MW Topic of the Week -- Climate Change!

So this week we are going to focus on climate change, which heavily effects Paper 1 (viticulture), sort of effects Paper 2 (winemaking), tangentially effects Paper 4 (business) and DEFINITELY effects Paper 5 (contemporary issues, for Stage 2 students only).

In recent years, this topic showed up in 2019, 2018, 2016, and in 2013.

2019: Does a changing climate place greater emphasis on terroir or on choice of grape variety?

2018: Referencing at least three wine regions, discuss how climate change is influencing grape growers’ viticultural practices.

2016: What practical options does a viticulturist have at his or her disposal to address long term changes in climate in an established vineyard?

2013: How important is climate change to the global wine market?

I would take extra care to make sure you know the financial impacts of corrective climate measures.

Looking forward to everyone's thoughts!

Kelli

Sarah Bray

  • I ask these questions to wine makers whenever I can. Old school-ers seem more inclined to make wines styled like the ones they made before it was warmer. Newer wine makers tend to roll with the times. I think an emphasis on terroir or varietal all depends on what side of the pond you are on. I feel like the Old World feels more obligated to lean on terroir, but as the climate changes the fruit will in variably show more.

    To the second part, Sancerre doesn't taste like Sancerre anymore (veggetal, jalapeno/green pepper).  The Sancerre I have tasted recently seems to show the wine makers going with a fruitier style. I was just in Santa Barbara and the wine makers that I talked to said they are trying to show more restraint and are picking earlier, though there are a number of wine makers that go for a fuller/frutier style. And we all know how southern England is getting warm enough to make sparkling in a champagne style.

    3rd part, a grower can always pick sooner in the season. They can also change to later ripening varietals. They can also choose to cellar longer before release to increase complexity and let the fruit soften. All three of these suggestions would cost any grower a LOT of money to do.

    And to the last question. there is no doubt that the single greatest threat to the global wine market is climate change. Climate change isn't just warmer weather. It is wind/ocean currents, droughts/flooding, over-farming, the impart of mass migrations, new fungus, resistant parasites etc.

  • Hello!

    I did this outline earlier this year. Disclaimer: I was a S1 student, and now I know that my examples are basic! I can't just use Torres as an example for all climate change stuff?! ;)

    Climate change is defined as a significant change in the state of the climate that lasts for an extended period of time. The long term climate structure of a region determines the grape growing and winemaking potential of the region. Climate scientists predict that contemporary climate change will continue through the 21st century. This essay will explore how growers in both traditionally warm and cool climate regions are addressing temperature increase, drought, and increased frequency of extreme weather events.

    The earth is warming. Increased growing season heat frequently yields grapes with increased sugar levels and decreased organic acid concentration. However, physiological and flavor maturity do not always sync in seasons with high summer heat events. One solution is to delay the ripening and harvest of the grapes for retention of acidity and maturation of flavors.

    Familia Torres in Penedès is concerned with the impacts on flavor maturation. Miguel Torres says that their key work for the next 20 years is to delay maturation. The company is experimenting with different training systems and canopy management including moving the distance between the cordon and the soil from 60 cm to approximately 90 cm. This in conjunction with modified cover crops has resulted in ripening delay and a greater harmony between physiological and flavor ripeness. Weingut Loosen in the Mosel Valley is also attempting to delay ripening in their warmer sites in order to retain organic acids. To achieve this they are simply hanging a larger crop.

    A longer term adaptation for increased heat is cooler vineyard site selection. Familia Torres has bought land at 4000 ft above sea level in the Pyrenees foothills and land in Patagonia. Both sites are currently too cool for viticulture and have been purchased in anticipation of regional temperature change. Weingut Loosen is also planting in cooler, higher-elevation sites. The higher-elevation sites are designated for their Riesling Kabinett wines which is defined by bright, fresh acidity.

    Climate change includes changes in precipitation patterns. Growers are now faced with droughts and major water shortages. 

    Changes in traditional irrigation strategies are becoming necessary across regions and climate zones. In Mendoza, Bodega Catena Zapata has converted all vineyards from flood to drip irrigation in anticipation of drought. Andes meltwater is an increasingly precious resource and this measure has reduced water use by 75% in two generations of growers. In the Wachau drought has already become an issue, Domäne Wachau has installed an emergency drip irrigation system for drought years and now estimates that two thirds of Wachau vineyards employ this measure. 

    Additionally, growers in many regions are utilizing new rootstocks which have stronger taproots to access water in dry years. Both Willamette Valley Vineyards in Willamette Valley and Roederer in Champagne have implemented these practices in their estate vineyards for Chardonnay and Pinot Noir.

    Growers have also seen an increase in extreme weather events including heat, cold, and summer storms. Stormwater and subsequent humidity management have become crucial for some growers. 

    Summer storm events have increased the humidity and fungal disease pressure in the Mosel Valley. To provide greater resiliency against fungal infection, Weingut Clemens and Rita Busch has intensified the application of biodynamic horsetail teas which they believe increases the vines ability to produce thick berry skins at high temperatures. Additionally, Ridge Vineyards in Cupertino has drilled reverse wells to send stormwater into the aquifer. This minimizes soil erosion and provides buffering for anticipated water shortages due to climate change induced drought.

    In conclusion, climate change is impacting growers across the globe and across climate zones. Growers in both traditionally warm and cool regions have had to adapt to temperature increases, drought, and increased frequency of extreme weather events. Many growers are adapting using short and medium term options including spray, irrigation, crop load, and canopy management changes. Some are utilizing longer term adaptations including planting on drought tolerant rootstocks or planting in cooler sites.

  • 2016: What practical options does a viticulturist have at his or her disposal to address long term changes in climate in an established vineyard?

    A few notes on this off the top of my head.

    • This is a crazy big question. My first thought went to heat and drought management. But extreme weather events like frost and hail need to be discussed too. Established vineyard to me means installs instead of big changes like replanting.
    • Heat: continued vine transpiration provides evaporative cooling. In the event of a heatwave, continued irrigation can be used so that the vine keeps pulling water up and out through the leaves. Growing a larger canopy and removing fewer leaves can help to keep clusters shaded and will keep them cooler. Potential use of overhead sprinklers (but consider drought here too).
    • Drought: drought tolerant rootstocks (read 's awesome article), implementation of drip irrigation where there was none, use of sap flow meters to determine plant water stress so that water resources can be used more efficiently.
    • Frost (specifically spring): late pruning, wind machines (if there is an inversion), smudge pots
    • Hail: hail cannon to break up hail clouds, cloth covers, prayer and insurance 
    • Flood: investing in pumps or other drainage solutions