Lingering Smoke: How Long Will It Last?

Wildfires have become increasingly common due to climate change, which has led to longer and more severe heatwaves during the summer months. These heatwaves, coupled with drier conditions and increased drought, create the perfect environment for wildfires to spread rapidly. The smoke from these fires can have a significant impact on air quality and public health, causing eye and respiratory issues, especially among vulnerable groups such as children and the elderly. With the growing number of people living in wildland areas, it has become crucial to predict and understand smoke dispersion and its potential impact on different regions. Tools like the BlueSky Canada smoke forecast and the ad-hoc smoke modelling tool, Playground, help professionals and the public alike make sense of smoke dispersion and its potential duration.

Climate change's role in wildfires

While wildfires are a natural part of many ecosystems, the changing global climate is amplifying wildland fire activity, particularly in northern and temperate forests. Warmer temperatures, longer summers, reduced precipitation, and drier conditions are all contributing to increased fire activity.

Climate change has been identified as the main cause of increasing fire weather in the American West. As the planet warms, hotter weather, earlier melting of winter snow, warmer nighttime temperatures, and decreasing summer rainfall are all contributing to more destructive fires. The Western U.S., in particular, has seen a significant increase in the amount of land area burned each year, with the largest increases occurring during the spring and summer months.

The risk of wildfires is expected to grow across the United States due to reduced precipitation and higher temperatures caused by climate change. This combination of reduced precipitation and higher temperatures leads to drought conditions, which further increases the risk of wildfires. In addition, the buildup of fuels in some forests due to historical fire suppression efforts can also contribute to more intense fires.

The impact of wildfires can be far-reaching, affecting communities, regions, watersheds, economies, and ecosystems. The released greenhouse gases, such as carbon dioxide, methane, and black carbon, can have long-lasting effects on the environment. The plants that re-colonize burned areas typically remove carbon from the atmosphere, but when fires occur more frequently and consume larger areas, the released greenhouse gases may not be completely removed from the atmosphere if plants cannot grow to maturity before burning again.

To mitigate the risk and impact of wildfires, communities, builders, homeowners, and forest managers can implement various strategies. These include discouraging residential development near fire-prone forests, increasing the space between structures and nearby vegetation, and adopting smart zoning rules. Additionally, addressing climate change through global efforts to reduce greenhouse gas emissions and transition to more sustainable practices can help reduce the frequency and intensity of wildfires in the long term.

Smoke dispersion modelling tools

One such modelling tool is the Sparse Matrix Operator Kernel Emissions (SMOKE) Modeling System. SMOKE is designed to process emissions data and create gridded, speciated, hourly emissions for input into air quality models. It uses a series of matrix calculations to enable rapid and flexible processing of emissions data. SMOKE is supported by the Community Modeling and Analysis System (CMAS) and is distributed by the Center for Environmental Modeling for Policy Development (CEMPD).

Another modelling tool is the FireFamilyPlus, which is used for the analysis of fire danger indices and weather conditions. It assists in predicting tree mortality, fuel consumption, smoke production, and soil heating caused by wildfires or prescribed fires.

The Simple Smoke Screening Tool is a user-friendly online tool that uses a set of basic input parameters such as location, area burned, wind direction, fuel type, and ignition method to plot potential smoke movement. It was developed by the Southern High Resolution Modeling Consortium and is now hosted by the Florida Forest Service.

The BlueSky modelling framework, developed by the USDA Forest Service AirFire team, integrates mapped vegetation datasets, fuel consumption, and emission models with plume rise algorithms to provide information on smoke transport and concentration. This information is used by Air Resource Advisors to create daily forecasts and inform the public about potential risks.

These are just a few examples of smoke dispersion modelling tools that are used to understand and manage the impacts of smoke on air quality and human health. These tools are continuously being improved and updated to advance the field of smoke science and support decision-making in fire management and policy development.

Impacted areas and smoke concentrations

The BlueSky Canada smoke forecast provides estimates of when and where wildfire smoke events may occur in the upcoming two days. The system indicates the areas in Alberta and British Columbia that are likely to be impacted by forest fire smoke, along with the associated smoke concentrations. It is important to note that this forecast is considered experimental due to the uncertainties in fire data, emissions, weather forecasts, and smoke dispersion. The BlueSky Playground tool, for instance, is an ad-hoc, on-demand smoke modelling tool that allows users to create emissions scenarios for prescribed burns and wildfires and then model the dispersion of the resulting smoke.

The impact of smoke from wildfires can extend beyond the immediate vicinity of the fire. In recent years, several states in the Western United States, including California and Oregon, have experienced historic levels of wildfire spread and damage. Consequently, millions of people in these regions have endured extended periods of unhealthy air quality due to wildfire smoke. The growing number of people living in wildland areas further exacerbates the risks to life, property, and public health. Smoke inhalation can lead to eye and respiratory issues, particularly among children and the elderly.

The BlueSky Canada smoke forecast is a valuable resource for professionals and the public alike. It aids in understanding and preparing for potential smoke events. However, it is essential to recognize that the forecast may not precisely align with local smoke concentrations and timing. Therefore, it should be used with caution and in conjunction with other tools and data, such as the Canada-wide forecast, to make informed decisions and mitigate the impacts of smoke on affected communities.

Additionally, it is worth noting that the BlueSky framework does not currently account for smoke from sources outside the forecast domain. As a result, individuals in areas potentially affected by long-range smoke transport are advised to refer to the Canada-wide forecast for a more comprehensive understanding of the smoke's impact on their region. By utilizing all available tools and resources, communities can better prepare for and address the challenges posed by wildland fires and smoke-related issues.

Wildfire smoke and health issues

Wildfire smoke is a complex mixture of particle pollution and other pollutants that can lead to a variety of health issues. The health effects of particle pollution exposure can range from relatively minor issues, such as eye and respiratory tract irritation, to more severe problems, including exacerbation of asthma and heart failure, and even premature death. Even short-term exposure to fine particles over a few days or weeks can increase the risk of these more serious health issues.

Fine particles are respiratory irritants, and exposure to high concentrations can cause persistent coughing, phlegm, wheezing, and difficulty breathing. Even healthy individuals can experience transient reductions in lung function and pulmonary inflammation. Particle pollution may also impair the body's ability to remove inhaled foreign materials, such as viruses and bacteria, from the lungs, making people more susceptible to respiratory infections.

Research has consistently shown associations between wildfire smoke exposure and respiratory health issues, particularly exacerbations of asthma and chronic obstructive pulmonary disease. There is also growing evidence of a link to increased risk of respiratory infections and all-cause mortality. However, more research is needed to clarify the specific causes of mortality associated with wildfire smoke and to determine if certain populations are more vulnerable.

While anyone can get sick from wildfire smoke exposure, some individuals are at a higher risk. Wildfire smoke can have cumulative effects on lung function, especially with continuous exposure over multiple days. Studies have reported a progressive decline in lung function during burn seasons, but more research is needed to understand if this decline persists during off-seasons. The health impacts of wildfire smoke are significant, and with climate change increasing the prevalence and severity of wildfires, it is crucial to address these issues through policies and plans.

Wildfire prevention and management

Wildfires have been raging across Canada and the United States, with smoke from these fires affecting air quality in both countries. While the duration of smoke from wildfires can vary depending on weather conditions and firefighting efforts, there are several measures that can be taken for wildfire prevention and management:

Wildfire Prevention

• Address climate change: Global heating has made wildfires more frequent and intense, so transitioning away from fossil fuels and reducing heat-trapping greenhouse gas emissions are crucial.
• Create contingency plans: Cities and communities, especially those in wildfire-prone areas, should develop contingency plans to protect residents and outdoor workers and designate areas with clean air.
• Pass legislation: Governments can introduce and pass bills like the Wildfire Smoke Emergency Declaration Act and the Smoke and Heat Ready Communities Act to provide resources for affected communities and help them prepare for wildfire smoke and extreme heat.
• Promote public awareness: Educate the public about preventative measures, such as staying indoors, using HEPA filters, and wearing masks when outdoors to reduce exposure to smoke.

Wildfire Management

• Enhance firefighting capabilities: Invest in equipment, field camps, and mobilization activities to support firefighting efforts. Examples include aerial water drops by helicopters and burnout operations to remove unburned vegetation.
• Evacuate residents: In the event of a wildfire, voluntary or mandatory evacuations should be conducted in a safe and orderly manner to ensure the safety of residents and allow first responders uninterrupted access to the fire area.
• Establish designated shelters: Set up shelters in safe locations, such as schools or community centers, to accommodate evacuated residents and provide them with essential resources.
• Utilize technology: Employ satellite imagery and meteorological data to monitor and predict the spread of smoke, helping authorities make informed decisions about potential evacuations and air quality warnings.

By implementing these prevention and management strategies, communities can better prepare for and respond to wildfires, mitigating their impact on residents and the environment.

Frequently asked questions