Climate Change and Wine – A Sobering Reality

Wildfire. Drought. Searing heat. Sudden cold. Relentless rain. Fierce hail and winds. Swarms of insects destroying crops. Sounds like something out of a bible story, right? Unfortunately, it’s reality for the world’s wine growing community.

Climate change is a reality and the wine industry is a ‘canary in the coal mine’ according to Gary Pickering, a Professor and Research Scientist at Brock Cool Climate Oenology School in Ontario. The world is getting warmer. The past four years have been the hottest on record for planet Earth. The effects of changing temperature are playing havoc with weather and if there is any crop that suffers the vagrancies of unpredictable climatic conditions, it’s grape growing. And, these effects are increasing in frequency and magnitude, says Pickering.

How Weather Affects Grapes

The grapes used in wine production, Vitis Vinifera, can be one of the ficklest crops a farmer could choose. It can’t be too hot as grapes will reach sugar levels that create burning alcohol levels before flavours can develop. It can’t be too cool as grapes won’t ripen properly and will make wines that are thin, flavourless, and acidic. Uneven growing conditions can alter sugar and tannin levels that will affect a wine’s character. And not usually for the better.

Early frosts can damage flower buds, reduce yields, and cause uneven ripening. Rain at harvest can dilute juice and the result is wines that are watery. Hail mid-season can destroy crops and have wiped out the production of entire regions. Searing heat causes vines to ‘shut down’ and not focus any energy on producing grapes at all. Changes in climate can allow conditions for normally unseen pests or diseases to prosper and negatively affect grapes, resulting in the requirement for spraying, chemical use, and its accompanying increase in costs to the farmer. These costs are ultimately downloaded onto the consumer and make wine more expensive.

Perfect Growing Conditions

There is a relatively narrow range for successfully growing and ripening vinifera grapes. Between 30–50 degrees latitude both north and south. The warmer areas are quickly becoming too hot to allow a sufficiently long enough growing season – before sugar levels get too high and grapes can’t develop the phenolic ripeness that develops flavours and structure.

Cooler regions are also becoming too hot for the grape varieties previously selected for the climate. Grape growers are having to make serious changes in the vineyard to accommodate the fluctuations in temperature and growing conditions.

Warmer Weather Changing Varieties Planted

Greg Jones, a Professor of Wine Education and Environmental Studies at the Linfield College in McMinnville, Oregon, notes that the 16 cool climate regions in the world have witnessed a 2.52 degree increase in average temperature since measurements started to be recorded consistently in the late 1800s. It doesn’t sound like a big change, but even the smallest incremental change has dramatic effects on farming. Jones points out that it takes years to establish a vineyard and many more before vines are mature and offering fruit at their peak in terms of balance between yield and quality. It takes three years in the ground before the fruit is even worth considering for a low-quality commercial wine and up to decades more to really see the vines hitting their stride and producing ‘world class’ products. Planting a vineyard is now requiring a crystal ball to predict varieties that will not only tolerate the climate today, but also the one anticipated in the future. Vineyards are being planted to avoid the most solar radiation (facing NE in the northern hemisphere and SW in the southern) and existing vineyards are being re-orientated, with the direction of rows reconsidered to reduce exposure to sunshine. Locations that were thought too cool for grape growing are getting planted and famous hotter areas are being abandoned.

Changing Techniques in Hot Zones

Hotter zones suffering from drought are seeing ‘dry farming’ techniques introduced to reduce the stress on irrigation water supplies. Drought resistant varieties are being created and are replacing traditional grapes in some areas. Vine canopies are being allowed to grow bigger to shade grapes from the hot sun. This creates humid conditions for damaging mould and mildew and can cause challenges for harvest, both hand and mechanical.

Industry buyers need to accept the fact that some varieties, which were unsuited for a particular growing region may now be perfect. Be aware that some of your favourite hot climate regions are going to produce wines that are burning with searing alcohol and have flabby, unbalanced profiles. Storied vineyards may have to re-evaluate the varieties that dominate their vineyards and growers will have to be open to planting in what are historically unsuitable regions.

No longer will we be able to count on centuries old perceptions and reputations. The savvy buyer will cast out preconceived notions and start selecting wines using their palates and support growers that are innovating to keep producing the best wines their regions and changing climates will allow.

Tim Ellison is a Certified Chef de Cuisine and Sommelier with approaching half a century of experience in the hospitality industry. He currently serves as Director of Operations at the Pacific Institute of Culinary Arts.

Photo courtesy of Jonathan Ford.