Climate Change Connections: California (Grapes)

Climate change is impacting all regions and sectors of the United States. The State and Regional Climate Change Connections resource highlights climate change connections to culturally, ecologically, or economically important features of each state and territory. The content on this page provides an illustrative example. As climate change will affect each state and territory in diverse ways, this resource only describes a small portion of these risks. For more comprehensive information about regional climate impacts, please visit the Fifth National Climate Assessment and Climate Change Impacts by Sector.

On this page:

• Key Messages
• Introduction
• Climate Impacts
• Taking Action
• Related Resources
• References

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Introduction: California Is a Leading Producer of Grapes and Wine

California is the most agriculturally productive state in the United States, growing almost three-quarters of the country’s fruits and nuts and one-third of the country’s vegetables.¹ California’s top agricultural commodities include milk, almonds, tomatoes, carrots, strawberries, and grapes.¹ Many of these grapes are enjoyed as whole fruit, while others are transformed into juice, raisins, and wine. California is responsible for an estimated 80 percent of wine produced in the United States.²

Grapes and associated industries contribute significantly to California’s economy. In 2022, the grape commodity output was valued at over $5.5 billion.¹ Beyond the direct economic value of grapes and wine, wine-related tourism has economic benefits for the region. The picturesque vineyards of California draw visitors from near and far to drink in both the views and wine. The California wine industry supports hundreds of thousands of jobs and contributes tens of billions of dollars to the economy annually.³

Climate Impacts: Warming Temperatures and Drought Threaten Workers and Grape Production

Every part of the Southwest experienced higher average temperatures between 2000 and 2020, exceeding the long-term average from 1895 to 2020.⁴ As temperatures rise, outdoor workers, including vineyard workers, face more exposure to dangerous heat. In the Southwest, extreme heat is projected to increase, harming worker health and productivity.⁵ Heat-related illnesses can occur when a person is exposed to high temperatures and their body cannot cool itself sufficiently through sweating. Symptoms range from mild swelling, rashes, or cramps to the more serious symptoms associated with heat exhaustion and heat stroke, which can be deadly.⁶ In addition to acute heat impacts, the combination of long-term exposure to heat and dehydration is considered a risk factor for kidney disease. ⁷ Extreme heat can contribute to lost working hours and loss of wages.^{5, 7}

Warming temperatures can also pose risks to many crops, including wine grapes.⁵ For example, warming temperatures are expected to reduce the amount of suitable growing area for wine grapes.⁸ Higher temperatures can also cause grapes to ripen earlier, exposing the fruit to additional heat stress.⁸ Disruptions to the ripening process can affect the chemistry of grapes and impair wine aroma, color, and taste.⁸

Large portions of the Southwest have experienced drought conditions since weekly Drought Monitor records began in 2000.⁴ In California, drought threatens crop production and has resulted in major economic losses—over billions of dollars—across the farming sector.⁵ Drought is a multifaceted problem, requiring complex decision-making as communities work to address water challenges. For example, drought can lead to more water being used for irrigating crops on vineyards, which can reduce streamflow, affect ecosystem function, and contribute to conflicts over water use.⁹

Climate Impacts: Wildfires Threaten Health, Safety, and the Economy

Wildfires can harm property, livelihoods, and human health.¹⁰ Climate change threatens to increase the frequency, extent, and severity of fires because of warmer temperatures and drought.¹⁰ The Southwestern United States has faced an unprecedented number of wildfires in recent years, with California experiencing its seven largest recorded wildfires since 2018.⁵ Wildfires often occur during harvest season, which can be particularly dangerous for agricultural workers who can be exposed to smoke while working outside.⁵

In addition to directly harming people, infrastructure, crops, and ecosystems, wildfire smoke can also negatively affect wine grapes. Ash and smoke can penetrate the skin of grapes in a process known as “smoke taint,” which can undermine the taste of the wine or even ruin it.⁹ Estimates show that smoke taint from the devastating 2020 wildfires contributed to nearly $4.2 billion in losses for the California wine industry.⁵ Expected increases in frequency and extent of wildfires can mean further challenges for California’s wine industry.

Taking Action: Protecting Workers and Safeguarding Agriculture

Addressing climate change requires reducing greenhouse gas emissions while preparing for and protecting against current and future climate impacts. Communities, public officials, and individuals in every part of the United States can continue to explore and implement climate adaptation and mitigation measures. In California, public health leaders, researchers, and farmers are taking steps to address climate impacts in the grape industry, including:

• Protecting outdoor workers. Increasing protections for outdoor workers against the intensifying hazards of extreme heat events and wildfires is important for their safety.¹² The State of California is taking steps to require employers in the agricultural sector to provide adequate shade and water breaks to give workers necessary respite during extreme heat.¹³ Wildfires increase exposure to respiratory hazards for outdoor workers, amplifying the need for improved monitoring and protective equipment.¹⁴
• Growing heat-resilient grape varieties. Vineyards can adapt to climate change by selecting more heat- and drought-resilient grape varieties.⁸ Researchers, vineyards, and wine industry associations are collaborating to identify and share resources about more sustainable growing practices. Market demands for certain types of wines may limit ability to pivot to different grapes.¹⁵ Tools like Cal-Adapt, which provides localized adaptation information for California, can help wine growers understand local challenges and weigh potential adaptation techniques. ¹⁶

To learn more about climate change impacts in California and the Southwest region, see Chapter 28 of the Fifth National Climate Assessment.

Related Resources

• EPA Climate Change Indicators: Wildfires
• EPA Climate Change Indicators: A Closer Look: Temperature and Drought in the Southwest
• EPA Climate Change Indicators: Heat-Related Illnesses
• Fifth National Climate Assessment: Chapter 11: Agriculture, Food Systems, and Rural Communities (U.S. Global Change Research Program)
• California Climate Change Assessment (State of California)
• Climate Action (California Environmental Protection Agency)
• Cal-Adapt (California Energy Commission)
• California State Climate Summary 2022 (NOAA)

References

¹ California Department of Food and Agriculture. (2024). California agricultural production statistics. Retrieved February 20, 2024, from https://www.cdfa.ca.gov/Statistics/

² Wine Institute. (2022). California & US wine production. Retrieved February 20, 2024, from https://wineinstitute.org/our-industry/statistics/california-us-wine-production/

³ Wine Institute & California Association of Winegrape Growers. (2022). Economic impact of California wine. Retrieved February 20, 2024, from https://www.wine-economy.com/

⁴ EPA. (2021). A closer look: Temperature and drought in the Southwest. Retrieved February 20, 2024, from https://www.epa.gov/climate-indicators/southwest

⁵ White, D. D., Elias, E. H., Thomas, K. A., Bradatan, C. E., Brunson, M. W., Chischilly, A. M., Enquist, C. A. F., Fisher, L. R., Froehlich, H. E., Koebele, E. A., Méndez, M., Ostoja, S. M., Steele, C., & Vanos, J. K. (2023). Ch. 28. Southwest. In A. R. Crimmins, C. W. Avery, D. R. Easterling, K. E. Kunkel, B. C. Stewart, & T. K. Maycock (Eds.), Fifth National Climate Assessment. U.S. Global Change Research Program. https://doi.org/10.7930/NCA5.2023.CH28

⁶ EPA. (2016). Climate change indicators: Heat-related illnesses. Retrieved June 11, 2024, from https://www.epa.gov/climate-indicators/heat-related-illnesses

⁷ Hayden, M. H., Schramm, P. J., Beard, C. B., Bell, J. E., Bernstein, A. S., Bieniek-Tobasco, A., Cooley, N., Diuk-Wasser, M., Dorsey, M. K., Ebi, K. L., Ernst, K. C., Gorris, M. E., Howe, P. D., Khan, A. S., Lefthand-Begay, C., Maldonado, J., Saha, S., Shafiei, F., Vaidyanathan, A., & Wilhelmi, O. V. (2023). Ch. 15. Human health. In A. R. Crimmins, C. W. Avery, D. R. Easterling, K. E. Kunkel, B. C. Stewart, & T. K. Maycock (Eds.), Fifth National Climate Assessment. U.S. Global Change Research Program. https://doi.org/10.7930/NCA5.2023.CH15

⁸ Monteverde, C., & De Sales, F. (2020). Impacts of global warming on southern California’s winegrape climate suitability. Advances in Climate Change Research, 11(3), 279–293. https://doi.org/10.1016/j.accre.2020.08.002

⁹ Roehrdanz, P. R., & Hannah, L. (2016). Climate change, California wine, and wildlife habitat. Journal of Wine Economics, 11(1), 69–87. https://doi.org/10.1017/jwe.2014.31

¹⁰ EPA. (2024). Climate change indicators: Wildfires. Retrieved February 20, 2024, from https://www.epa.gov/climate-indicators/climate-change-indicators-wildfires

¹¹ Madhusoodanan, J. (2021). Wildfires pose a burning problem for wines and winemakers. Proceedings of the National Academy of Sciences, 118(34), e2113327118. https://doi.org/10.1073/pnas.2113327118

¹² EPA. (2023). Climate change and the health of workers. Climate change impacts. Retrieved February 22, 2024, from https://www.epa.gov/climateimpacts/climate-change-and-health-workers

¹³ California Department of Industrial Relations. (2020). Heat illness prevention in outdoor places of employment. California Code of Regulations, Title 8, Section 3395. Retrieved February 21, 2024, from https://www.dir.ca.gov/title8/3395.html

¹⁴ California Department of Industrial Relations. (2021). Protecting outdoor workers exposed to smoke from wildfires. Retrieved February 21, 2024, from https://www.dir.ca.gov/dosh/wildfire/worker-protection-from-wildfire-smoke.html

¹⁵ U.S. Department of Agriculture. (n.d.). Climate vulnerabilities of California specialty crops. USDA Climate Hubs. Retrieved February 22, 2024, from https://www.climatehubs.usda.gov/hubs/california/topic/climate-vulnerabilities-california-specialty-crops

¹⁶ Babin, N., Guerrero, J., Rivera, D., & Singh, A. (2022). Vineyard-specific climate projections help growers manage risk and plan adaptation in the Paso Robles AVA. California Agriculture, 75(3–4), 142–150. https://doi.org/10.3733/ca.2021a0019