By Sybille de La Hamaide
PARIS (Reuters) - It's a $200 billion (£133 billion) industry that prides itself on being rooted to a particular spot and doing things they way they've always been done. But global warming is forcing the world's wine growers to change.
As a U.N. conference in Paris next week tries to limit climate change, wine makers from France to Australia are already changing their time-honoured methods, or even uprooting whole vineyards, as long-established weather patterns alter and the temperature rises.
Already, English sparkling white wine and even Nordic reds and whites have claimed shelf space in the specialist stores. But increasingly, many of the more traditional labels may begin to taste different as drier, hotter summers change the properties of their grapes.
Warmer temperatures ripen the grapes faster: the harvest in Bordeaux already takes place about 10 days earlier than in 1980; in Champagne, 15 days; and in Australia, eight.
According to the Intergovernmental Panel on Climate Change, 1983-2012 is likely to have been the warmest 30-year period of the last 1400 years in the Northern Hemisphere. And while global average temperatures rose 0.7 degrees Celsius (1.3 Fahrenheit) between 1850 and 1986, they are predicted to leap 0.5C in the next 20 years alone.
Faster growth tends to boost the grapes' sugar content, and therefore the alcohol level, and reduce the acidity.
This is generally good news in cool regions such as northern Europe, including Germany and the French regions of Champagne and Val de Loire, although it may subtly change the taste of their wines.
Southern England, the northernmost frontier for vineyards just a generation ago, has seen a rapid expansion since the 1980s thanks to its warmer summers, and especially since 2000, predominantly in sparkling wines that compete with Champagne.
"In some areas they have been making a similar kind of wine for hundreds of years, so I'm sure they will cope - but it is an opportunity for us in England to make a unique kind of wine," said Sam Lindo, chairman of the UK Vineyards Association.
NOT JUST POLAR BEARS
England has long since abdicated the 'northernmost' title. Warmer temperatures and new vines that can resist colder winters are bringing wine production into Nordic countries, although the risk of a soggy summer is still a high one there.
"There is this myth about the cold weather here, the moose and the polar bears," said Goran Amnegard, from the Blaxsta winery near the Swedish capital Stockholm, which sells as far afield as Hong Kong. "We have had more or less Mediterranean summers."
But many traditionally warmer regions could do without the extra heat.
Australian winemakers, for instance, are moving south to the island of Tasmania.
Average temperatures in Australia's main wine regions are projected to increase by between 0.3C and 1.7C by 2030, reducing grape quality by between 12 and 57 percent, according to the national science agency, CSIRO.
Treasury Wine Estates (AX:TWE), the world's largest standalone wine company, sold its vineyards in the Hunter Valley north of Sydney in 2013, worried that the region would become "hot and dry and expensive", and bought White Hills in Tasmania.
Some producers in Chile, the world's fourth largest wine exporter, have also moved their vineyards to cooler, wetter climes further south. Others are moving their vines uphill.
Shifting whole vineyards is not so easy, though, for the world's top three producers, France, Italy and Spain.
In France, for instance, half the output is regulated by the "Appellation of Controlled Origin" or AOC system, born in 1935, which defines each label by its "terroir", or unique soil, climate, and viticulture practices.
Much fine-tuning has already been done, in irrigation, planting density and pruning. But any substantial change, such as changing a grape variety, means applying for a new AOC designation with proof of established quality, a process that takes years.
TOO MUCH ALCOHOL
And in warmer regions where sugar levels are already high, the extra alcohol content of the resulting wine could also become a problem.
"If wines are too warm, too alcoholic, it will hold back consumers; one or two glasses and they will stop," said Nicolas de Saint-Exupery, a producer in the southern French region of Languedoc, seen as vulnerable to global warming.
In these areas, winemakers and scientists are working out ways to reduce alcohol while preserving the flavour. This might mean shading the grapes, changing irrigation practices, or even artificially removing alcohol from finished wine.
The European season also appears more unpredictable than before.
"Changes in the climate used to be sporadic; now every summer is different," said Fabio Lambruschi, producer of white Vermentino wine in the Italian region of Liguria.
Italy is the world's largest wine producer, and universities and winemakers there are trying to cope with the changes by breeding new vines that are resistant to diseases linked to bad weather.
The industry's collective memory is still traumatized by "phylloxera", a tiny pest that ravaged vineyards across Europe in the late 19th century.
Although the Great Wine Blight all but wiped out French wine growing, it did eventually recover, and the head of the International Organisation of Vine and Wine (OIV), Jean-Marie Aurand, says his industry is still resourceful.
"We have today other strains and cultivation techniques, so I'm not worried in the short or mid-term," he said.
The long term may be another question altogether, though. The Paris conference already seems certain to miss, by some distance, its goal of limiting a rise in the global average temperature to 2C above pre-industrial times.
Half that rise has already happened. Another two degrees, says Jean-Marc Touzard, coordinator of a programme on wine and climate change at France's INRA research institute, will simply "blow up the French vineyard map".