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!
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.