The last of California's summer wine?

The lush vines of California are among the most iconic images of America, with the perfect climate between the baked Central Valley and the cool Pacific coast enabling the area take its place as one of the great success stories of the boom in new-world wines.
The industry is worth billions of dollars a year and has starred in its own movie, the wine-buff-midlife-crisis road-trip hit Sideways. But just as American wines from the now famous Napa and Sonoma valleys and other enclaves have established their place at the world's top tables, a new report has warned that global warming may destroy the industry.
The study forecasts that by the end of this century up to four-fifths of the best vine-growing areas will no longer be able to grow their premium grapes because of the steady rise in very hot days, when temperatures pass 35C. And with California now in a state of emergency because of a two-week heatwave in which temperatures have soared to 49C, and which has been blamed for killing more than 120 people, the wine industry faces an imminent crisis.