(YahooFood) - Is this the long goodbye to Bordeaux, Napa Valley, and the Rhone?

Ever since a massive heat wave hit Europe’s vineyards in 2003, winegrowers there have been racing to fend off the effects of global warming. Yet even they were stunned by a report last year in the Proceedings of the National Academy of Sciences, which predicted that by 2050— well within many of our lifetimes—most of the great wine regions of Europe will have totally lost their charms.

Call it “Grapocalypse Now.” Is the future of wine really in jeopardy or is this all a bunch of needless doomsday scrambling?

"Nothing we’ve heard since publication has made us change our minds," says the paper’s lead author, Dr. Lee Hannah, a senior scientist for climate change biology at Conservation International.

"The models we use predict mean climate changes, but bad weather spikes will make some years worse,” he adds.

Under the scenario painted by Hannah and his colleagues, Europe’s Mediterranean areas (the places where the best wines are now made) will be hardest hit: Tuscany, Bordeaux, the Rhône Valley. “And the French regions are tied to growing certain varieties which they can’t change,” Hannah notes. “But non-Mediterranean France will do pretty well, as the suitability [for grape production] drop-off won’t be as severe.”

Northern Europe, including England, Baltic Germany, and even Scandinavia, may become prime wine producers in the decades ahead. Hannah’s suitability maps also show dire consequences for parts of California and southern Australia.