A smouldering crisis: How Climate Change fuels more frequent and intense wildfires

The global wildfire threat is escalating, with extreme wildfire activity more than doubling worldwide.1 This surge is intrinsically linked to a warming climate, which creates drier forests and alters weather patterns, transforming natural fire events into catastrophic blazes.1 Rising temperatures and prolonged heatwaves desiccate vegetation, making landscapes highly susceptible to ignition.1 Scientists note that increasing Vapor Pressure Deficit (VPD), a measure of air dryness, correlates with higher wildfire risk.2 Furthermore, climate change contributes to severe droughts and altered precipitation patterns, while warmer nighttime temperatures allow fires to burn more intensely and for longer.1

These climatic shifts are demonstrably lengthening fire seasons. Regions like the Western United States and parts of East Africa now experience fire seasons over a month longer than 35 years ago.1 This intensification leads to increased carbon emissions, creating a dangerous feedback loop that further accelerates climate change.1 While climate change is a primary driver, human factors such as historical fire suppression and expansion into wildland areas also contribute to the crisis.1

When the air we breathe turns toxic: The health burden of wildfire smoke

Wildfire smoke, a complex mixture of harmful pollutants, poses a significant human health crisis, capable of traveling vast distances.

What's in wildfire smoke? A cocktail of harmful pollutants

Key pollutants in wildfire smoke include fine particulate matter (PM2.5​), which can penetrate deep into the lungs and bloodstream, carbon monoxide (CO), nitrogen oxides (NOx), and volatile organic compounds (VOCs).3 PM2.5​ is a primary concern due to its ability to cause widespread inflammation and cellular damage.6

The assault on our lungs: Respiratory diseases linked to wildfire smoke

Exposure to wildfire smoke is strongly associated with adverse respiratory outcomes.4 It exacerbates pre-existing conditions like asthma and Chronic Obstructive Pulmonary Disease (COPD), leading to increased symptoms and hospitalizations.3 There's also a growing link to an increased risk of respiratory infections such as bronchitis and pneumonia.4 Studies have shown measurable declines in lung function (e.g., FEV1​, FVC) following smoke events, and emerging research explores potential links to lung cancer, particularly for those with high or long-term exposure like firefighters.3

Beyond the lungs: Wider health impacts and mechanisms of harm

The toxic components of wildfire smoke, especially PM2.5​, can cause systemic effects, contributing to increased all-cause mortality.4 Cardiovascular impacts, including increased risk of mortality and hospitalizations for heart conditions, are a significant concern.8 Mental health can also be affected, with links to anxiety and depression.9 The harm is driven by mechanisms like inflammation, oxidative stress, and immune dysregulation, as pollutants trigger damaging biological responses throughout the body.8

The unequal burn: Wildfires disproportionately affecting vulnerable populations

The health burden of wildfire smoke is not shared equally. Children, with developing respiratory systems, older adults with pre-existing conditions, individuals with chronic respiratory or cardiovascular diseases, and pregnant women are particularly susceptible.3 Socio-economically disadvantaged communities often face higher exposure and have fewer resources to protect themselves, exacerbating health inequities.9 Firefighters and other outdoor workers also face extreme occupational risks.6

Echoes from Africa: Air Pollution, Climate Change, and respiratory health lessons

Many African nations already face severe health burdens from household air pollution (HAP) from biomass fuels and ambient air pollution from traffic and industry.10 Climate change is worsening asthma triggers in Nigeria through dust, heat, and altered rainfall. With fire seasons lengthening in East Africa 1 and many African populations already exposed to wildfire smoke 4, the existing respiratory vulnerabilities could be severely amplified. The health impacts seen from HAP offer a grim preview of potential consequences if wildfire smoke exposure increases without robust monitoring and intervention strategies, which are currently limited in many African regions.10

Clearing the Air: What can be done to protect our lungs and communities?

A multifaceted approach is needed. Individually, staying informed about air quality, reducing outdoor exposure during smoke events, using air purifiers with HEPA filters, and wearing N95 respirators can help.3

Public health strategies include early warning systems, establishing clean air shelters, and ensuring healthcare systems are prepared for smoke-related illnesses.10 Policy and governance measures involve improved forest management (like prescribed burns), stricter emission controls for other pollution sources, and enhanced air quality monitoring.10

Ultimately, the most critical step is addressing climate change by rapidly decarbonizing industries, transitioning to renewable energy, and protecting natural carbon sinks.2

Conclusion

Climate change is undeniably fueling a global wildfire crisis, with toxic smoke posing a severe threat to lung health worldwide.1 The impacts are widespread, from worsening asthma and COPD to increasing respiratory infections.4 Vulnerable populations, including those in African nations already battling air pollution, face disproportionate risks.9

However, these health impacts are largely preventable. Concerted efforts—from individual protective actions to robust public health strategies and decisive global climate action—can mitigate this threat.13 By tackling the root causes of climate change and implementing effective adaptation measures, we can strive for a future where cleaner air and healthier lungs are a reality for all.

References

1. NASA. (2024, May 17). Wildfires and climate change. NASA Science. https://science.nasa.gov/wildfires-and-climate-change/
2. The Nature Conservancy. (n.d.). Yes, climate change is raising the risks—and stakes—of extreme wildfires. https://www.nature.org/en-us/what-we-do/our-priorities/tackle-climate-change/climate-change-stories/extreme-wildfires-are-getting-worse-with-climate-change/
3. The Institute for Functional Medicine. (2023, September 12). Impact of wildfire smoke on respiratory health: Research & interventions. https://www.ifm.org/articles/wildfire-smoke-and-respiratory-health
4. Reid, C. E., Brauer, M., Johnston, F. H., Jerrett, M., Balmes, J. R., & Elliott, C. T. (2016). Critical review of health impacts of wildfire smoke exposure. Environmental Health Perspectives, 124(9), 1334–1343. https://doi.org/10.1289/ehp.1409277
5. Zhang, X., Liu, J., Wu, R., Wang, Y., Yao, X., Chen, J., & Liu, Y. (2024). Wildfire smoke: Health effects, mechanisms, and mitigation. Environmental Science & Technology. https://doi.org/10.1021/acs.est.4c06653
6. Myshko, D. (2023, October 26). Wildfire smoke exposure heightens lung cancer risks and complicates patient outcomes. Pharmacy Times. https://www.pharmacytimes.com/view/wildfire-smoke-exposure-heightens-lung-cancer-risks-and-complicates-patient-outcomes
7. Rice, M. B., Thurston, G. D., Balmes, J. R., Pinkerton, K. E., & Hertz-Picciotto, I. (2024). Wildfire-related air pollution and infectious diseases: Systematic review and future research directions. ACS Environmental Au, 4(5), 263–277. https://doi.org/10.1021/acsenvironau.4c00087
8. Zhang, X., Liu, J., Wu, R., Wang, Y., Yao, X., Chen, J., & Liu, Y. (2024). Wildfire smoke: Health effects, mechanisms, and mitigation. Environmental Science & Technology. https://doi.org/10.1021/acs.est.4c06653
9. Hewage, S. S., Lee, J. J., & Luz, A. C. (2025). Wildfire and smoke risk communication: A systematic literature review from a health equity focus. International Journal of Environmental Research and Public Health, 22(3), 368. https://doi.org/10.3390/ijerph22030368
10. Onyeaghala, C. A., & Obidinma-Igwe, P. (2025). Air pollution and lung health: A significant public health challenge in resource poor countries. The Nigerian Health Journal, 25(1). https://tnhjph.com/index.php/tnhj/article/view/918
11. Amegah, A. K., & Zumla, A. (2024). Household air pollution and respiratory health in Africa: Persistent risk and unchanged health burdens. Journal of Clinical Investigation, 134(18), e179220. https://doi.org/10.1172/JCI179220
12. Edusei, A. K., Van der Gronde, T., Kessels, R., Nsiah-Asare, A., Pelikan, J., & Van Schayck, C. P. (2011). Traffic air pollution and other risk factors for respiratory illness in schoolchildren in Kumasi, Ghana. Journal of Environmental and Public Health, 2011, 804198. https://doi.org/10.1155/2011/804198

The C²REST Project. (2023, September 20). How climate change is worsening asthma triggers in Nigeria. The C²REST Project Blog. https://ccrest.org/news/how-climate-change-is-worsening-asthma-triggers-in-nigeria