As one of the premier winemaking regions in the world, the California winemakers of Napa and Sonoma counties are deeply concerned about the impacts of climate change on their vineyards, and ultimately on the quality of wines they produce. As warmer temperatures and wild swings in weather become the norm, every part of winemaking is being scrutinized to find ways to mediate the impact. The soil, water, selection of grapes, timing of the harvest, and even the surrounding ecosystem are all part of this intense effort to continue making world-class wines while simultaneously mitigating the effects of climate change.
In 2019, Jackson Family Wines, based in Sonoma County and Familia Torres, headquartered in Vilafranca del Penedès, Spain, founded International Wineries for Climate Action. The mission of IWCA is to galvanize the global wine community to create climate change mitigation strategies and decarbonize the industry. Eight additional wineries around the world have since joined the effort. Many other wineries in Napa and Sonoma have launched their own mitigation efforts.
The challenges are significant. In July of this year, Napa reached temperatures of 111 degrees Fahrenheit — the highest ever recorded. In 2020, Napa was impacted by the largest wildfire in California history. Even as strategies are implemented to mitigate climate change, intense, record-setting weather events continue to occur.
Responding To Rising Temperatures
The average global surface temperature has been rising for over 100 years. According to Wine Business, 15 of the last 20 growing seasons in California have already been 3 to 5 degrees warmer than the 100-year average. This poses significant challenges to wineries that have been growing grapes intended for cooler climates.
In the past few years, this has resulted in harvesting grapes earlier each year, but this is a temporary fix. Ultimately, the higher temperatures may prohibit the cultivation of certain varietals that are popular in the region.
Larkmead Vineyards in Calistoga has set aside 3 acres of vineyards for a research project focused on testing grape varietals that can withstand higher temperatures. While its current production is focused on cabernet sauvignon, the winery is preparing for future alternatives.
At the University of California Davis, another research project is underway to update the Winkler Index, a measurement developed in the 1940s to determine the best types of wine to grow in a region based on its climate conditions. It’s believed the measure is out of date and needs to account for the significant changes in heat and drought that have occurred in the state. Data will be collected from cabernet sauvignon vineyards throughout the Napa Valley to document conditions in its many microclimates. This information will likely guide future growing decisions for wineries.
While wineries experiment with which varietals to grow in a warming climate, a key strategy for reducing the overall rise in temperatures is the reduction of carbon. A growing coalition of governments around the world has committed to net-zero carbon emissions by 2050. Turning to alternative energy sources, like solar and wind, can help in this effort. Jackson Family Wines recently built a wind turbine in Monterey, California, to generate electricity for both its winery as well as the surrounding community. Ames Morrison, co-founder of Medlock Ames in Sonoma, has converted to solar power for his winery and offices.
Coping With The Impact Of Wildfires
Anyone who lives in, or visits California is familiar with wildfire season, typically in late summer and early fall. In 2017, the Tubbs fire, impacting both Napa and Sonoma, was named the most destructive wildfire in California history. According to CalFire, that record was surpassed in 2020 by the August Complex Fire that burned over 1 million acres.
The immediate concern of wildfire upon wineries is property destruction. But the lesser-known impact is smoke damage to grapes. In August and September of 2020, the LNU Complex Fire roared through Napa, Sonoma, Solano, Yolo, and Lake counties. It’s estimated that the cost of lost wine production was $3.24 billion.
While much of the smoke-tainted grapes went unused, some winemakers used this as a learning opportunity. Andrew Delos, director of winemaking for Far Niente Family of Wineries and Vineyards, said it left many vineyards unharvested. But it also picked grapes for educational purposes. “We wanted to do everything we could to understand impacts and help educate for future vintages,” he said. Jeff Ames of Rudius Wines in Napa didn’t make any red wines. But he ended up picking around 25 percent of the cabernet despite knowing that some or all was ruined. Like Delos, he hoped to learn something.
Dealing With Limited Water
Climate change has resulted in higher temperatures which have impacted water and waterways around the world. With 85 percent of the state currently experiencing extreme drought, access to water for agriculture, including vineyards, is limited.
One of the responses to limited water is dry farming — the cultivation of crops without irrigation. John Hamel of Hamel Family Wines has transitioned all four of his Sonoma Valley estate vineyards to dry farming. This transition can take years as the vines need to learn to adapt to minimal water, pushing their roots deep into the soil. While there’s no exact count of dry-farmed wineries in Napa and Sonoma, many winemakers in the area are trying this approach and with success.
Jackson Family Wines oversees more than 40 wineries around the world, with the highest concentration in Napa and Sonoma. In recognition of the limited water available in the state of California, it has been working to reduce water use in every part of the production of wine. To date, it has reduced usage by 43 percent.
Reducing Harm To Surrounding Ecosystems
Vineyards don’t exist in a vacuum, but are part of a surrounding ecosystem — defined as a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life. Global warming negatively impacts ecosystems which in turn depletes water supplies and harms plant and animal species.
On the other hand, healthy ecosystems can remove carbon from the atmosphere, in turn, slowing climate change. By addressing the health of the local environment — and not just the vineyard — winemakers have come to understand that they can be a part of slowing climate change.
To create a healthier ecosystem and improve biodiversity, Larkmead Vineyards has planted native trees, shrubs, and flowering plants throughout its property. These in turn attract insects, birds, and animals which all contribute to a healthier environment and the protection of watersheds.
Medlock Ames has opted to keep most of its 340 acres of Bell Mountain Ranch wild — just a small portion is planted with vines. The result is a vibrant ecosystem full of native plants, insects, birds, and wildlife that benefit the vineyard through water conservation and improved soil quality.
When a winery plants a new vineyard, it can expect it to last between 25 and 45 years. So winemakers must carefully consider which grape varieties to plant and how they will be impacted by the climate over the next 2–4 decades. If carbon reduction is successful and temperature rise is limited, the types of wines may not vary much from what is being produced today. But this is an expensive gamble, so winemakers continually evaluate all of their options. Simultaneously, they are working to mitigate the impacts of climate change and protect the quality of their wines. This is a long and complicated process, often hindered by continually changing weather. But throughout the Napa and Sonoma region — and around the world — winemakers are committed to finding ways to mitigate climate change while still producing and selling great wine.
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