Global warming could have a detrimental effect on wine from the warmer regions, such as France and California, while perhaps leading to a boom in grapes from cooler parts of the world, according to a new study reported at the annual meeting of the Geological Society of America.
Gregory Jones of Southern Oregon University and his colleagues studied 27 of the world’s top wine regions and compared their region of origin with growing season temperatures and quality of the wine for the last 50 years. His results are enough to chill even vintners in the warmest of climes. Rising temperatures he claims have already impacted vintage quality and over the next fifty years, if climate models ring true, then the warmer wine regions may lose out to regions that are currently cooler.
Gregory Jones
Jones, who carried out the research with colleagues Michael White of Utah State University and Owen Cooper of the University of Colorado/NOAA Aeronomy Lab, explains that Grapes are a good indicator crop, because the majority of wine grapes are grown almost exclusively in narrow climatic zones in temperate, Mediterranean-type, climates and growers and drinkers alike can be obsessive in their rating of quality. Wine grapes provide a particularly good indicator of how climate can affect a grape harvest, that season’s vintage and by extrapolation the impact on other crops in the same region.
Rather than getting their hands dirty cracking open bottles taste-testing, the researchers used records of Sotheby’s 100-point vintage rating scale data (where wines scoring over 90 are excellent to superb and under 40 are disastrous) along with climate records dating back to 1950 to look for trends in wine quality or growing season temperatures. What they found was an average temperature rise of 1.26°C in that period and higher vintage ratings. According to Jones, there have been no negative effects on wine quality so far. But, if temperatures continue to rise, those same top class wines may start to suffer.
Hadley Centre, Met Office (Credit: Hadley Centre, Met Office)
Those wine-growing regions that are currently warm could face challenges in terms of overripe fruit, added water stress, and increases in diseases and pests. On the other hand, warmer temperatures could mean that currently cool regions would experience more consistent fruit ripening and less year-to-year variability in their wine quality. While regions like California, southern Europe, Australia, and South Africa have basked in the glory of warm climates that make fine wine, global warming could leave them high and dry, while allowing Swedish Chardonnay to shine.
Hadley Centre, Met Office (Credit: Hadley Centre, Met Office)
Jones points out that while technological improvements in grape growing and wine making have led to higher quality wines over the period he and his colleagues have studied, climate is the wild card that determines year to year quality differences. The HadCM3 coupled atmosphere-ocean general circulation model (AOGCM) developed at the Hadley Centre in the UK has helped the team produce predictions about wine quality. While the wine regions warmed at different rates over the next 50 years, the average warming is 2.0 °C by 2050, Jones told Spotlight.
Fine wines may get better with global warming (Credit: Dan Lednicer; https://www.sciencebase.com/dan_lednicer_bio.html)
For example, Italy’s Chianti region is presently very warm in the summer, but could get hotter, increasing pest damage and leading to earlier harvests. In contrast, Germany’s Rhine Valley could benefit from greater ripening potential, although might ultimately have to swap to different grapes as the climate warms. The apparent warmer temperatures may in part already have allowed grapes to grow at higher latitudes and elevations, where once it was too cold. For instance, vineyards are on the rise in southern England. Indeed, this year’s harvest looks to be one of the best in England, adds Jones.
Ploughed fields may give way to acres of vines in colder climes (Credit: David Bradley)
The bottom line, says Jones, is that growers need to pay attention to what might be happening in terms of climate. In the coming 20 to 30 years they may have to work to replace varieties or change management strategies, he says.
Further reading
Gregory Jones
http://www.sou.edu/Geography/JONES/jones.htm
Michael White
http://www.gis.usu.edu/~mikew/
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