‘My father once told me that if a winemaker could make one great vintage in his lifetime, he could die a happy man,’ says Jean-René Matignon. ‘I started making wine in 1985, and was fortunate enough to have a great vintage in 1988. After that superb year, I said to myself, ‘Well, I could tell my father I had made my one great vintage.’’

But for the technical director of Château Pichon-Longueville, one of Bordeaux’s most prestigious wine producers, it turned out that 1988 was just the beginning. ‘We had an even better vintage in 1989, another great one in 1990 and two more in 1995 and 1996.’ In fact, after almost 25 years at Pichon, he says, he has now made ten top-quality vintages. ‘This is something my father would never have dreamed of.’

Matignon’s experience isn’t unique. In the Mosel Valley in Germany, Ernst Loosen has a similar story to tell. ‘In the old days, we would have three good vintages in a decade, three or four bad vintages and three mediocre vintages. But since I took over from my father in 1988, we haven’t had a single bad vintage, and hardly any mediocre vintages.’

It’s the same in Rioja in Spain. ‘My predecessors used to regularly make adjustments in the cellar to compensate for poor-quality fruit,’ says Miguel Merino of Bodegas Miguel Merino. ‘But since I started making wine in 1994, we haven’t had a single bad vintage.’

In fact, during the past 15 years or so, winemakers from Rioja to the Rhine and Orvieto to Oregon have been enjoying unparalleled quality and consistency. Global warming, it seems, has made their lives easy, by creating the ideal conditions in many of the world’s established winemaking regions for grapes to reach their optimum ripeness.

However, research suggests they may not be celebrating for long. At a conference in Barcelona earlier this year, viticulturalists and climatologists told an audience that included some of the world’s most respected winemakers that if temperatures continue to increase at the current rate, the wine industry will change beyond recognition, and if people don’t start paying attention to what’s going on, it will be plunged into turmoil.

‘As temperatures rise in the hottest wine-producing areas,’ says Richard Smart, one of the world’s pre-eminent independent viticulturalists, ‘it will no longer be possible to grow wine varieties there successfully.’ In cooler and moderately warm regions, the prognosis isn’t much better. Although producers won’t have to stop making wine altogether, warns Smart, they will have to take drastic adaptation measures that will mean revising the styles that they currently produce.

For some producers, this will be a serious inconvenience; but for those in Europe that have built up reputations over decades – and sometimes centuries – based on established, regional styles of wine, it will be nothing short of disaster. Champagne will be a thing of the past, as will Bordeaux, Burgundy, Chianti, Rioja and just about any other European wine you can think of. ‘All of the regional styles will change,’ says Smart.

Smart’s assertions are supported by a growing body of scientific research that has emerged in recent years, primarily from US climatologist Gregory B Jones, professor of geography at Southern Oregon University. In the face of this evidence, winemakers are being encouraged to implement adaptation measures as soon as possible, in particular to look for new grape varieties that will be suited to higher temperatures.

However, these exhortations have met with strong resistance. Many winemakers have refused to accept Smart’s and Jones’s prognosis. They feel that the claims are exaggerated, and that the science on which future projections are based fails to acknowledge not only the complexities of the situation but also their ability to cope.

Adaptable fruit

It was the Ancient Greeks whofirst introduced viniculture to Italy, France and Spain, in around 750 BC. In the millennia that followed, generations of winemakers began to establish the regional styles so renowned today. The key to producing the best wine, they found, lay in identifying which grape varieties performed best in their particular environment.

We all know that fruits and vegetables requires a certain climate in which to grow – that peaches and olives prefer warmer temperatures than apples and pears, for example. But the grape is different. This very adaptable fruit can grow over a huge range of conditions, from the relatively cool, wet climate of southern England through the dry warmth of the Mediterranean to the humid heat of the tropics.

However, when you start to consider what you want to grow your grapes for, the opposite is true. Every variety requires specialised conditions in order to reach optimum ripeness; this is particularly important with wine grapes, where quality is valued perhaps more than in any other agricultural product.

It’s this principle that has contributed to the development of Europe’s distinctive regional wine styles. ‘During centuries of experimentation,’ explains Alun Griffiths, wine director of British fine wine merchant Berry Bros & Rudd, ‘winemakers found that Cabernet Sauvignon was well suited to conditions in the Bordeaux region, for example, and Chardonnay to those in Burgundy.’

However, it isn’t just the climate that dictates these established styles. A number of other, inter-related elements all have a part to play. These include the type of soil, its drainage and heat capacity, and the inclination and direction of the vineyard. Together with the climate, this complexity of influences is described collectively by the French term terroir.

‘This idea of terroir has a huge influence on the style of a wine,’ says Griffiths. ‘Take Chablis in Burgundy. The vineyards surrounding this village have a unique subsoil – a kind of clay – that lends itself to the production of extremely good dry white wine made from Chardonnay.’ It’s the unique combination of elements in Chablis that determine the character of the wine, he says. ‘If you go ten miles away, you could plant Chardonnay grapes, have the same climate and make the wine in exactly the same way, but you will never be able to make the same wine.’

Within all of the elements that constitute the terroir of a particular region or vineyard, climate is the most variable and, because it dictates the ripeness of the grapes, determines the quality of a particular vintage (see What makes a good wine?). ‘The ideal climate will allow the vine to develop complexity and to absorb as much from the soil as it can without getting over-ripe,’ says Griffiths. ‘It’s for this reason that the best wines are made at the edges of viticultural possibility, where there is just enough sunshine to get them ripe. In other words, if you tried to make Bordeaux wines nearer the equator, where it’s a few degrees warmer, you would have no trouble getting the grapes ripe, but you wouldn’t have the complexity and finesse that distinguish wines from that region. The same can be said for Champagne, Burgundy, the great German Rieslings. It’s an incredibly delicate balance.’

Unbalancing act

According to the latest assessment of the Intergovernmental Panel on Climate Change (IPCC), there is now ‘unequivocal’ evidence of global warming during the past 50 years. And just as meteorologists have detected these rising temperatures, so winemakers have experienced changes of their own.

While those such as Matignon, Loosen and Merino have been enjoying perfect ripeness, others in areas once considered too cool – England, Belgium and the Netherlands in Europe, Canada, southern Tasmania and southern Chile in the New World – have found their own viniculture is improving.

However, in warmer areas, growers have begun to experience problems. In parts of Spain, Portugal, Italy, Australia, Argentina, California and South Africa, producers have increasingly faced over-ripeness and the potential of unbalanced wines. In California’s Napa Valley, traditionally considered one of the world’s best regions for the Cabernet Sauvignon grape, the situation is so acute that up to 55 per cent of winemakers are having to remove alcohol and add acid to maintain freshness in their wines.



Enhanced ripening

According to Jones, the improvement in the quality of wine is a direct result of rising temperatures. His research shows that between 1950 and 1999, average growing season temperatures (AGSTs) in 27 wine regions around the world increased by an average of 1.3°C. And that, for every 1°C, vintage ratings by Sotheby’s and The Wine Enthusiast for the same period increased by 10–22 points.

The key, he says, is the influence of AGSTs on the ripening process. ‘Heat accumulated during the growing season enhances ripening,’ he says, ‘so the higher the AGST, the better the grapes’ development.’ However, too much heat means the grapes have high sugar levels by the time other desired elements – such as the colour, fruit and tannins – are ready, he adds. And that’s what growers in the warmer regions have been experiencing. ‘In such cases, the wine often ends up with too much alcohol and not enough acidity.’

Extrapolating on this relationship between AGSTs and quality, Jones has predicted how some of the world’s principal wine grapes will respond to further increases in temperature. Based on the accepted wisdom that every variety performs best within particular climatic conditions, he has defined temperature limits in which certain varieties can be grown successfully. He calculates that Cabernet Sauvignon, for example, performs in warm regions where the AGSTs range between 16.5°C and 19.5°C, and Pinot Noir in cooler areas where AGSTs are 14–16°C.

Jones predicts that even under the IPCC’s low-range scenario, future increases in the global average annual temperature will create conditions in established wine regions that may be unsuitable for their traditional varieties. ‘A one-degree change would mean that some areas would have to undertake considerable adaptation processes in the vineyard, while others may need to look to different varieties.’

However, he calculates that in many areas, AGSTs will increase by more than 1°C by 2049. Indeed, the average for the 27 regions he analysed will be 2°C, with South Africa experiencing the smallest (0.9°C) and southern Portugal the largest (2.9°C). Elsewhere in Europe, some of the highest increases will be felt in Rioja (2.5°C), Barolo in northern Italy (2.4°C), northern Portugal (2.4°C), Bordeaux (2.3°C) and Burgundy (2.3°C).

In many areas, Jones predicts, AGSTs will reach the upper end of the optimum ripening climate for the varieties grown there today. In Bordeaux, for example, where AGSTs averaged 16.5°C between 1950 and 1999, an AGST of 18.8°C by 2049 would be close to the limits for the red varieties grown there and would exceed those of the whites. In Rioja, an AGST of 19.2°C in 2049 would exceed the optimum ripening climate of the Tempranillo grape, which dominates production there.

In such cases, there will be wholesale changes in wine production as bands of suitable temperatures shift towards the poles. ‘We’re talking about a place such as Burgundy being as warm as Avignon in the south of France, and producers there not being able to grow Pinot Noir any more. We’re talking about Rioja becoming like La Mancha and points further south, which, today, can only make fortified wine.’

The implications of a 2°C change are without precedent, warns Smart, and will require winemakers to take drastic adaptation measures. ‘All the regional styles that have been established for hundreds of years will change. Cabernets produced in Bordeaux, for example, will be like those made in the south of France at present, which doesn’t have anything like the same reputation.’ For producers to maintain quality, he explains, they will have no choice but to change their style and find other varieties that are well adapted to the increased temperatures.

Red herring

Research into climate change and wine is still in its infancy. But Jones’s work on AGSTs and their impact on quality appears to have become the accepted wisdom and has certainly made the biggest splash in the media. However, many winemakers dispute his observations and are challenging his projections about the future. Concentrating entirely on increasing AGSTs, they say, is something of a red herring.

Château Pichon-Longueville’s Jean-René Matignon points out that producers already have to deal with significant variations in temperature at a local level. ‘On a summer’s afternoon, if I go from Pichon to [Château] Latour – which is just across the road – it can be up to two degrees warmer in Latour because it is protected from the wind.’ But anyway, he continues, exposure to sunlight during the ripening period is more significant than temperature and the accumulation of heat, as is a good fluctuation between daytime and night-time temperatures.

According to Bruno Prats, who spent 30 years at Château Cos d’Estournel in Bordeaux and now makes wine in Portugal, Chile and South Africa, AGSTs have no effect on quality. ‘What really has an influence are the weather conditions in August and September, when you need a little rainfall as well as warm temperature,’ he says. ‘That’s the time when the grapes are ripening. The weather in spring and early summer can have an effect on the volume of the crop, but certainly not the quality of the wine.’ However, he concedes that warmer spring temperatures can lead to an earlier harvest, which means grapes may consequently ripen under warmer conditions.

Matignon also disputes Jones’s conclusion that higher temperatures are the principal reason for the improvement in quality in recent years. ‘You must also consider what goes on in the vineyard. Winemakers know much more about the management of the vineyard than we did ten or 15 years ago,’ he says. ‘And we are investing much more in labour nowadays.’

When it comes to the future, all the winemakers and some of the climatologists to whom Geographical spoke agreed that it’s impossible to predict the impact of climate change on the status quo. But about one thing they seem certain: temperature projections alone will tell us little about the future viability of traditional wine-growing areas.

According to Hans Schultz, professor of viticulture at the Geisenheim Research Institute in Germany, although we know the lower temperature threshold of varieties’ suitability, we know little about their ability to cope in warmer temperatures. ‘All of the research so far only speculates on the upper limits of these varieties,’ he says. ‘So we can easily make assumptions about where it would be possible to grow Cabernet Sauvignon in new areas. But we don’t know whether it would still be suitable in Bordeaux.’

Jones’s idea of shifting temperature bands has led to speculation that classic wine styles could simply be moved into areas that were once considered too cool. But the complexity of the climatic influence upon viniculture means it would be impossible to produce Bordeaux-style wines in northern France, or Champagne in England, points out Olivier Brun of Perrier Jouët-Mumm. ‘It’s easy to look around the world and find regions where the temperature and even the soil might be suitable. But there are a huge number of other variables that influence the local climate and so affect the evolution of the grapes and the style of the wine.’

For a start, the topography of the vineyards has an enormous influence on local climate. ‘In Champagne, there is a great deal of air circulation because the vines are planted on slopes, so you have a big variation between day and night because the cold air is always going down and the warm air is always going up,’ Brun says. ‘But in Bordeaux, the vines are on plains, so you don’t get this effect.’

It’s also important to consider a region’s location, he says. Bordeaux receives 50 per cent more rainfall than Champagne, even though it’s hotter and more than 450 kilometres farther south. ‘If you have a
depression in Bordeaux, it’s always wet, because it turns from left to right and always carries humid air from the Atlantic. But when there’s a depression in Champagne, it tends to bring drier weather because the air comes from Poland and Russia.

‘Of course, southern England may be able to produce some very good sparkling wines in future,’ Brun says. ‘But because of its relative humidity, it could never reproduce the style of Champagne. And for the same reason, you will never be able to produce the Bordeaux style in the Loire or Champagne.’

In any discussion about global warming and climate change, scientists are keen to point out that they are different phenomena and that the latter is caused by the former. When it comes to winemaking, this is an important distinction.

Schultz points out that changes in rainfall patterns associated with climate change will often have more impact on production than increasing temperatures. ‘We are likely to see more heavy rainfall events in central European latitudes in the future such as those that caused floods in southern England last summer.’ If these occur during harvest, says Griffiths, they can devastate a crop. ‘Rainwater gets sucked up into the fruit and reduces their concentration,’ he says. ‘Sometimes the fruit can split, creating problems with rot.’ After catastrophic rains in the Rhône valley in 2002, he points out, the harvest was so bad that many producers refused to make wines under their own label.

At the other end of the scale, drought rather than over-ripeness may be the most pressing issue for winemakers in warmer regions. According to the IPCC’s predictions, southern Europe, and Spain in particular, will be increasingly affected by drought in the next 50 years.

However, there is still debate as to what impact drought will have in Europe. Pancho Campo, president of the Wine Academy of Spain, believes that southern regions can cope. ‘Here in Spain, our grapes have been grown under dry farming for centuries. Most of our varieties are well adapted to these conditions. They have a long growing cycle and so have developed extensive rooting systems that allow them to search for water deep in the soil. In this respect, I would be more concerned about places such as Burgundy and Champagne that grow cool-climate varieties, than Spain.’

Key to success

Climate change went to the top of the international agenda after the Stern Report was published in October 2006. But while the idea of adapting to inevitable change has become as important as mitigating its causes, few winemakers are willing to take drastic action at this stage. And who can blame them? For those who have built up a reputation based on the relationship between their vines and their terroir, replanting new varieties or moving their vineyards to cooler regions would effectively mean starting again from scratch.

As a result, the vast majority say they won’t be losing any sleep over climate change. ‘Why should we,’ they cry, ‘when we’ve recently been enjoying some of our best vintages ever?’

Some remain to be convinced that the recent increases in temperature are part of a permanent trend, particularly when 2007 produced the coolest summer in Europe since the early 1990s. Those who acknowledge the reality of global warming feel they can cope. Brun is particularly bullish: ‘I’m not convinced that climate change is going to end production in Bordeaux or Champagne. If you look at the past, we’ve had some years with enormous levels of sugar and we still produced good quality wine. So if we consider that, the change may have not only been 2, 3, or 4°C, but 5, 6 or 7°C.’

If temperatures continue to rise, many producers feel viticultural techniques will be the key to future success. Ernst Loosen, who took over his father’s Riesling vineyards in the Rhine and Mosel valleys in Germany in 1988, has also been making wine on the US west coast in the Columbia Valley, Washington state, since 1999. This experience, he says, has taught him how to treat Riesling, traditionally a cool-climate variety, in hotter climates. ‘Columbia Valley is basically a desert, with almost three times the number of sunshine hours as we have in the Mosel.’ In these conditions, he says, it’s possible to reduce the rate at which the grapes ripen by hanging them higher on the vine. In this way, the grapes have long enough on the vine to get the aromas and structures he wants, but without getting over-ripe.

Other winemakers mention similar techniques, including changing the direction of vineyards, developing leaf canopy, altering the clone or rootstock, and growing grass between the rows to compete for nutrients in the soil. ‘I have no doubt that when it comes down to it, the winemakers who have the most skill in the vineyard are still going to be able to make good quality wine,’ says Loosen. ‘And in this respect, climate change could be a good thing for the industry as a whole as it will encourage us all to pay more attention to the way we grow our grapes.’

One of the few producers to have begun more serious adaptation measures is the Torres family, one of Spain’s biggest and best known winemakers, which has planted vines in the cooler areas of northern Catalunia near the foothills of the Pyrenees. But many of Europe’s wine growers may not be in a position to take such steps, says Griffiths. ‘Many of them are small producers who don’t have the option of relocating because they don’t have the resources,’ he says.

Perhaps the most significant step towards adaptation will be taken by the regulating bodies in Europe, which are considering following the move made by the French regulators in late 2006 when it reversed hundreds of years of tradition by allowing farmers to irrigate their vines, albeit at the discretion of local authorities.

Whatever the future holds, one thing is clear: most European producers may be happy to experiment in the vineyard, but they will be extremely reluctant to abandon their traditional styles by taking such drastic steps to adapt as moving their vineyards or replacing their traditional varieties.

But Jones feels winemakers shouldn’t be held back by tradition. ‘We can’t afford to be sentimental,’ he says. ‘There is a social construct that we have today that makes people think we’re steadfast and that Burgundy will always be Burgundy and so on. But we have to adapt and work with the opportunities that arise. Who knows – we may find that in 30 years, the Puget Sound in Washington state is producing better Pinot Noirs than Burgundy?’

If the debate appears opaque and somewhat inconclusive, that’s because opinions are still divided. But in the midst of it all, Campo offers a sobering note of warning. ‘A lot of this discussion may become immaterial. If we get to the point that Pinot Noir can no longer be grown in Burgundy and producers there have to change their grape varieties after trying all the techniques that are available, trust me, we won’t be worrying about wine. We’ll be worrying about other things that are much more important. We’ll be worrying about survival.’

What makes a good wine?

When discussing the qualities that a good wine possesses, Alun Griffiths, wine director of Berry Bros & Rudd, likes to make an analogy with music. ‘A good pop song might be instantly recognisable and have a catchy tune that has an immediate effect on you. But classical music is something that you can return to again and again and get more pleasure from it, and perhaps a different kind of pleasure each time.’

And it’s the same with wine, he says. ‘There are simple, everyday wines that might be very good, but are somewhat one-dimensional – fruity, with one dominant flavour. They might be attractive and charming, but there is no great depth to them.’ The best wines, he continues, will demonstrate a balance between a number of different elements. ‘There’s the fruit – which might be peaches and apricots in a white wine or cherries and blackcurrants in a red. Then you have alcohol, sugar, acidity and, in red wine, tannin. In some cases, there is also a minerality that reflects the soils on which it is grown.’

It’s the balance and interplay between these elements that is the key to a good wine, Griffiths continues. ‘If any one is too pronounced, then you probably won’t enjoy it – if there’s too much acid, it will taste vinegary, for example, and not enough, it will be flabby.’ But just like music, he says, it’s entirely subjective. ‘It all comes down to taste. There are those in the industry who can say that one wine is better than another, but at the end of the day it’s down to the individual, and not for us to say that anyone is right or wrong.’

European agriculture and climate change

Away from the peculiarities and constrictions of the wine industry, it seems that Europe’s farmers have already begun adapting to climate change. Generally speaking, there is a north–south divide, with those in northern regions enjoying higher yields from increased temperatures, while those in the south are beginning to suffer from higher temperatures and increased periods of drought.

To date, the biggest changes have been seen in cereal crops in northern Europe. In Scandanavia and the UK, for example, high-yielding silage maize has replaced traditional dairy fodder crops such as whole-crop cereals and fodder beet. And in Belgium, grain maize – used to feed pigs and other non-ruminant livestock – accounted for almost 20 per cent of total cereal land in 2006, compared to virtually zero in 1961. Yields of the same crop have increased by more than 250 per cent.

However, it isn’t all good news. Increased winter rainfall of up to 30 per cent has forced farmers in low-lying coastal regions of Denmark, the Netherlands and Belgium to modify their drainage systems, and in some cases abandon cultivation altogether. There is also evidence that the same phenomenon has increased nitrate and phosphorus leaching and could be responsible for up to 40 per cent of such agricultural pollution.

In southern Europe, while there have been some increases in yields, agronomists say that the biggest changes are yet to come. ‘There is no doubt that drought will be the biggest factor in countries such as Spain, Greece and Italy, in some parts of France and parts of the Balkans, which already rely on irrigation to cultivate certain crops,’ says Jørgen E Olesen, professor of agroecology and environment at the University of Aarhus, Denmark. ‘It’s not so much the general changes in temperature and rainfall that are the problem, but the extreme events.’

Spain and Greece already use more than 80 per of their fresh water for irrigation, Olesen points out. ‘As we see more drought, water will become more precious, and it wouldn’t be worth irrigating cereals and other cheap commodity crops.’ In this case, he says, farmers are likely to switch from irrigated spring and summer cropping of maize and soya bean, for example, to dry-land or rain-fed winter crops such as wheat. ‘The problem here is that the yields will be substantially lower.’

Across Europe, we’re likely to see crops commonly associated with the Mediterranean – aubergines, peaches, tomatoes – moving farther north as Spain and Italy becomes hotter and drier. But Olesen doubts they’ll reach northern regions, as has been suggested. ‘It all depends on how much the climate changes, but I’m not sure we’ll see such a dramatic shift. It’s more likely that the farmers in the north will benefit from higher yields of those crops they are already growing and from being able to plant higher yielding crops such as the maize.’

October 2008