What will global warming do to the wine industry?

Grapes like these can't handle the heat. See more wine pictures.
iStockphoto.com/YinYang

Buy up those bottles of red Bordeaux, Mosel Riesling, Rioja, Chianti and Barossa Shiraz while you still can. No, it's not a rerun of Prohibition -- it's global warming.

While the wine industry isn't a major contributor to greenhouse gas emissions (around 0.1 percent of global carbon emissions), it could be a casualty of climate change within the next 50 years [source: Atkin]. Wine grapes are delicate and grow in a narrow band around the world. The cumulative effects of greenhouse gases in Earth's atmosphere are causing a change in climate pattern. In the last 100 years, the average global temperature has increased by about 1.4 degrees F (0.7 degrees C) and is predicted to rise an average of 2 to 11.5 degrees F (1.1 to 6.4 degrees C) by the end of this century [source: EPA and EPA]. This temperature rise and the extreme weather patterns that will accompany climate change threaten this band of wine-producing regions worldwide.

In classic (French) winegrowing tradition, there are four ingredients that come together to produce great wine: the weather, the soil, the topography and the variety of grape. This is called the terroir, and it gives each wine a flavor specific to where the grapes were grown. For example, a Merlot grown in Bordeaux won't taste the same as a Merlot grown in Napa Valley because the terroir is different. Three of those four factors have always been thought of as safe from human influence: the slope of the vineyard, the soil and the climate. At least until now.

Wine grapes are generally grown in places where frost is rare, temperatures are moderate (on average, between 50 and 68 degrees F, or 10 and 20 degrees C) and there's just the right touch of rain and humidity. Any hotter and you're in the raisin industry.

Grape Growing: Climate Is Crucial

Vineyards may soon be relocating to places like Finland and Ireland.
Vineyards may soon be relocating to places like Finland and Ireland.
iStockphoto.com/THEPALMER

Through the process of photosynthesis, plants use sunlight, carbon dioxide (CO2 ) and water to make sugar. When temperatures and levels of CO2 increase, grapes ripen more quickly resulting in fruit with higher concentrations of sugars, lower acidity and higher pH levels. What the wine industry is facing is not only a change in temperature but a change to the very ingredients of the terroir. Resulting wines end up being less delicate with higher alcohol content.

A recent paper published in "The Proceedings of the National Academy of Sciences" found that if climate change patterns play out as expected (with hotter temperatures, extreme heat waves and droughts), viable grape-growing regions will shrink worldwide by nearly 80 percent by 2100 [source: Weise].

Growing seasons have already changed: Over the last 50 years, seasonal temperatures have increased by an average of 3.6 degrees F (2 degrees C) in Spain, a high-quality wine-producing region [source: Wood]. France, too, has seen the effects of climate change. Between 1945 and 1999, temperatures rose enough to move harvests forward by three weeks to a month across many French vineyards [source: COSMOS].

In the United States, climate change threatens grapes in Napa, Sonoma and Santa Barbara counties. Over the past 75 years in Napa, for instance, temperatures have risen nearly 5 degrees F (3 degrees C) while the growing season has increased by more than 50 days [source: Weise]. By 2050 it's predicted that large areas of southern Italy, the Iberian Peninsula, Australia, California, South Africa and southern France will no longer be able to support the growth of wine grapes because of the hotter weather.

While it may be the death knell for your favorite wine, the effects of climate change are also opening up new countries to the wine business. Regions with perfect winegrowing conditions are shifting, and vineyards are beginning to pop up in southern England, Denmark, Sweden and Finland. One United Nations model predicts the geography of wine growing could shift on average 111 miles (180 kilometers) to the north of where we currently know it to be [source: COSMOS].

In the meantime, and before we're able to break open a bottle of Irish pinot noir, winegrowers are trying methods of mitigating the effects of global warming on their crops. Some are buying up high-altitude properties where temperatures are cooler, reducing sun exposure by planting vineyards on north-facing slopes (south-facing in the Southern Hemisphere) and harvesting earlier.

Related HowStuffWorks Articles

More Great Links

Sources

  • Aparicio, Marcelo. "Global warming threatens to redraw world's wine map: experts." StopGlobalWarming.org. 2008. http://www.stopglobalwarming.org/sgw_read.asp?id=954252182008
  • Atkin, Tim. "Red alert." The Guardian. 2008. http://www.guardian.co.uk/lifeandstyle/2008/mar/23/foodanddrink.shopping1
  • "Basic Information - Climate Change." U.S. Environmental Protection Agency. 2009. http://www.epa.gov/climatechange/basicinfo.html
  • "French wine about global warming." COSMOS magazine. http://www.cosmosmagazine.com/news/767/french-wine-about-global-warming
  • "Future Temperature Changes." U.S. Environmental Protection Agency. 2007. http://www.epa.gov/climatechange/science/futuretc.html
  • "Global warming will hurt Californian wine industry." NewScientist. 2006. http://www.newscientist.com/article/mg19125604.700-global-warming-will-hurt-californian-wine-industry.html
  • Joseph, Robert. "Tippling point." The Guardian. 2008. http://www.guardian.co.uk/lifeandstyle/2008/mar/04/foodanddrink. climatechange
  • Kay, Jane. "Now's the time to cellar wine." San Francisco Chronicle. 2006. http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2006/07/11/MNG03JT3EV1.DTL
  • Penland, Jack. "Wine and Global Warming." ScienCentral. http://www.sciencentral.com/articles/view.php3?article_id=218392849& cat=2_6
  • Root, Jessica. "Bask In The Warm Glow Of Wine, Without Warming The Globe." Planet Green. 2008. http://planetgreen.discovery.com/food-health/climate-change-wine-nature-conservancy-new-york.html
  • Sandell, Clayton. "Global Warming May Sour Wine Sales." ABC News. 2006. http://abcnews.go.com/Technology/GlobalWarming/Story?id=2173340&page=1
  • Weise, Elizabeth. "Wine regions feel the heat." USA Today. 2006. http://www.usatoday.com/weather/climate/2006-06-01-wine-warming_x.htm
  • Wood, Danny. "Spanish wine makers fight climate change." BBC News. 2008. http://news.bbc.co.uk/2/hi/europe/7547610.stm