geological Society of America and is in review for publication in an upcoming issue of Climatic Change. The research was funded by Southern Oregon University with contributions from the Climate Impacts Link Project on behalf of the Hadley Centre and U.K. Meteorological Office, the Center for Climatic Research at the University of Delaware, and Tom Stevenson, author of New Sotheby's Wine Encyclopedia: A Comprehensive Reference Guide to the Wines of the World.