Sparkling wine undergoes an early fermentation process at the Ridgeview Wine Estate in East Sussex, England. Warmer summers are producing wines competitive with some from France. (GRAHAM BARCLAY/BLOOMBERG NEWS)

Blessed with soil similar to France’s Champagne region, vineyards in England nevertheless produced decades of low-grade goop that caused nary a Frenchman to tremble. But a Great British fizz boom is underway, with winemakers crediting climate change for the warmer weather that has seemed to improve their bubbly.

Increasingly hospitable temperatures have helped transplanted champagne grapes such as chardonnay and pinot noir thrive in the microclimates of southern England, touching off a wine rush by investors banking on climate change. Once considered an oxymoron, fine English sparkling wine is now retailing for champagne prices of $45 to $70 a pop. In recent years, dozens of vineyards have sprouted in Britain’s burgeoning wine country, with at least one traditional French champagne maker doing the once-unthinkable — scooping up land to make sparkling wine in England.

British bubblies have bested global rivals in international competitions and were served in lieu of champagne at last year’s Diamond Jubilee celebrating Queen Elizabeth II’s 60th year on the throne. A small but growing export market has found English sparkling wine on store shelves and restaurant menus in Japan, Hong Kong, the United States and Australia.

Temperatures here are about 11 / 2 degrees warmer than they were four decades ago, significantly improving harvests. Many climatic variables affect wine grapes. But by at least one measure — average temperatures during the grape-growing season, which are now routinely above 55 degrees here — southern England is beginning to look more like the Champagne region of years ago.

“Think of what French champagne was like in the 1970s,” Mark Driver said as he gazed out at the newly planted vineyard he is building within scenic eyeshot of the English Channel. “That’s what England is producing now.”

The global wine business is fast becoming a bellwether for scientists monitoring the ability of industry to adapt to climate change. Winemakers and agricultural experts say warmer, shorter growing seasons are affecting the characteristics of some well-known wines and challenging celebrated grape regions.

In Italy and Spain, vineyards are seeking higher altitudes to cope with greater sugar and alcohol levels from ever more sun-drenched grapes. In France, slightly higher temperatures are accelerating annual harvests, forcing wine producers in some areas to grow more natural canopy, reduce pruning and, in extreme cases, phase out more fragile varieties of grapes.

The English, meanwhile, are adding their names to the expanding global wine list of colder-climate producers. In 2011, Wine Spectator magazine added a Patagonian malbec to its top 100 wines, and the cool-climate vineyards of New York’s Finger Lakes are gaining attention for world-class Rieslings.

Some experts contend that more warmer-season vintages have largely meant a broader range of better wines from most growing regions, old and new. “From warmer weather, I think what you’re seeing is a change in character in some wines rather than one of quality at this point,” said Dana Nigro, senior editor at Wine Spectator. “We are seeing fewer and fewer mediocre wines.”

One study released this month by a team of climate-change scientists suggested that by 2050, the global wine industry would be turned upside down. The study, which appeared in the Proceedings of the National Academy of Sciences, predicted that the Mediterranean region, for instance, would lose vast areas suitable for wine growing unless it boosted irrigation and took other steps, while swaths of Northern Europe would have ideal temperatures for growing grapes. Critics assailed the study, saying that it turnedguesswork into science and that there is not enough evidence to support claims of such dramatic changes ahead for the wine industry.

The global-warming debate

Yet within the industry — just as among the public — a heated dispute has broken out over the role of global warming on winemaking. In places such as California, where irrigation is more common, grower associations insist there has been almost no impact. But in some parts of Europe where irrigation is far more rare — such as England and France — the changes appear more pronounced.

“We can already see in Europe that the harvest date is two weeks earlier than two or three decades ago, and that, it seems, is at least partly due to climate change,” said Serge Delrot, research director at the Grape and Wine Sciences Institute in Bordeaux. “All regions [in France] are looking at this seriously now.”

Changing conditions also seem to be benefiting Champagne — the northernmost of France’s major wine regions. Julien Duval-Leroy, secretary general of the Duval-Leroy champagne house, said record heat in 2003 yielded a vintage with a more alcoholic aftertaste. But overall, he said, other climatic factors — including moisture and wind — have combined with slightly higher temperatures to provide some banner vintages.

“2008 was something sublime for your cellar,” he said.

He — like other French winemakers — has a hard time taking English fizz seriously. “I suppose it could be fine for domestic consumption, but not much beyond that,” he said.

The English beg to differ.

For decades, grape production in the pea-green hills of southern England was largely limited to a Frankenstein’s monster of German hybrids that did well in colder climes. In 1990, an American couple began producing the first English sparkling wines from champagne grapes brought from France. Their timing, it appears, was impeccable.

Slightly warmer temperatures were making the region increasingly ideal for champagne grapes, which can thrive with less sunlight and in milder weather than red wine grapes or even those used to make some still white wines. Under widely recognized trade treaties, the word champagne is reserved for sparkling wine produced from the celebrated region in France of the same name. Spain, meanwhile, has become known for cava and Italy for prosecco. But British vineyards remain at odds over what, if anything, to dub English bubbly — with none of the names floated, including Britagne and Merret, gaining much traction.

The role of technique

Winemakers here contend that a combination of more sophisticated vineyards and a changing climate has improved quality and consistency. Grapes are maturing earlier, curtailing the threat of frosts and allowing greater absorption of sunlight in the key final weeks before harvest.

French winemakers, however, counter that England’s relatively higher moisture levels will limit its potential as a fine-wine region. In addition, here as elsewhere, weather patterns have appeared to become more erratic — last year, for instance, was the wettest on record in a century.

For the vineyards at Nyetimber — one of the most celebrated English sparkling-wine houses — bad weather meant a near-total loss of last year’s grape crop. “Climate change is going to have its challenges,” said Cherie Spriggs, the company’s winemaker.

Nevertheless, newcomers such as Driver are convinced that climate change is leveling the playing field for English wines. The 48-year-old attended a viticulture course in nearby Brighton and plunked down $15 million to set up one of Britain’s largest vineyards last year. Armed with oak barrels, equipment and a chief winemaker all imported from France, he is set to start producing his first wines this year.

“The English weather is finally going to be on our side,” he said, walking on the sloping Downs of East Sussex and pointing to the shining sun.

While French winemakers appear to see little threat from the English, a measure of resentment seems to be brewing.

Jonathan Medard, a 38-year-old French winemaker hired by Driver, said he entered a bar in Champagne last year with his English boss. When the bartender, whom he had long known, asked what he was doing these days, Medard replied: “I am making sparkling wine in England.”

Medard said the French bartender’s eyes narrowed before he said “Shame on you” and stormed off.

Eliza Mackintosh contributed to this report.