ABC Australia, Wednesday, 5 November 2003
Global warming makes a better wine vintage
The good news is climate change has grapes blooming. One positive side to the rise in global temperatures is that it can lead to better tasting wine, although warmer weather could also mean trouble for some famous wine-growing areas, U.S. researchers report. Dr Gregory Jones from the Southern Oregon University and colleagues presented the results of their study comparing the results of vintage wine tasting and climate trends at this week's annual meeting of the Geological Society of America being held in Seattle, Washington.
The researchers looked at 50-year records for climate data and matched them with the quality of wine as measured by Sotheby's 100-point vintage rating scale. The Sotheby's scale ranges from under 40s - meaning 'disastrous', to over 90s - meaning 'excellent to superb'. Jones and colleagues found an average global temperature rise of two degrees coincided with higher vintage ratings. The study included three wine growing regions in Australia. "There were no negative impacts," Jones says. "Overall, the results indicate that the majority of the regions have experienced growing season warming that is related to better overall vintage."
However, say the researchers, further predicted temperature rises of two degrees may stress wine growth in areas currently famous for producing excellent wines. Regions famous for a particular grape may have to change varieties, which could cause a change in cultural identity, Jones says: "In the coming 20 to 30 years they may have to work to replace varieties or change management strategies."
Italy's famous Chianti region, for example, would face pest problems related to earlier harvests as the weather becomes hotter. Cooler wine growing regions, on the other hand, could benefit from balmier climates, with fruit ripening more consistently leading to less variability in wine quality from year to year. Already, vineyards are on the rise in Southern England. The researchers say wine is a particularly good crop for probing the effects of climate change on agriculture as a whole. This is because years of specialisation in wine growing regions have made crops particularly susceptible to risks associated with climate change. And years of experience of wine tasting provides information on small variations in the quality of the wine. "Grapes are a good indicator crop. Wines are almost obsessively tasted and rated for quality, and are a particularly good indicator of changes that are probably effecting other crops in the same area," says Jones.