Link to the article in Gradient's Trends Spring 2023 newsletter.

Recurring wildfires in the Napa and Sonoma Counties of California have created a set of niche problems for the surrounding wineries, on top of the widespread air quality and public health impacts of these fires.

California’s wine-producing regions of Napa and Sonoma have seen more than their fair share of wildfires over the last several years. For example, in 2017, the Atlas Fire (50,000 acres), Nuns Fire (44,000 acres), and Tubbs Fire (36,000 acres) caused extensive damage. In 2018, the County Fire burned 90,000 acres across Napa and Yolo Counties, and in 2019, the Kincade Fire burned over 77,000 acres in Sonoma. In 2020, these catastrophic wildfire events continued, with the Glass Fire covering 67,000 acres in Napa and Sonoma, and the LNU Lightning Complex Fire consuming over 350,000 acres across five counties, including Napa and Sonoma. The above examples offer some perspective regarding the scope and scale of wildfires in Napa and Sonoma Counties, and set the stage for reflections on widespread impacts to air quality caused by wildfires.  In particular, we can see how winegrowers and wineries have dealt with smoke taint – the absorption of smoke-related pollutants, such as volatile phenols, by grapes, and the resulting undesirable impacts to the taste and smell of wines – as well as the measures taken by state and local governments to establish certain wildfire protection standards for development in high fire hazard severity zones.

The air quality and public health impacts of wildfire smoke are often overshadowed by broader wildfire risk mitigation strategies.  That is, huge efforts are made, of course, to contain and control wildfires and to protect life and property, with subsequent attention focused on recovery and mitigation.  Yet, the potential for adverse health effects on people, living both near and far from the air quality impacts of a particular fire, can be significant, including issues related to exposure to particulate matter (PM), carbon monoxide, and other air pollutants.  Indeed, in the US EPA’s strategic plan for 2022-2026, it identified wildfire smoke pollution as a climate change vulnerability that could affect the agency’s ability to meet national air quality goals. In that context, for example, there will likely be ongoing tension between the need and/or desire for prescribed burns in areas that are not in compliance with National Ambient Air Quality Standards (NAAQS). Federal and state agencies will need to continue to discuss these issues with an eye toward ways to communicate wildfire smoke impacts to the public in a timely and effective manner.

Along with the obvious challenges to life and property, winegrowers and wineries face the specific issues of smoke taint and the harvest and production of smoke-affected grapes. Smoke taint may result in a total or partial loss of a particular vineyard, and attendant claims to insurers for coverage. Some winemakers have become especially adept at producing around smoke taint, but the winemaking process can be very challenging with no guarantees for success. That is, different measures, such as activated carbon or reverse osmosis, might be used to address smoke impacts, but overall wine quality may still be impacted and the very stigma from knowledge of the fires may be difficult to overcome. From an insurance protection perspective, winegrowers have some options with respect to fire preparedness and subsequent mitigation and response (see Farella Braun + Martel’s Fire Preparedness for Vineyards and Wineries here).

With respect to wildfire protection standards for development, the State of California issued State Minimum Fire Safe Regulations that went into effect on April 1, 2023 (see Farella Braun + Martel’s article on State Minimum Fire Safe Regulations here). These regulations provide for such things as minimum road access standards for fire response and evacuations, measures to preserve undeveloped ridgelines, creation of water supply reserves for emergency fire response, and strict vegetative management. As well as the simple exercise of “due care” (i.e., the principle that one may owe a duty of care to employees, visitors, and neighbors to address and/or mitigate known and potentially dangerous situations) in the context of property ownership and operation, these regulations will impact the siting and expansion of vineyards, wineries, and hospitality areas, as well as short- and long-term residential development.

While this past winter brought great news throughout California with the end or near-end of many years of drought (for most of the state) due to a steady influx of atmospheric river systems, that same rain has promoted vegetation growth that will create ample opportunity for more wildfires and their profound impacts. As winegrowers grapple with preparing for wildfires and dealing with these impacts, we can only hope that wine will continue to nurture the soul and play some small role in getting all of us through the next set of wildfire challenges.