Hot Topic - Global Warming

  • Thursday 17 July 2008

How winemakers are
coping with climate change,
and does it mean an
end to our classic wine styles?

onsider this: Bordeaux

may already have had its best

vintages for Cabernet.’ This

blunt analysis, from Australia’s

flying ‘vine doctor’ Richard Smart,

probably gave more pause for thought

than any of the swirling maps, emotive

speeches or lists of data presented at the

second Climate Change and Wine

Conference, held earlier this year in

Barcelona. Warming to his theme,

Smart added: ‘Maybe we’ll think

of future vintages as “postclassic”,

and therefore

worth less.’ If anything

more was needed to fuelthe spiralling prices of 2005 Bordeaux,

there it was. But the larger question is

this: if climate change really does mean

Bordeaux’s days as a fine wine region are

numbered, does the same fate await the

rest of Europe’s great vineyards?

‘If climate change really does mean Bordeaux’s days

as a fine wine region are numbered, does the same

fate await the rest of Europe’s great vineyards?’

The Europeans show more optimism

about the future than winemakers Down

Under. When Bordeaux-based international

consultant Michel Rolland spoke at the

Barcelona event, his tone was more

relaxed than Smart’s: ‘Climate change is

not changing our lives day to day,’ he said,

‘We’re making wines in the same way. We

have more sugar because we want more

sugar; we have more silky tannins because

of what we are doing in the winery.’ It

sounds rather glib, but Rolland does have a

point. So far, climate change has favoured

production of the style of wines the world

loves, and for which Rolland is acclaimed.

Why would he – or we – be complaining?

Well, for a start, fashions are turning

away from the more full-bodied, riper

styles that are high in alcohol, and there

is a surge of rosé and flavour-light whites,

such as Pinot Grigio. Is it even going to

be possible in the future to produce crisp,

lightweight, yet high-quality wines in

the cool European climates of today?

According to Hans Schultz of the

Geisenheim Research Centre in

Germany, higher temperatures have

already changed some styles of wine. ‘The

wines from classic, cool-climate grape

regions used to be thin and low in

alcohol,’ he says, ‘but now, ripening is

much more consistent.’

A growing problem

Perhaps we have been slow to pick up on

the relatively gradual effects of climate

change because improvements in vineyard

management and winemaking knowledge

have taken place alongside better vintages.

All of these factors cater for today’s

demand for ripe wines that are

approachable earlier. Schultz’s view is

backed by numbers from France, showing,

for example, that the average alcohol level

in Alsace Riesling has risen by 2% in the

past 30 years (and let’s not forget, these are

wines that are also getting sweeter).

According to Smart, viticulture is the

‘canary in the coalmine’ for agriculture.

‘The effects [of climate change] will be

seen earlier, and be more dramatic,’ he

says. Harvest dates are getting earlier in

many regions of Europe, yet grapes are

riper when they are picked. The harvest

in Châteauneuf-du-Pape, for example, is

a month earlier than in 1945. Bernard

Seguin, of INRA, the French agricultural

research institute, reports that for every

1˚C increase in temperature in France, it

is necessary to go 200km north. If the

prediction that temperatures rise by 2ºC

in Europe within 50 years is accurate,

growing conditions are probably going

to change sooner than we think.

The ways in which warming will

affect grape growing are, in many respects,

well understood. Higher levels of carbon

dioxide will increase photosynthesis and

vegetative cycles will shorten. Raised

temperatures will lead to more

evaporation and transpiration, which

could, in turn, lead to vines with water

stress if rainfall levels drop. If winters are

mild, advanced vine growth in the spring

will lead to greater risk of frost or poor

fruit set in some regions, possibly creating

new risks. With the growing season being

earlier, the crucial ripening period of

véraison will fall in the warmer month of

July, instead of August. This will affect

the flavour and aromatic profile of fine

wines. At high temperatures, the aroma

potential of grapes falls away sharply.

Years of practice

Smart notes that the reputations of the

classic regions of Europe were created by

hundreds of years of a climate that was

more or less stable. The well-known

relationship between varieties and climate,

and the consequent strictly delineated

boundaries that mark the world’s historic

wine-growing regions were formed by

centuries of accumulated knowledge and

tradition. The Old World has always had a

headstart in wine: there has always been

the experience of previous generations to

draw on, so fewer mistakes to make. But

the current evidence suggests that the

pace of change for today’s generation in

Europe will be so fast that they will be

the ones to shape the future. Moreover,

they may well be looking to the

experiences of those in the warmer

climates of the New World to know what

the future holds for them in Europe.

‘Vineyards on steep slopes,

such as those of the Mosel

Valley and the Douro, will

suffer most'

The Geisenheim’s Hans Schultz and

Greg Jones of Southern Oregon

University studied climate trends in 27 of

the world’s major wine regions (see

maps, above and over). They found that

between 1950 and 2000, the average

increase in temperature during the vine’s

growing season was 1.3°C. Looking at

the European regions only, the increase

was significantly higher, at 1.7°C. And this is before the heatwave of 2003 and

steady rise in average temperatures since.

‘It’s not just the rise in temperature

that will be the challenge in Europe,’ says

Schultz. ‘For most regions, it’s the

variability that will be the problem.’ The

same study showed increased variability

in climate in 18 of the 27 regions. Schultz

and Jones predict these patterns are set to

continue. Mosel winegrower Ernst

Loosen is all to aware of the issues: ‘We

used to have vintages that were not as

ripe, but we knew what we were dealing

with. Now, it’s a new problem every

year. I want to keep making the same

style of wine, but we have different

problems now.’ He cites the heatwave of

2003 and the botrytis rot problems of

2006. ‘We must learn how to handle

these kinds of vintages,’ he says.

Changes in temperature will, says

Schultz, cause ‘massive fluctuations’ in

rainfall, a scenario that could threaten the

continued viability of some of Europe’s

best vine-growing areas. Shortages of water

are a relatively new problem in Europe,

and one that producers are ill-equipped

to deal with. Quite apart from the legal and

ideological constraints that have prevented

irrigation in the past, there is simply no

infrastructure at present in Europe for

this type of water management. ‘The

New World idea of planning a vineyard

around water availability is a concept

that is absent in traditional wine growing

regions,’ Schultz points out. Vineyards

on steep slopes, such as those of the

Mosel Valley and the Douro, will suffer

most, he predicts, both from the

impracticality of setting up irrigation

systems and from extremes of

precipitation. Heavy rainfall will increase

erosion and degrade the organic matter

in the soil. This is more problematic the

steeper the slope, and will affect how the

soil retains water and the quality of wine.

Adopt, adapt, improve

But it’s not all doom and gloom for the

vineyards. Those that can adapt to the

changing conditions will be best placed

to continue to make fine wine, even if it

is not necessarily the same wine, in the

same place they make it today. Schultz

comments that so far in Europe, we have

only really understood the lower limits of

temperature for viticulture, and have

never explored the upper limits. What is

needed is more understanding of how

existing vine varieties can adapt and still

make quality wine in the areas where

they are planted today. One hopes for

speedier (or more relaxed) legislation to

allow winemakers more flexibility.

For the most part, the French, at least,

seem bullish about their situation. On a

recent week-long trip to the Côte d’Or,

nobody was talking about anything more

sinister than the most recent Burgundy

vintage in the glass before them. And the

Bordelais are relentlessly optimistic.

Bruno Prats, winemaker and former

owner of Cos d’Estournel, says: ‘Yes, there

are problems, but we do have solutions.

Bordeaux has lots of options: there’s

Syrah and Carmenère, and Malbec could

replace Merlot.’ Smart has some words of

comfort, too: ‘It’s not all bad news. Warm

areas like Bordeaux can bring back old

varieties, and hot areas have 20 years to

breed something new.’ Even so, it looks

like his money is still on Tasmania.

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