Wine makers are notoriously dependent on tiny subtleties of environment (temperature, soil, weather) to create the terroir that gives each wine its particular profile. Rising global temperatures will mean that traditional wine regions, especially in Europe (France, Italy, etc) will suffer as the suitable territory moves further north and to higher altitudes.
According to this study projecting the impact of climate change on worldwide wine production by the year 2050, Europe will be the hardest hit, with up to an "85 percent decrease in production in Bordeaux, Rhone, and Tuscany". Australian wine would be next in line (down 74%), followed by California (down 70%).
One possible bright side: higher-latitude countries like the UK could experience a never-before-seen grape boom. But be honest: Do you really want Brits responsible for your wine?