The Allergic Response to Climate Change

Allergens reside everywhere and anywhere. They exist within the pollen circulating in the air, on the dust lining furniture, and in the fur of our beloved pets. Very few people are immune to the allergens and their potentially drastic health effects. Some face mild symptoms, such as sneezing, congestion, and tearing eyes, and may not understand the root cause. Others, like me, face a constant battle of harsher symptoms, such as headaches and fatigue. These ailments continue to worsen due to climate change, in which rising temperatures contribute to increased plant growth, humidity, and flooding, all of which increase the prevalence of allergies. The result involves pushing our immune systems into overdrive, further causing other health setbacks. 

Rise of Pollen 

Climate change alters levels of aeroallergens (Singh & Kumar, 2022), including pollen, which affects over 80 million Americans annually, or 23% of our population (“Nothing to Sneeze At,” 2024). Allergic rhinitis, also called hay fever, is commonly associated with pollen allergies. The allergic response stems from the reaction of our immune system. Specifically, when pollen enters the body, our immune system releases antibodies like IgE, which label the pollen as an “intruder.” In the attempt to fight off the foreign material, our bodies release the chemical histamine and produce excessive mucus (Balch, 2024). Severe cases of allergies may interfere with breathing, trigger asthma attacks, and cause infection due to inflammation of the respiratory system. 

Pollen originates from a variety of flowering plants and trees that thrive in warm weather. Spring and summer are often labeled “allergy seasons” due to rapid increases in plant growth. In a study published in Elsevier, two effects of climate change include both an increase in rainfall and the average temperature, which led to higher pollen concentrations for particular plant types (Mousavi et al., 2024). Figure 1 displays findings from the study. 

Figure 1 

Mousavi et al. (2024). Temporal trends of Annual Pollen Integral during the analyzed period. Science Direct. https://www.sciencedirect.com/science/article/pii/S0168192324000637?via%3Dihub

This chart illustrates that most plant species exhibited a significant increase in their annual pollen concentration. The outcomes consist of an extended allergy season as these plants begin an earlier, and thus longer, cycle of pollen production. The resulting allergic response, ranging from congestion to asthma (Singh & Kumar, 2022), signifies the danger associated with this lengthened season. As temperatures, rainfall, and atmospheric conditions fluctuate, the severity of an allergy season is harder to predict. Nevertheless, the data suggest that warmer temperatures drive greater pollen concentrations in the atmosphere, thereby increasing allergy sensitivity. 

Humidity, Flooding, and Mold 

Climate change also alters weather patterns, including lengthening humidity cycles (Climate Change Effects on Mold and Home Prevention Tips, n.d.). Specifically, increased humidity and drastic rainfall stimulate the growth of fungi, many of which thrive in warm, wet environments. Certain types, such as those in the genera Aspergillus, Cladosporium, and Penicillium, can trigger immune responses, including itchy eyes, rhinitis, and an increased risk of asthma (Mold Allergy: Causes, Symptoms, Treatment & Prevention, n.d.). Climate change can elevate home humidity levels to 60% or higher – a dangerous level compared to the acceptable range of 30-50% (Climate Change Effects on Mold and Home Prevention Tips, n.d.). Such readings indicate the importance of closely monitoring the humidity levels within a home environment as weather patterns change. 

The number of floods, and their severity, also continue to increase. They not only damage our property and infrastructure, but also contribute to loss of life, injury, and many health concerns. Rainfall-induced floods and rising sea levels near coastal communities increase the risk of mold in our homes. Such mold often goes undetected and can linger in homes for years. In Tallahassee, Florida, college student Danae Daniels reported “Mold in my closet, my bathroom– literally everywhere” (Charles, 2025), after a natural disaster flooded the region. Like pollen, mold can stimulate mild respiratory irritation, but prolonged exposure poses a risk of more severe, mycotoxin-related ailments. The combination of flooding and humidity creates a perfect storm for mold growth, which can quickly develop within two days (Climate Change Effects on Mold and Home Prevention Tips, n.d.). The cost can mean the loss of homes, money, and belongings, in addition to aggressive immune responses. The impact may be particularly detrimental to those who cannot afford the clean-up process or to move to a new area. 

Figure 2 

Note. Reprinted from Mold grows inside an apartment in Tallahassee, Florida, by J. R. M. Charles, 2025, KFF Health News (URL). Copyright 2025 by KFF Health News. 

The solution is not simply to move away from areas prone to flooding or coastal communities. Instead, as climate change persists, communities must adapt to reduce the impacts of severe storms, temperature shifts, and extreme flooding. This can involve improving home resistance to flooding, using a hygrometer to frequently check humidity levels, and inspecting basements and lower levels for signs of early mold growth. 

Strategy to Address Climate-Driven Allergens  

While the world debates the causes of climate change and the approaches to slow it down, the prevalence of allergens will continue to increase and negatively impact our health. One of the most effective methods of prevention, however, is simply awareness: understanding common allergens and actively avoiding triggers.  

For pollen, this involves identifying which pollen-producing plants are in our environment and understanding when pollen concentrations are high. It also means staying indoors and avoiding strenuous outdoor activities during peak pollen periods. For mold, it means monitoring humidity and conducting cleanups in our living environments to prevent mold growth and lower exposure risk. 

Identifying such allergens early and being aware of individual vulnerabilities is key to reducing long-term or chronic health complications. Asthma, for instance, ranks as a top chronic illness among children (The 9 Most Common Pediatric Chronic Illnesses, 2023). Children with asthma are more susceptible to allergens such as pollen and mold and are at risk of severe reactions that cause respiratory complications and inhibit daily activities. Early testing, such as with a skin prick test, patch test, or IgE antibody test (Allergy Testing: Purpose, Types, Indications & Results, n.d.), helps identify vulnerabilities to specific allergens. As a result, triggers can be eliminated, and conditions like asthma can be better avoided or managed. 

Awareness can also be spread on a larger scale, such as through policy or program development. For instance, implementing a program to provide community testing could help reach members who lack access to allergy clinics or other resources. In addition, the effects of climate change on increased allergen prevalence and immune response can be included within the medical education curriculum. This way, healthcare professionals can educate their patients on prevention and mitigation strategies. With the combination of focused individual and societal action, we can better adapt to our changing climate. 

Liya Taxali is a 2nd year undergraduate at UVA, where she intends to major in Global Public Health. She is on the pre-medical track and hopes to become a pediatric allergist/immunologist due to a personal history of confronting allergies since childhood.

References 

The 9 Most Common Pediatric Chronic Illnesses. (2023, December 6). Link Primary Care. https://linkprimarycare.com/common-pediatric-chronic-illnesses/ 

Allergy Testing: Purpose, Types, Indications & Results. (n.d.). Cleveland Clinic. Retrieved January 1, 2026, from https://my.clevelandclinic.org/health/diagnostics/21495-allergy-testing 

Balch, B. (2024, April 9). Do seasonal allergies seem to be getting worse? Blame climate change. AAMC. https://www.aamc.org/news/do-seasonal-allergies-seem-be-getting-worse-blame-climate-change 

Charles, J. R. (2025, November 17). Mold causes hidden health crisis as extreme weather risk grows. CBS News. https://www.cbsnews.com/news/mold-health-crisis-extreme-weather-flooding/ 

Charles, J. R. (2025). Mold grows inside an apartment in Tallahassee, Florida [Photograph]. KFF Health News. https://www.cbsnews.com/news/mold-health-crisis-extreme-weather-flooding/ 

Climate Change Effects on Mold and Home Prevention Tips. (n.d.). Howard Environmental. https://www.howardenvironmental.com/climate-change-effects-on-mold-and-home-prevention-tips/ 

Mold Allergy: Causes, Symptoms, Treatment & Prevention. (n.d.). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/22309-mold-allergy 

Mousavi, F., Oteros, J., Shahali, Y., & Carinanos, P. (2024, February 26). Impacts of climate change on allergenic pollen production: A systematic review and meta-analysis. Science Direct.  https://www.sciencedirect.com/science/article/pii/S0168192324000637?via%3Dihub 

Nothing to sneeze at: New research shows pollen can change the weather. (2024, May 9). NOAA. https://www.noaa.gov/news/nothing-to-sneeze-at-new-research-shows-pollen-can-change-weather 

Singh, A. B., & Kumar, P. (2022, October 13). Climate change and allergic diseases: An overview. PubMed Central. https://doi.org/10.3389/falgy.2022.964987