2024 Western megafires

The Jasper wildfire is one of three record-breaking megafires in North America—along with the 2024 California wildfires and the 2024 Oregon wildfires — where blazes intensified at an alarming rate. According to a July 2024 Inside Climate News, these three wildfires in Western North America are fueled by climate change, creating a "unique...cocktail of conditions". Concerns have been raised about the potential for megafires—also referred to as mega-fires and mega fires—by firefighters since at least 2018, raising questions about wildfire management.

Background of the disaster

The Western Megafires of 2024 refers to a collective of large scale wildfires spanning from Western Canada to the Southwestern United States (US) during the aforementioned calendar year. While universally undefined at present, the term ‘Megafire’ has historically been used to describe fires of an increasingly unprecedented size and destructive nature. With one recently proposed and conservative definition, being those fires of >10,000 ha in size, encompassing single, or multiple yet related ignition events. Using even this conservative definition, many of the 2024 wildfires in the west may still be classified as megafires. Several of the most remarkable, by way of overall destruction, loss of life, or otherwise unique devastation include:

Jasper Wildfire (Jasper, Alberta, Canada) – July 22, 2024

Following a night of lightning strikes and fueled by strong winds, the Jasper Wildfire quickly grew to an estimated 32,722 ha in size. Quickly prompting the total evacuation of the city of Jasper (pop. 4,817 (2023)). During its subsequent progression, approximately 30% of the total structures of the town were destroyed , and one death of a firefighter was recorded while fighting the blaze. To help rebuild, the government of Alberta has approved initial disaster recovery funding of 149 million CAD.

Park Fire (Butte & Tehama, California) – July 24, 2024

The largest of 7,473 California wildland fires in 2024, and a cumulative 173,854 ha burned across multiple counties. With arson credited as the initial precipitant, the blaze went on to destroy over 700 structures, and rank as the fourth largest wildfire in US history. Fire suppression costs alone are estimated at 310 million USD. The total financial toll being, as of yet, unquantified.

Durkee Fire (Baker & Malheur, Oregon) – July 17, 2024

Amidst the largest wildfire season in the state’s history emerged the Durkee Wildfire. Ignited by a lightning strike, the Durkee fire ravaged an estimated 119,084 ha before eventual containment. The fire destroyed several buildings (2), but remained largely restricted to less densely populated areas. However, extensive smoke produced by the blaze prompted the American Lung Association to release public service announcements warning of “extreme harm” due to air quality in the region.  

A recently published analysis of over 60,000 wildfires from 2001 to 2020 in the continuous US revealed that average peak daily growth rates of fires has more than doubled in the Western US over the past 2 decades. This data suggests that moving forward, larger and more aggressive wildfires, including mega-fires, will become ever more the norm. Leading US experts in environmental research advise this increase is driven by climate change, and has led to concern over implications for public health, socioeconomics, and environmental protections. Specifically, the defense of ecosystems, health and social stability, and air quality.

Geographical and Physical Impact

1. Geography and ecosystem impacts

• Vegetation and soil degradation

Wildfires severely damage vegetation cover, leading to soil exposure and degradation. High-intensity fires, in particular, disrupt the soil structure and create a hydrophobic layer, which prevents water infiltration and increases the risk of surface run-off and erosion, further impacting vegetation recovery and consequently post-fire debris flow susceptibility.In the Jasper area, fires have altered the forest structure, reduced space for fire-resistant species, and increased ecosystem instability.

• Hydrological changes and pollution

After wildfires, ash and burnt organic matter enter water bodies and increase the concentration of elements such as nitrogen and phosphorus, thereby triggering eutrophication and promoting excessive algal growth. Such pollution poses a threat to water supply systems and aquatic ecosystems

2. Physical and social impacts

• Human displacement

Hundreds of thousands of people have been displaced by the destruction of residential areas by wildfires. In 2023, 232,000 people were evacuated due to wildfires in Canada. In 2024, the ‘Park Fire’ in California was the fourth largest wildfire in the state's history, destroying 709 structures and causing severe damage to communities, including Cohasset. At the same time, the fires prompted massive evacuations, particularly in Kern County and other affected areas.

• Social inequality

Wildfire disasters disproportionately disrupt the lives of the most vulnerable socio-economic groups and are as much a product of the ecological environment as they are of the social environment. Socially marginalised communities are particularly vulnerable to wildfires because they disproportionately lack the resources needed to prepare for and recover from wildfires and are often underrepresented in wildfire planning processes.

3. Air quality and health impacts

• Smoke propagation

Smoke from wildfires can impair air quality by increasing concentrations of particulate matter (PM), ozone, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and other hazardous air pollutants, with well-described effects on respiratory disease and all-cause mortality.

4. Climate impact

• The catalytic role of climate change

Increased droughts, high temperatures and extended fire seasons due to climate change are making fires more frequent and severe. At the same time, the burning of forests is releasing large amounts of carbon sequestered by forests into the atmosphere, which may further affect climate change. In the case of the wildfires in Jasper National Park, for example, due to the potential impact of climate change on the area of forest burned in North America, Amiro et al. (2009) used the Canadian Global Circulation Model (CGCM1) to predict that the amount of greenhouse gases emitted as a result of wildfires in Canada would double by the end of the 21st century. Similarly, data from the California mega-fires in the US in 2020 show that the carbon dioxide produced by the wildfires (9,100 tonnes) has far exceeded the state's annual carbon dioxide emissions from electricity production by about 3,000 tonnes more.

Local and international response - Risk mitigation and mega fires response

The 2024 Western mega-fires prompted an unprecedented response at local, national, and international levels, underscoring the increasing complexity and challenges of managing such disasters.

Local and national responses

In the United States, given the increased risks that wildfires were posing to the country, legislative initiatives like the Emergency Wildfire and Public Safety Act were proposed to enhance forest management and community preparedness in California. This act seeks to reduce wildfire risks through active land management, including prescribed burns and vegetation thinning, while also fostering markets for biomass utilisation. However, the act has faced criticism from environmental groups, who warn that reduced oversight could lead to exploitative logging practices that may not effectively mitigate fire risks.

State-level responses in fire-prone regions like Oregon highlighted the growing financial pressures associated with wildfire management. In 2024 alone, Oregon spent $250 million on wildfire response, more than double the allocated budget. This shortfall prompted calls for a sustainable funding structure to address the increasing frequency and intensity of wildfires.

Canada faced its own set of challenges, particularly in the aftermath of the Jasper wildfire, which devastated parts of the Canadian Rocky Mountains World Heritage Site. The government deployed a multi-faceted response, offering financial relief for evacuees, disaster assistance for affected Indigenous communities, and rent relief totalling $15.2 million for businesses in Jasper National Park. Reconstruction efforts emphasised fire resilience, with new policies mandating fire-resistant building materials and zoning reforms to facilitate recovery.

International cooperation responses and proposals

At the global level, the United Nations Environment Programme (UNEP) and other organisations have been emphasising in the recent years the critical role of climate change in exacerbating wildfire behaviour. Recommendations included integrating fire management across national policies, improving wildfire monitoring systems, and fostering international collaboration to share fire behaviour data. Emphasis was placed on "living with fire" strategies, which advocate for risk-informed urban planning, evacuation route design, and ecosystem-based adaptation measures.

Risk mitigation and adaptation

Experts warn that reactive firefighting strategies alone are insufficient to address the growing prevalence of megafires. Researchers argue for expanded use of prescribed burns, despite their inherent risks, to manage wildfire fuels and reduce fire intensity. Integrated wildfire management, encompassing prevention, readiness, response, and recovery, has been identified as a key strategy for adapting to escalating wildfire risks.

However, climate change remains a dominant driver of megafire behaviour, with rising temperatures and prolonged droughts creating conditions conducive to fast-spreading and large-scale wildfires. In the Western United States, fire growth rates have increased nearly 400% over the past two decades. The rapid expansion of the wildland-urban interface (WUI) further exacerbates risks, as urban encroachment into fire-prone areas increases exposure to wildfires.

Policymakers are urged to adopt proactive measures that combine land management reforms, climate change mitigation, and community education. UNEP (2022) states that effective collaboration between scientists and decision-makers is essential to create adaptive policies and avoid the "firefighting trap"—a cycle of escalating suppression costs without addressing root causes.

Short and long term health consequences

The 2024 western mega-fires had profound health implications, both short-term and long-term, for the affected populations. These health consequences stemmed primarily from smoke exposure, physical injuries, and psychological distress. Over time, mega-fires also exacerbated vulnerabilities in public health systems, particularly in the context of already fragile healthcare infrastructure in rural and underserved areas.

1. Short-term Health Impacts

The wildfires generated massive amounts of smoke containing hazardous pollutants such as particulate matter (PM2.5), carbon monoxide, and volatile organic compounds (VOCs) . Acute exposure to these substances caused respiratory symptoms, including exacerbations of asthma and chronic obstructive pulmonary disease (COPD), increased hospital admissions for cardiovascular events, and heightened mortality rates in vulnerable groups, such as the elderly, children, and individuals with preexisting conditions. As daily wildfire PM 2.5 concentrations increased, high blood pressure and "all-cause" heart outcomes increased both on the day of exposure and two days after exposure . According to studies, wildfire smoke exposure can increase all-cause mortality by up to 12% during periods of extreme pollution .

The physical consequences of burns and injuries from the fires themselves were also significant. Emergency responders and residents faced risks of direct harm, including thermal injuries, during evacuation efforts. For example, in the case of the Jasper Wildfire in Alberta, Canada, one firefighter tragically lost their life, and several others sustained injuries .

2. Long-Term Health Impacts

The psychological toll of the fires was immense. Evacuation, loss of homes, and displacement led to widespread anxiety, major depressive disorder (MDD), and post-traumatic stress disorder (PTSD) . Studies on previous wildfires have shown that affected populations can experience long-term mental health impacts. The one-year estimates of post-disaster PTSD rates among different risk groups were mainly reflected in direct victims (30%-40%), rescuers (10%-20%), and general population(5%-10%) . Children, adolescents, firefighters, and evacuees were particularly vulnerable, as the disruption to their routines and education compounded stress and anxiety levels .

Over the long term, wildfires can contaminate soil and land environments, water, and indoor environments. Specifically, high concentrations of environmentally persistent free radicals were found in charcoal samples that remained stable for at least five years after the fire. Wildfires increase the mobility and bioavailability of heavy metals, leading to contamination of nearby water bodies and potential health risks through accumulation in aquatic ecosystems and human consumption . House dust retains limited amounts of heavy metals and PAHs 1–2 years after wildfires, highlighting the need for further research on persistent chemicals and their long-term health impacts .

Long-term exposure to wildfires, particularly within 50 kilometers over the past decade, has been associated with a slightly increased risk of lung cancer (4.9%) and brain tumors (10%), providing initial epidemiological evidence of these health impacts .

Also, reproductive health concerns emerged, as studies on wildfire smoke exposure during pregnancy have indicated potential adverse outcomes, including preterm births and low birth weights . Foo, D. et al. (2024) showed the research data that during pregnancy, every 5μg/m increase in wildfire smoke-related PM 2.5 exposure was associated with a 0.78% increased risk of death in children under 5 years of age (95% CI, 0.17% to 1.39%) .

Lessons learned from the disaster

Previous western mega-fire events have shaped responses and preparedness to reduce health impacts and strengthen community resilience in the events of 2024.

Insufficient Emergency Communication

Many residents during the 2018 California Camp Fire did not receive timely warnings because of outdated or fragmented alert systems. Long-term respiratory issues were reported due to prolonged smoke exposure, in addition to increased hospitalisations for cardiovascular events, as discussed in section . Local governments implemented integrated alert systems like Wireless Emergency Alerts (WEA), combined with targeted notifications via text, email, social media, and apps like Nixle and CodeRED. Investments in better forecasting and alert systems can reduce prolonged exposure.

Delayed Air Quality Monitoring

During wildfire events, air quality data was often delayed or unavailable in real-time, leaving residents unaware of the health risks. In the 2017 California Tubbs Fire, poor air quality extended for hundreds of miles, affecting urban populations far from the fire site. The Environmental Protection Agency's AirNow platform was enhanced with real-time data, and low-cost air quality sensors were deployed to rural and underserved areas. Timely, accurate air quality data is essential for informed decision-making during wildfire events.

Inaccessible Air Quality Resources

During the 2017 and 2018 wildfire seasons, many residents in smoke-affected areas lacked access to N95 masks or clean air spaces, particularly in rural or low-income communities. Since the introduction of the Clean Air Spaces Act 2023, cities like Portland and San Francisco now distribute free N95 masks and set up "clean air centers" in libraries and community centers during wildfire events. Equity must be a priority in emergency resource distribution to ensure vulnerable populations are protected.

Strained Healthcare Systems

During the 2021 Dixie Fire, local hospitals were overwhelmed by patients with respiratory and cardiovascular issues, highlighting a lack of preparedness for surges. To mitigate this, healthcare systems in fire-prone areas have a focus on implementing surge capacity plans, stockpiling medical supplies and ensuring staff training on wildfire-related conditions. Disaster preparedness must extend to healthcare systems to manage increased demand.

Underestimated Mental Health Impacts

Initial disaster response efforts after events like the Camp Fire focused primarily on physical recovery (e.g., rebuilding homes) while neglecting mental health support. As discussed in section 4, people affected by megafire events can experience long-term mental health impacts. After the 2018 California Camp Fire, survivors reported high rates of PTSD, anxiety, and depression, underscoring the need for accessible mental health services post-disaster. States now allocate funding for long-term mental health programs, including mobile counseling units and community support groups. After the 2021 Colorado Boulder County Fire, the importance of long-term counseling and community support programs was recognised for displaced families. Recovery must address both physical and psychological impacts for holistic community resilience.

Despite efforts to learn from previous disasters, current mitigation measures struggle to keep pace with the escalating scale of mega fires. 9 of the top 10 largest wildfires in California history have occurred in the last decade despite significant investments in new technology and equipment. There remains a need for continued investment in wildfire mitigation, equitable resource distribution, and climate adaptation policies to address both immediate and long-term challenges.