"We focused on these counties because their mild climates have made them major sources of high-quality grapes, and because they represent both cool and warm growing conditions," Diffenbaugh said.
But that could change, and soon.
"There will likely be significant localized temperature changes over the next three decades," Diffenbaugh said. "One of our motivations for the study was to identify the potential impact of those changes, and also to identify the opportunities for growers to take action and adapt."
Climate change for lovers of fine wine
The study was based on the assumption that there will be a 23 percent increase in atmospheric greenhouse gases by 2040, which could raise the average global temperature by about 1.8 degrees Fahrenheit (1 degree Celsius) a conservative scenario, according to Diffenbaugh. "World governments have said that to reduce the negative impacts of climate change, global warming should be limited to an increase of 1 degree Celsius," he added.
To predict how much land area will be suitable for premium wine grape cultivation in coming decades, Diffenbaugh and his colleagues used a very high-resolution computer model that incorporated local, regional and global conditions, including factors such as coastal wind speeds and ocean temperatures. The researchers compared their simulations to actual weather data collected between 1960 and 2010 to see if their model could accurately "predict" past temperatures.
Using the climate model and the historical weather data, the researchers predicted that by 2040, all four counties are likely to experience higher average temperatures during growing seasons, along with an increase in the number of very hot days when the thermometer reaches 95 F (35 C) or above.
In the experiment, the scientists divided premium grape varieties into separate categories based on their to
|Contact: Mark Shwartz|