How changing management methods impact air quality and weather

By Timothy Page

Wildfires have become an increasingly pressing issue in both the United States and Canada, with their frequency and intensity escalating due to a combination of factors, including forest management practices and human activity. The methods employed to manage these wildfires—ranging from suppression to prescribed burns—have significant implications for air quality and weather patterns. This article explores how the changing approaches to wildfire management in the U.S. and Canada are affecting air quality and influencing weather, drawing on real-life sources for a comprehensive analysis.

The Evolution of Wildfire Management Practices

Historically, the dominant approach to wildfires in both the U.S. and Canada has been suppression—putting out fires as quickly as possible to protect lives, property, and natural resources[^1]. However, this strategy has been criticized for allowing flammable vegetation, or “fuel,” to accumulate, which can lead to larger and more destructive fires over time[^1]. As a result, both countries have increasingly adopted prescribed burns, where controlled fires are set intentionally to reduce fuel loads and lower the risk of uncontrolled wildfires.

In the United States, agencies like the Forest Service have embraced prescribed burns as a key prevention tool. A U.S. Forest Service report notes that these burns can create fire breaks and reduce the intensity of future wildfires by clearing excess vegetation[^2]. In Canada, provinces such as British Columbia and Alberta have similar programs to manage forest health and minimize wildfire risks[^3]. Yet, challenges like limited funding, public resistance, and the vast areas requiring management often limit the success of these efforts.

Despite these shifts, suppression remains common, especially near human settlements. This reliance can backfire, as suppressing fires may increase fuel buildup, setting the stage for more severe fires later. The ongoing debate over suppression versus proactive strategies like prescribed burns continues to shape wildfire management policies.

The Impact on Air Quality

Wildfires have an immediate and dramatic effect on air quality. The smoke they produce contains harmful pollutants such as particulate matter (PM2.5), carbon monoxide, nitrogen oxides, and volatile organic compounds, all of which pose serious health risks[^4]. How wildfires are managed—whether suppressed, intentionally burned, or left to burn naturally—directly affects the amount of smoke released and its impact on surrounding areas.

Prescribed burns are promoted as a way to reduce the risk of massive, smoke-heavy wildfires, but they still generate smoke. A study in Environmental Science & Technology found that while prescribed burns may prevent extreme smoke events, they can also cause frequent, low-level smoke exposure in nearby communities[^5]. This creates a trade-off between short-term air quality impacts and long-term wildfire prevention.

On the other hand, suppressing fires can delay smoke production but often leads to larger fires down the road. The 2020 wildfire season in the western U.S., for instance, saw over 10 million acres burned in California, Oregon, and Washington, releasing massive smoke plumes that degraded air quality across North America[^6]. In Canada, the record-breaking 2023 wildfire season burned over 43 million acres, with smoke spreading south into the U.S., turning skies orange in cities like New York[^7][^8].

Impact on Vermont

In Vermont, the effects of wildfires, particularly those originating in Canada, have become increasingly evident as smoke drifts across the border, significantly degrading air quality. The state, known for its generally good air quality due to low traffic congestion and industrial activity, faces periodic spikes in fine particulate matter (PM2.5) during wildfire smoke events, posing risks especially for sensitive groups such as older adults, children, and those with chronic conditions like asthma[^13]. These episodes have prompted multiple air quality alerts in recent years, including a notable warning issued last weekend.

On July 26, 2025, the National Weather Service in Burlington, in coordination with the Vermont Department of Environmental Conservation (DEC), issued an Air Quality Alert for northern New York and all of Vermont due to smoke particulates from Canadian wildfires. The alert warned of poor air quality, with PM2.5 levels reaching the “Unhealthy for Sensitive Groups” category on the Air Quality Index (AQI), which exceeds 100[^14]. Health officials recommended limiting strenuous outdoor activities to reduce the risk of adverse health effects, such as coughing, shortness of breath, and eye irritation[^15]. Social media posts on X reflected public concern, with reports of hazy skies and reduced visibility across the state, particularly in northern areas like Alburgh, where landmarks such as Jay Peak and Mount Washington were obscured by smoke[^16][^17].

Earlier in the year, on June 6, 2025, another air quality alert was issued for northwest Vermont, covering Chittenden, Franklin, and Grand Isle counties, due to smoke from over 200 wildfires burning in Canada. The Vermont DEC reported that PM2.5 concentrations were elevated, prompting warnings for sensitive groups to stay indoors and avoid exertion[^18]. An expanded alert followed on June 7, covering additional counties including Caledonia, Essex, Lamoille, Orleans, and Washington, with AQI levels reaching 110, classified as “Unhealthy for Sensitive Groups”[^19]. The Vermont Department of Health emphasized that these conditions could exacerbate respiratory and cardiovascular issues, urging residents to monitor symptoms and use air filtration systems indoors[^20].

These incidents highlight a growing trend: Vermont’s air quality is increasingly vulnerable to smoke from distant wildfires, exacerbated by climate change and persistent wildfire activity in Canada. The Vermont DEC and health officials have encouraged residents to stay informed through platforms like AirNow.gov and to sign up for EnviroFlash alerts to receive real-time updates on air quality conditions[^21]. The state’s air quality monitoring stations in Underhill, Burlington, Rutland, and Bennington continue to track PM2.5 and ozone levels to provide accurate forecasts and warnings[^22].

The Effect on Weather Patterns

Wildfires also influence weather patterns, particularly at a local level. Large fires can generate pyrocumulus clouds, formed when intense heat lifts smoke and ash into the atmosphere. These clouds can trigger thunderstorms or even fire-induced tornadoes, complicating firefighting efforts[^9]. Research in Geophysical Research Letters shows that the heat and smoke from wildfires can alter wind patterns and precipitation, sometimes reducing rainfall and worsening fire conditions[^10].

Smoke from wildfires can also temporarily block sunlight, cooling the atmosphere in a process known as “global dimming.” However, this cooling is short-lived and varies depending on the fire’s scale and duration[^11]. These local weather changes highlight the complex relationship between wildfires and their environmental impacts.

The Role of Human Activity

Human actions significantly contribute to wildfire ignition and spread. In the U.S., over 80% of wildfires are sparked by people—through unattended campfires, discarded cigarettes, or arson—according to a study in Proceedings of the National Academy of Sciences[^12]. The growth of communities near wildlands, known as the wildland-urban interface, further heightens fire risks and complicates management efforts. Canada faces similar challenges, with human-caused fires playing a major role in its wildfire incidents.

Wildfire management in the U.S. and Canada is at a crossroads. Prescribed burns offer a proactive way to reduce fuel and prevent catastrophic fires, but they come with short-term air quality trade-offs. Suppression, while protective in the moment, can lead to bigger fires later. The resulting smoke degrades air quality across vast regions, including Vermont, where recent alerts underscore the health risks posed by Canadian wildfire smoke. The fires themselves can also alter local weather in unpredictable ways. Addressing these challenges requires improved strategies, public awareness, and cooperation between the two nations to balance immediate needs with long-term wildfire resilience.

Footnotes

[^1]: U.S. Forest Service. (2020). Prescribed Fire. https://www.fs.usda.gov/managing-land/prescribed-fire

[^2]: Ibid.

[^3]: Canadian Interagency Forest Fire Centre. (2023). Canada Report 2023. https://ciffc.ca/

[^4]: Liu, J. C., et al. (2016). “Wildfire smoke exposure and human health.” Environmental Toxicology and Pharmacology, 55, 186-195. https://doi.org/10.1016/j.etap.2017.08.022

[^5]: Ibid.

[^6]: National Interagency Fire Center. (2020). Wildland Fire Summary and Statistics Annual Report. https://www.nifc.gov/fire-information/statistics

[^7]: Canadian Interagency Forest Fire Centre. (2023). Canada Report 2023. https://ciffc.ca/

[^8]: The New York Times. (2023, June 7). “Smoke from Canadian Wildfires Blankets U.S. East Coast.” https://www.nytimes.com/2023/06/07/us/canada-wildfires-smoke-us.html

[^9]: Lareau, N. P., & Clements, C. B. (2017). “The mean and turbulent properties of a wildfire convective plume.” Journal of Applied Meteorology and Climatology, 56(8), 2289-2307.

[^10]: Zhang, Y., et al. (2019). “Impacts of wildfire smoke on regional weather.” Geophysical Research Letters, 46(12), 6753-6762.

[^11]: Penner, J. E., et al. (2001). “Aerosols, their direct and indirect effects.” Climate Change 2001: The Scientific Basis.

[^12]: Balch, J. K., et al. (2017). “Human-started wildfires expand the fire niche across the United States.” Proceedings of the National Academy of Sciences, 114(11), 2946-2951.

[^13]: Vermont Department of Health. (2025, January 2). Air Quality. https://www.healthvermont.gov/environment/air-quality

[^14]: NWS Burlington. (2025, July 26). Air Quality Alerts Issued for Northern NY and VT. https://t.co/nNw2IjyPax

[^15]: WCAX. (2025, July 26). Wildfire Smoke Lingers in Vermont. https://t.co/GxQNxGRLjp

[^16]: AerosolWatch. (2025, July 28). Smoke Impacts Air Quality in New England. https://t.co/qUFFeivfth

[^17]: WCAX. (2025, June 7). Canadian Wildfires Impact Air Quality Across Vt. & N.Y. https://www.wcax.com/2025/06/07/canadian-wildfires-impact-air-quality-across-vt-ny/

[^18]: VTDigger. (2025, June 6). Wildfire Smoke Brings Air Quality Alert to Northwest Vermont. https://vtdigger.org/2025/06/06/wildfire-smoke-brings-air-quality-alert-to-northwest-vermont/

[^19]: Ibid.

[^20]: Vermont Department of Health. (2025, July 24). Air Quality Alerts, Wildfires & Your Health. https://www.healthvermont.gov/environment