Paolo Pittaro, of the Pitars winery, holds a bunch of grapes in his vineyard. Picture by Chico Harlan for The Washington Post

In a region celebrated for the prosecco and pinot grigio it ships around the world, Italy's particularly sensitive white wine grapes have become a telltale of even gradual temperature increases - a climate slipping from ideal to nearly ideal. 

Vintners and farmers are noticing more disease, an accelerated ripening process, and, most viscerally, a surge in the number of grapes that are singed by the intensifying summer heat.

Growers say they have little choice but to try to manage. 

Some are experimenting with new watering systems and shade strategies.

But they debate whether the treasured aromas and flavour notes of their wines are already changing - and whether they'll one day lose out to colder-climate producers whose wines once were scoffed at.

Wine ages in bottles at Villa Sandi, which produces multiple varieties of sparkling and still wine. Picture by Chico Harlan for The Washington Post

Climate change is only beginning to reorder the global wine industry, altering the patterns of how and where grapes are produced, and testing whether the world's iconic regions can find ways to adapt.

 Many factors influence wine and its taste. 

Yet because of rising temperatures, some of Europe's biggest producers are buying up land in the Pyrenees foothills, in northern China, and in southern England - where the climate now resembles the French Champagne region of the 1970s.

"So what happens to the existing regions that are famous?" said Elizabeth Wolkovich, a researcher at the University of British Columbia. "If they don't make changes, or they don't make them fast enough, I think there will be a reshuffling of where the great wines are made."

If the planet's climate warms in coming decades as much as most scientists predict, there will be more pressing concerns than whether "you'll have a good Bordeaux from Bordeaux," Wolkovich said.