Climate Change

Climate change is in the news everywhere, stories of doom and cloom surround us. But how will climate change affect the wine industry. In this series we look at the winners and losers of climate change and what the industry is doing to prepare for it.

Climate Change and Wine Overview Climate Change In the 1950’s the biggest concern scientists had for climate change was that the world was cooling down. But in the last 50 years scientists have changed their minds and now the world is experiencing global warming. But why the confusion? It has been known that the climate in the world is related to how much energy the earth receives from the sun. But over decades, centuries and millennia, the amount of energy reaching the earth changes. Whether it be solar spots, or small but subtle changes to the earth’s orbit or wobbles as the earth spins (Milankovitch cycles). It was these that initially concerned scientists that we were due for a big freeze with the growth of glaciers and the polar caps. In actual fact the world is according the Intergovernmental Panel on Climate Change (IPCC) is getting warmer and in the latest statement in 2007, this United Nations body stated that "Most of the observed increase in global-averaged tempertures since the mid 20th century is very likely due to the observed increase in anthropogenic Green House Gas Concentrations." In other words manmade CO2 is very likely the cause of the increase in temperature. With changes in climate now inevitable by at least 1-3.5°C in the next 100 years the question is what will the implications be for the wine industry? The industry will certainly change - wine is the canary in the mine for the agricultural industry, that is wine will feel the influence of climate change well before other agricutural industries. The two biggest influences on a style of wine from a region is climate and grape variety. Grapes are often thought of as secondary but the types of grapes suitable for a region are largely dictated by the local climate. So a change in climate will mean that the wines in a region will change in style and possibly new varieties will be cultivated. This is not true for all grapes, some grapes are more sensitive than other. For example Pinot Noir is very sensitive to climate while its Burgundian stable mate Chardonnay is easy to grown in a wide range of temperatures (the table below shows the temperature ranges of many common grapes). The different effects on style for Chardonnay from the climate are quite noticeable, for example a cool climate Chardonnay such as Chablis is often lean and high in acidity - a very different wine to a hot climate fruit cocktail Chardonnay from Australia. The second picture at the bottom of the page shows the current wine regions of the world with upper and lower grape growing temperture ranges. A key change in climate that will affect wine production is an increase in temperature, particularly in the Northern Hemisphere. This is primarily because the temperature of land heats up much faster than the sea. Also higher tempertures often mean more humidity and likelihood of heavier rainfalls. The total level of rain may not change but when it does rain it will rain heavier for shorter periods of time. The result will mean less water absorbed into the ground and, surprisingly, a decrease in water available in the vineyard. This will be particularly acute in sloping vineyards where the rain runs down the slope and further reduces the available water.

Audio Interviews Interviews are from the UK Wine Show on climate change and wine . "Click to listen" to the interview only. The header will take you to the full show and its notes. Pancho Campo on The Climate Change conference Baceronia 2008 Click to listen Panjo Campo of the Wine Academy of Spain is the organiser of the International Conference on Climate Change and Wine. We caught up with Panjo on the eve of the conference to discuss the key messages.   Greg Jones on Climate Change and Wine 2 Climatology Click to listen Greg Jones is a Professor of Climatology at the University of Oregon in the United States. We talk about the big picture for climate change and what it means for the wine industry. Hans Schultz Climate Change and Wine 3 effects on Grape Click to listen Greg Jones is a Professor of Climatology at the University of Oregon in the United States. We talk about the big picture for climate change and what it means for the wine industry. Richard Smart Climate Change and Wine 4 Click to listen Dr Richard Smart is a world-leading viticulturist and canopy management specialist. We ask how climate change will affect current wine regions. Richard Selley Global Warming and Wine in Britain Click to listen Richard Selley is a Professor of Geology and a Senior Research Fellow at Imperial College, London. He is author of The Winelands of Britain and shares with us his knowledge on climate change in Britain relating to wine.

What will happen to the wines I like?

In the short term very little, remember you are looking at very small changes in the probability of say a drought or a wet summer. For example many people believe the good run of recent vintages in Bordeaux is due to positive effects of climate change. Certainly regions in higher latitudes will over time see a gradual improvement in their wines caused by more reliable vintages. Other regions at low altitude near 30 degrees latitude will find the temperature slowly increases making it more difficult to grow the grape varieties they currently use.

The key trend in the next 5 to 15 years will be in the structure of wine. Warmer temperatures mean lower acidity and higher sugars in the grapes. Sugar converts to alcohol so the end effect is lower acidity in the wine and higher alcohol levels. Acidity gives a wine bite and an edge and often can make a wine feel lighter in the mouth. Alcohol gives fatness to wines and richness, so as the temperature rises wines will feel fuller and heavier in the mouth. While some people prefer full and heavy wines many of the classic styles rely on acidity - this includes New Zealand Sauvignon Blanc, Bordeaux reds and white Burgundies. To preserve the current styles of wines, the easiest thing a producer can do is pick their grapes earlier. As grapes ripen the acidity drops and sugar levels rise. Many Northern European regions are now picking up to a month earlier than 100 years ago.

There is a limit to how early grapes can be picked. If picked too early the grapes will not have enough time to develop flavours and ripen tannins. As a result, eventually regions will need to be replanted. One simple way to minimise the effects of climate is to replant the vineyard not in rows North to South as is currently common, but at an angle. By increasing the angle grapes are planted at, the heating effect on the grapes decreases, slowing ripening. But vineyards could simple choose to replant with other grape varities that are better suited to the change in climate. The table above shows the typical temperature ranges for grapes. Over time you could find that the wines shift about. Will Cabernet Sauvignon be the backbone of Bordeaux in 100 years time or will it give way to Carignanne, Petit Verdot or other varieties?

Changing grapes varieties is one effect climate change will have on wine regions, another is the development of new regions. Already English wines are going from strength to strength as the 'improving' climate makes winemaking more viable. This represents one change as vineyards drift to higher latitudes northward for Northern Hemisphere and southward for Southern Hemisphere. There will also be those who will start growing grapes at higher altitude. The higher a vineyard is, the lower the temperature. New vineyards will open up further and further up hills as producers attempt to get access to cooler zones.

Who controls the carbon rules

Wine is a non essential luxury good that produces 0.1% of man mad Green House Gases. So what should a winery do to manage this? There are a number of important things a winery can do to manage climate change both to mitigate the effects, but also to reduce their own carbon footprint.

In recent times you have seen many wineries becoming carbon zero and following The New Zealand Wine Company makers of New Zealand wines Grove Mill, Sanctuary and Frog Haven. But this piece meal approach has created a problem, the crux of which is that each country is developing its own certification body, with each body able to set a different standard. With a range of different standard the question is, what do you include in deciding your CO2 footprint, where do you stop. Frost protection, fertilisers, harvesting the wine production, bottling many people would agree, but what happens after the wine is made, shipping the wine to the market, moving it to the shop selling the wine. What about the person buying the wine, going to the shop, chilling the wine down and recycling the glass? These could all be taken into account. Then on the flip side, how do you account for the Carbon produced in making the tractor used on the winery in the first place. What is needed is an international body setting the rules!

The problem is who, and how do they get agreements quickly. After all what is green to one person is not green to another. No, the calculations to value a carbon foot print are going down a similar path to Organics. That is where each country or Bloc (as in the EU) decides on what is required to become a standard and if two countries agree to a common minimum standard then the wines can be labelled as such in the country where the wine is purchased. This type of system has many advantages, for example, if a standard is constructed but later needs to be changed perhaps due to more information becoming available, it is easier to get two countries to agree a change in a bilateral contract than an international agreement. It would also be quicker to agree.

There have been a number of standards created. In New Zealand CarboNZero was what The New Zealand wine company used. But since then carbon zero status has been applied to wines in Bordeaux and South Africa, with each country having their own standards. The next step is to create international bilateral agreements that will support and develop brands that the consumer will become aware of. Work is already underway between the New Zealand Australian and Californian governments to come up with the first international bilateral definition of Carbon free.