Climate Change & Wine

KEY CONCEPTS

• Fine wine production is likely to shift due to climate change. Among agricultural products, wine grapes are one of the most sensitive crops to variations in temperature and precipitation. 

• In the United States, the average growing season temperature (April-October) has risen 2.0°F since 1970. 

• Premium wine grapes can only be grown in places that support a delicate balance of heat and precipitation. Globally, wine grapes are grown in areas where the average growing season temperature (spring through fall) occurs within a narrow range of 18°F. For some grapes, such as pinot noir, the average temperature range is a much narrower 3.6°F. 

• Other climate change threats to wine production include exposure to wildfire smoke, extreme heat waves, heavy precipitation, unexpected spring frosts, and drought. And with shorter and milder winters, insects and other grapevine pests are having longer life spans. 

The future of fine wine production is likely to shift due to climate change. Among agricultural products, wine grapes are one of the most sensitive crops to variations in temperature and precipitation. And the impact of climate change can affect the taste and quality of wine at almost every step of the wine-making process.

Warming temperatures could change the wine map.
Temperature and moisture are among the primary elements that affect the taste and quality of grapes, with growing season temperature being particularly important in determining what areas are suitable for growing high-quality wine grapes. 

• Warm climate wine regions generally have more consistent temperatures. A more gentle transition from summer to fall allows grapes to ripen longer (but at the same time allows more of the natural acidity to be lost, which is a negative). This produces wines that have more fruity flavors and less acidity. 

• Cool wine climate regions experience a steeper temperature gradient between summer and fall. Lower temperatures preserve acidity but the grapes take longer to ripen, producing more tart and acidic flavors.

With climate change, some iconic wine regions may become too warm and/or too dry for certain varieties of grapes. In the United States., the average growing season temperature (April-October) has risen 2.0°F (1.12°C) since 1970. Over that same time, the growing season has risen 2.9°F in California, which accounts for 85% of wine production in the U.S., and 12% of global wine production. 

For the highest quality wines, three conditions must be met: warm temperatures, low risk of frost damage, and no extreme heat. A warm growing season often means a good vintage. But long term warming trends could mean that vineyards currently producing a high quality Chardonnay may have to change to growing merlot grapes in the future. And when climate impacts the grapes in the vineyards, there are options in the winery. Winemakers can add color, acid, sugar, and other flavors through the addition of blends of other wine grapes. 

Grapes for lower quality wine—often called “table wine” or “jug wine”—can be grown across nearly all climate ranges. But premium wine grapes can only be grown in places that can support a delicate balance. Globally, wine grapes are grown in areas where the average growing season temperature (spring through fall) occurs within a narrow range of 18°F. For some grapes, such as pinot noir, the average temperature range is a much narrower 3.6°F.  According to wine experts like Dr. Greg Jones,  even a one degree temperature change outside of that range can make the difference between a poor, good, or excellent vintage.

Researchers found that extreme heat in the growing season due to climate change could reduce areas that are currently capable of producing premium grapes by 50%. Another study found that areas suitable for viticulture globally will decrease by 19% to 62% in major wine producing regions by 2050 under the RCP 4.5 scenario. 

Warming temperatures may force winemakers to move to cooler growing climates, whether at higher elevations or further north in the U. S. and Europe or further south in South America, Australia, and New Zealand. There are also potential water and land  conservation impacts. Wine producers may have to increase irrigation or try to cool grapes through misting or sprinkling. And vineyards are moving into places like the Greater Yellowstone ecosystem and Tasmania, causing new conservation challenges.

Nothing pairs well with notes of wildfire smoke. 
Devastating wildfires have swept through a number of major wine-producing regions in recent years, including Oregon, California, Greece, Australia, and Spain. Higher temperatures, drier conditions, increased fuel availability, and longer warm seasons—all linked to climate change—are increasing wildfire risk. Fires can ravage vineyards and destroy winemaking equipment and tasting rooms. But even fires at a safe distance from a vineyard pose a threat to wine grapes. Smoke exposure occurs when grapes are exposed to wildfire smoke while ripening, potentially creating an unwanted smokey, ashy taste and aroma. 

Expect increases in insect pests and insect-borne diseases. 
Warmer temperatures and more precipitation are projected to increase the likelihood of grape insect pests. Warmer temperatures allow many insect species to live longer and range further, while shorter, milder winters may not kill off harmful fungi or other pests.

Extreme weather events are a threat.
Vineyards are also vulnerable to the same severe weather events that can destroy other types of crops: early frosts, hail, heat waves, heavy precipitation and flooding, and drought. Extreme weather events have become more frequent or more intense with human-induced climate change. 

POTENTIAL LOCAL STORY ANGLES

How do I find out about wine production near me?
The American Winery Guide has a list of wineries by state. You can find local experts through viticulture or wine degree programs in your area or check in with academics at agricultural programs in your state. The Wine Association of America, publishes statistics on wine grape production by state and reports on the economics of the industry. Don’t know the difference between terroir and tannins? You can find help with wine terms here. 

LOCAL EXPERTS

SciLine, 500 Women Scientists, 500 Queer Scientists, Diverse Sources or the press offices of local universities may be able to connect you to local experts who can discuss the impact of climate change on agriculture.

NATIONAL EXPERTS

• Greg Jones, Ph.D., CEO, Abacela Vineyards
  Research interests include: Linking weather and climate with grapevine growth, fruit chemistry, and wine characteristics in regions around the globe
  Contact info and reports available at Climate of Wine. 

• Justine Vanden Heuvel, Ph.D., Professor and Chair, Horticulture Section School of Integrative Plant Science, Cornell University
  Research interests include: Optimizing flavors and aromas in wine grapes, improving the environmental and economic sustainability of wine grape production systems in cool climates. justine@cornell.edu

• Lee Hannah, Ph.D., Senior Scientist, Conservation International’s Betty and Gordon Moore Center for Science and Oceans
  l.hannah@conservation.org

• Pablo Andres Imbach, Ph.D., Principal Researcher Modelling, Global Center on Adaptation
  Pablo.Imbach@gca.org
  *Available for interviews in English and Spanish

METHODOLOGY

The national map showing the change in average temperature over the growing season (April-October, 1970-2020) was produced using NOAA/NCEI’s Climate Divisional Dataset. 

Climate‐maturity groupings based on growing season average temperatures. The horizontal bars represent the range of temperatures that each variety is known to ripen and produce high to premium quality wine in the world's benchmark regions. Please note that some adjustments may occur as more data become available, but changes of more than +/‐ 0.2‐0.5°C (+/- 0.3-0.9°F) for any variety are highly unlikely. The figure and the research behind it are a constant work in progress and are used with permission by the author, Dr. Gregory V. Jones (Jones, 2006; Jones et al. 2012).