Wine Grapes: Vulnerable to High Temperatures
As temperatures rise in response to increasing greenhouse gas emissions, effects of climate change on the agriculture industry will become more pronounced. The largest impact will fall on plant species that are especially sensitive to changing weather patterns, such as the wine grape (Vitis vinifera). High temperatures during fruit ripening adversely affect wine quality and thus its market value. For example, premium Petit Verdot wine grapes from the Napa Valley of California fetch an average of $5.95 per kg, whereas mixed red wine grapes from only 150 km away in the hotter San Joaquin Valley garner only an average of $0.24 per kg. 
As a consequence of global warming, locations suitable for growing premium wine grapes will shift to higher latitudes and from inland to coastal areas. According to the forecasts of two climate models (the United States Department of Energy’s Parallel Climate Model and the United Kingdom’s Hadley Centre HadCM3 model), wine grapes in all of California except along the coast will ripen 1 to 2 months earlier and at higher temperatures by the year 2100.  Total premium wine grape production in the United States might decline by up to 81%.
 California Department of Food and Agriculture (2007) California Agricultural Resource Directory 2006, CDFA, Sacramento, CA.
 Hayhoe, K., D. Cayan, C. B. Field, P. C. Frumhoff, E. P. Maurer, N. L. Miller, S. C. Moser, S. H. Schneider, K. N. Cahill, E. E. Cleland, L. Dale, R. Drapek, R. M. Hanemann, L. S. Kalkstein, J. Lenihan, C. K. Lunch, R. P. Neilson, S. C. Sheridan, and J. H. Verville (2004) Emissions pathways, climate change, and impacts on California. Proceedings of the National Academy of Sciences of the United States of America 101:12422-12427.
This is an excerpt from the book Global Climate Change: Convergence of Disciplines by Dr. Arnold J. Bloom and taken from UCVerse of the University of California.
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