What Happens During a Wildfire?

Wildfires can be deadly and disruptive. Learn more about what happens during a wildfire, including how it can affect everything from wildlife to infrastructure.

Wildfires can be caused by a variety of factors, including lightning strikes, campfires, cigarettes, and even car accidents. Once a fire starts, it can spread quickly due to factors such as weather, high winds, and dry conditions.¹

When lightning strikes a tree or other vegetation, it can ignite a fire that can quickly spread to nearby trees and brush.¹ Human-caused wildfires from activities such as campfires, cigarettes, debris burning, and operating equipment make up nearly 90% of wildfires in the United States.  In dry conditions, vegetation becomes extremely flammable, and fires spread quickly. High winds can also fan the flames and cause the fire to spread even further.²

How Do Wildfires Affect Humans?

Wildfires can cause property damage and displacement, forcing people to evacuate their homes and find temporary shelter which can be stressful and disruptive.⁸ It takes days or even weeks before people can return to their homes after a wildfire.¹³  In 2020, wildfires in the western United States cost insurers up to $13 billion. The previous average cost was $7 billion.¹⁴

Furthermore, wildfire smoke irritates the lungs and causes respiratory problems, especially for people with asthma or other lung conditions.3 Air pollution caused by wildfire smoke is linked to behavior changes, such as spending less time outdoors which leads to a more sedentary lifestyle. People who experience these changes are more likely to develop psychological distress or social isolation.⁴

How Do Wildfires Affect Wildlife?

Wildfires can have a devastating impact on the water supply for animals and marine life. The heat from the fire can cause streams and rivers to dry up, leaving animals without a source of vital water. The ash and debris from the fire can also contaminate water sources, making them unsafe for animals to drink. The influx of toxins can poison animals that drink from or hunt in the affected water source. The greatest impact of water pollution is felt by fish, aquatic and riparian plants, and marine mammals.⁹

The destruction of habitats caused by wildfires can lead to the displacement and death of many animals. In 2020 nearly 17 million animals died due to the Pantanal fires in Brazil, this fire burned 11 million acres.¹⁵ Animals that are unable to escape the fire are put in life-threatening situations. These animals are at risk of being caught in the fire path or suffering from smoke inhalation. The loss of vegetation following a wildfire can also lead to a decrease in food sources for the animals that survived. In addition, the loss of vegetation can lead to soil erosion and flooding, which can further harm wildlife.¹⁰

How Do Wildfires Affect Air Quality?

The smoke from wildfires contains a variety of harmful particles and chemicals, including carbon monoxide, nitrogen oxides, and volatile organic compounds. Inhaling wildfire smoke causes inflammation in the body, posing a significant risk for people with underlying health conditions.¹¹ Wildfire smoke can also reduce visibility and create hazardous driving conditions, increasing the risk of accidents. You do not need to live near a wildfire to experience these adverse effects. Smoke and particulate can travel thousands of miles.⁵ Therefore, it is important to prepare for wildfire smoke no matter where you are located. Keep wildfire smoke out of the house by using a portable Air Cleaner, consider a high-efficiency HVAC filter, or wear an N95 respirator mask.⁵

How Can Wildfires Affect Infrastructure?

Furthermore, wildfires can damage roads, bridges, and other infrastructure, making it difficult for people to travel and access essential services. The loss of power and communication lines can disrupt services and make it difficult for people to communicate during an emergency.¹²

Too much sediment, or dirt, from wildfires, can cause flooding in reservoirs when they are already full. This can impact infrastructure management strategies. Utility companies are dealing with excessive sediments and pollutants that end up in their water system. Additionally, wildfires could physically damage infrastructure components such as melting underground water pipes and tainting water with chemicals, rendering water unsafe to drink.⁶ In some instances wildfires cause significant damage to bridges by burning the undergrowth beneath them causing unsafe structural integrity. Such a scenario would impact the structural integrity of the bridge.⁷