In some ways, climate change is the defining issue of our times. Bleak predictions from scientists have us worrying for the future and suspecting that our progress as a civilisation has been financed by the taking out of an overdraft that we won’t be able to repay. The science? Carbon dioxide is one of a number of greenhouse gases that perform an important role in the atmosphere. They allow solar radiation to warm the planet, and then act as an insulating layer that stops some of this heat escaping. Without the greenhouse effect, surface temperatures on earth would be around 30ºC lower. But human activity has seen atmospheric carbon dioxide levels rise, largely because of the burning of fossil fuels. As a result, the greenhouse effect has become more intense and global average temperatures have risen.
A report from the Intergovernmental Panel on Climate Change (IPCC) shows a clear trend of higher average temperatures, rising sea levels, and increased melting of the polar ice caps. All of these changes occur in tandem with increasing atmospheric greenhouse gas levels. This is all bad news for the wine industry. The world’s great vineyards are carefully sited so that grape variety, soils and climate all work in tandem. Shift the climate, and the quality of the wine will suffer.
Gregory Jones, a scientist from Southern Oregon University in the USA, has examined the implications of climate change for the wine industry. He analysed 50 years of climate data from 27 wine regions and compared them with auction house Sotheby’s 100-point vintage ratings.
He found that growing season temperatures have increased by an average of 2ºC over the past 50 years. Surprisingly, in tandem with this rise in temperatures, the quality of vintages has also improved, although one should remember that winemaking and viticulture have also got better over this period.
Hard to predict
But it’s not just global warming that winemakers are worried about. There has been an increased incidence of exceptional weather events. Previously predictable seasonal patterns have been disturbed; hurricanes and storms are more frequent; droughts are more severe; and there’s an increase in unseasonally warm or cool spells.
One of the biggest worries concerns the Gulf Stream – the warm Atlantic current that ensures that the UK and Atlantic influenced western Europe has a warmer climate than would otherwise enjoy given our northerly latitude. If this were to disappear, some of Europe’s greatest wine regions would be devastated, and there are signs that the flow is already weakening. But should this not be the case, then for some regions a warmer climate, albeit a less predictable one, could represent a huge opportunity. The UK, in particular, could become a serious force in fine wine.
What about the next 50 years? If Jones’s predictions are correct, most wine regions can expect an average increase of 2.04ºC, on top of the 2°C temperature rise seen over the past 50 years. While this may benefit some cooler regions and open up new areas for viticulture, warmer regions could suffer badly. In some cases the careful matching of grape variety to vineyard site may have to be reconsidered. The wine industry, however, is filled with passionate, resourceful and determined people, and so the hope is that growers across the globe will be able to adapt and improvise to continue making great wine – even in the face of a changing climate.
At any times of the recent history of Burgundy (the past two or three centuries), we have seen cycles of colder or warmer periods. The past 15 years have been drier, generally speaking, and it’s now more exceptional to harvest in October than 50 years ago. But again we have seen that many times in the past three centuries.Frédéric Burrier, Château de Beauregard, Mâconnais, Burgundy
We are noticing the effects of global warming. Our rainfall is about 30% down on average, and is forecast to go lower. Being a certified biodynamic farm, we haven’t noticed any water stress yet, but the seasons are getting compressed, timewise.Vanya Cullen, Cullen Wines, Margaret River, Western Australia
In the past three years, the climate has got drier as well as warmer. This vintage, for example, was the earliest start in living memory, and halfway through, we had a record heatwave of 15 consecutive days of +35ºC temperatures – unheard of! The climate does seem to have been all over the place in recent years.Michael Potts, Bleasdale Wines, Langhorne Creek, South Australia
Climate change is significant, with average harvesting dates earlier than before. For the moment, the qualities of the tannins are great, but the problem is the high alcohol we may need to get the ripeness of tannin. It will be a significant problem if we keep on with this tendency.Ricardo Etchats, Telmo Rodriguez, Spain
There is no question that climate change is a significant problem. We have three record rainfall winters in a row, necessitating a belief that change is going to bring erratic weather patterns. In an era of predictable unpredictability, we need to take control of our own destiny.Mike Ratcliffe, Warwick Estate, Stellenbosch, South Africa