Global warming could alter the US premium wine industry within 30 years

The amount of high-value Northern California land suitable for growing premium wine grapes could be cut in half by 2040 because of global warming, researchers say. Their findings are based on the conservative assumption that average global temperatures will rise about 2 degrees Fahrenheit during that time.

Higher temperatures could hurt California and other premium wine growing regions of the United States in the next 30 years, according to a new study led by Stanford University climate scientists.

"I was surprised that local temperature changes could have such a big impact on an important industry with only 1 degree Celsius of global warming," said Noah Diffenbaugh, an assistant professor of environmental Earth system science and a center fellow at the Woods Institute for the Environment. (Photo by Linda A. Cicero / Stanford News Service)

Writing in the 30 edition June of Environmental Research Letters, the scientists report that by 2040, the amount of land suitable for cultivating premium wine grapes in high-value areas of Northern California could shrink by 50 per cent because of global warming. However, some cooler parts of Oregon and Washington state could see an increase in premium grape-growing acreage due to warming, according to the study.

These results follow the researchers' 2006 climate study, which projected that as much as 81 per cent of premium wine grape acreage in the country could become unsuitable for some varietals by the end of the century.

"Our new study looks at climate change during the next 30 years – a timeframe over which people are actually considering the costs and benefits of making decisions on the ground," said Noah Diffenbaugh, an assistant professor of environmental Earth system science and a center fellow at the Woods Institute for the Environment at Stanford. Diffenbaugh co-authored both studies.

Climate change, from global to local
Most American wine comes from the West Coast. California alone produces on average more than 5 million gallons per year, accounting for about 90 per cent of the nation's total wine production, according to the Wine Institute, a trade organisation representing California winemakers.