Today, wildfires are among the most catastrophic impacts of climate change, with fires increasing in both frequency and intensity. Many nations have faced increased wildfire activity over recent years, with 2023 being the worst year on record for Canada, as more than 6,000 fires destroyed 15 million hectares of land. Understanding the impact of wildfires and taking action to prevent them is now more important than ever.
Understanding the Spread of Wildfires
At the most basic level, wildfires require three things to start and spread. Heat, fuel, and oxygen (often called the “fire triangle”) are the three critical elements necessary for fire. Heat is required for ignition, whether from natural sources like lightning or human activities. Fuel keeps the fire going, with common examples being dry vegetation and timber. Oxygen is another essential ingredient, with air providing it in abundance.
On a larger scale, the spread of wildfires depends heavily on weather conditions. High temperatures, low humidity, and strong winds provide the perfect conditions for fires to start and spread. Winds are particularly important in large-scale fires, spreading embers to new areas and expanding the wildfire.
Local topography is also key in understanding wildfire behavior. Wildfire tends to spread faster uphill, and other topographical features can influence spread as well. Steep and rugged terrain also complicates firefighting efforts due to limited access, impeding effective containment.
Human activity has a major impact on wildfire ignition and spread. Activities such as campfires or even carelessly tossed cigarette butts can start fires. On a broader scale, land development and forest management both affect the spread of wildfires.
The Role of Wildfires in Nature
Wildfires have existed long before climate change and human activity played any role. Occasional wildfires, typically triggered by lightning, have long been thought to have numerous benefits for local ecosystems. Wildfires can clear away dense canopies, allowing sunlight to reach the forest floor and benefit a wide range of plants there.
Many nutrients and resources locked up in biomass are returned to the soil during a wildfire. This is particularly true of overgrown forests and those with large amounts of dead wood. In fact, some plant species only germinate after experiencing high temperatures that only occur during a wildfire. They take advantage of the conditions after a wildfire to thrive and grow.
The Environmental Impact of Wildfires
While they may play a role in nature, the increasing frequency and severity of wildfires bring about a wide range of adverse environmental impacts. Many of these go far beyond local communities directly affected by the fire, with consequences that extend over long distances and far into the future.
Air Quality
Wildfires create massive amounts of smoke, which can spread over distances as far as thousands of kilometers while maintaining concentrations high enough to impact air quality. There are many air pollutants in wildfire smoke, including ozone, methane, sulfur dioxide, nitrogen dioxide, volatile organic compounds (VOCs), and particulate matter under 2.5 microns in size (PM2.5). These contribute to a wide range of serious health concerns, including reduced lung function, bronchitis, asthma and heart failure, stroke, and premature death.
Soil and Floods
Wildfires have a lasting impact on soil, altering moisture content, structure, and infiltration capacity. This makes the soil more water-repellant, which contributes to flooding. The destruction of the tree canopy also removes natural barriers that typically slow water flow. Surface runoff is a much more serious threat under these conditions, increasing the risk of both erosion and flash floods.
Climate Change
As climate change increases the threat of wildfires, the fires also contribute to climate change. Massive amounts of carbon are sequestered in forests, in both trees and other plants. That carbon is all released to the atmosphere when burned by a wildfire, increasing carbon dioxide concentrations and exacerbating the greenhouse effect. Smoke particles also cause chemical reactions that erode the ozone layer, removing the Earth’s protective shielding and increasing ultraviolet radiation.
Financial Impact
Wildfires also have a major impact on the economy. They can destroy valuable timber and other natural resources. They also severely impact the recreation and tourism industries of areas affected, along with local agricultural production. The direct cost incurred by wildfires can be significant, with the need to replace lost facilities and infrastructure, ensure safe water quality, and restore destroyed habitats.
Quantifying the Extent of Wildfire Air Pollution
Smoke from wildfires affects such a broad area that it can be difficult to quantify and understand in meaningful ways. However, there are programs in place to measure and track wildfire air pollution, providing clearer insights into the extent of the problem and what can be done to mitigate it.
In the US, the National Emissions Inventory (NEI) provides detailed information on a wide range of air pollution sources. That includes NEI report submissions from industry, emissions from various onroad and nonroad sources, and fire sources. This data is compiled and made public every three years. You can browse the latest available NEI data from 2023 through their online data retrieval tool.
Recent studies of wildfire emissions highlight some unsettling trends. The Canadian provinces British Columbia, Alberta, and Quebec all saw record-high wildfire emissions in 2023, with Quebec’s emissions being nearly four times the previous record set in 2013. An estimate from September 20th, 2023, put the year’s cumulative wildfire CO2 emissions at 406 million tonnes across Canada.
Concerted efforts in industry, transportation, and agriculture have led to notable improvements in air quality across the US and Canada. However, some studies have highlighted the regional impact of wildfire in lowering air quality across certain metrics. A study at Colorado State University found increasing PM2.5 concentrations in the Northwest and attributes that increase to wildfire emissions.
Another study supported by the Joint Fire Science Program used global climate model simulations to estimate the impact of wildfire emissions on air quality, visibility, and health. They drew the conclusion that PM2.5 emissions will increase in some regions due to increasing wildfire activity.
Protecting Yourself Against the Impact of Wildfires
Communities directly impacted by wildfires may receive evacuation alerts necessary to protect their lives. Individuals within these communities should follow all instructions to prevent loss of life and to avoid putting firefighters and other first responders in excess danger. If a nearby wildfire may potentially threaten your community, be sure to brush up on evacuation plans and prepare your family for that situation.
A much wider group of people is affected indirectly by the spread of wildfire smoke. While less urgent, this still poses a serious risk of respiratory health complications. Stay up to date on local air quality reports and stay indoors when recommended. In cases of severe wildfire smoke, wearing a respirator may be recommended if you do have to go outdoors. Those with conditions such as asthma, COPD, heart disease, or those who are pregnant should watch carefully for adverse symptoms.
Wildfire Management
Wildfire management consists of a wide range of suppression strategies, tactics, and resources. Understanding the limitations and appropriateness of these tools is essential to developing an effective approach to wildfire management at all levels.
In addition to modern technologies, traditional land management practices also have an important role to play. The use of controlled burns can manage available fuel, removing the accumulation of dead wood before it reaches a critical point. Integrated wildfire management can reduce hazards while preserving ecological values and biodiversity.
Understanding the full ecological impact of wildfires remains a challenge. Modern technology, such as GPS trackers affixed to wildlife, can provide valuable data concerning their behavior in fire-prone areas. However, this approach isn’t always feasible in remote and densely vegetated ecosystems. Insufficient access to high-resolution spatial fire satellite data and limited long-term occurrence monitoring further complicate research.
Measuring the spread and impact of wildfire smoke is also a major undertaking. The use of land-based air pollutant monitoring, satellite-based imagery models, and studies are all essential elements. Data from these sources can improve wildfire management practices. Enhancements in communication, transparency, and data-based decision-making surrounding wildfires help reduce impacts while also promoting public awareness and preparedness.
Addressing the Increasing Challenges Posed by Wildfires
The escalating frequency and intensity of wildfires have a serious impact on the environment and public health. The need for effective strategies to mitigate climate change as it increases the risk of wildfires and the necessity of practical wildfire management practices has never been more apparent.
Collecting accurate data concerning wildfire emissions plays a key role in pursuing these goals. When it comes to climate change and air quality, robust emissions data offers a foundation for regulators to implement effective policies. ERA Environmental is committed to doing its part in providing reliable software for industrial emissions tracking and reporting.
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