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May 13, 2014

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AAAAI Responds to the Third National Climate Assessment

Climate change can affect every aspect of allergen exposure

MILWAUKEE, WI – The White House released the 839 page Third National Climate Assessment (NCA) last week and experts with the American Academy of Allergy, Asthma & Immunology (AAAAI) believe climate change plays an even bigger role in allergies and asthma than what is being reported.

“If expert predictions are correct, climate change has the potential to affect all aspects of allergen exposure, including both indoor and outdoor allergens, as well as communicable diseases that are related to allergies and asthma,” according to a 2013 AAAAI work group report that was published in the AAAAI’s Journal of Allergy and Clinical Immunology: In Practice.1

The NCA was compiled by the U.S. Global Change Research Program and shed some light on the effect climate change has on respiratory and allergic diseases. Citing a 2008 study that appeared in the AAAAI’s Journal of Allergy and Clinical Immunology (JACI), the authors pointed out that increased CO2 can elevate the production of plant-based allergens.

“For years we have known that higher ambient carbon dioxide concentrations and warmer temperatures will result in increased pollen production2,” said Jeffrey Demain, MD, FAAAAI, Vice Chair of the AAAAI Environmental and Occupational Respiratory Diseases Interest Section. “In northern latitudes especially3, we are recording longer overall growing seasons, earlier starting times and we expect to see more changes to the floristic zones. We are even finding the pollen grains themselves have a more potent allergenic component4.”

More disquieting, though, is how researchers and physicians are able to connect progressive climate changes to increasing rates of allergic sensitization in patients over long periods of time.

“While there are many factors contributing to the rise of allergies and asthma in the past decades, one fact remains: prolonged pollen cycles, more frost free days and higher pollen levels lead to more cases of seasonal allergic rhinitis and more frequent emergency room visits for asthma sufferers,” said Elizabeth Matsui, MD, Chair of the AAAAI Environmental Exposures and Respiratory Health Committee.5,6  

The AAAAI believes the allergist / immunologist sits at the front line of environmental health and must consider the larger implications of changing environmental conditions, including climate change, while adopting the best practices and newest research methods to anticipate the needs of patients.

More information on allergies, pollen, and climate change is available at the AAAAI website.

The AAAAI represents allergists, asthma specialists, clinical immunologists, allied health professionals and others with a special interest in the research and treatment of allergic and immunologic diseases. Established in 1943, the AAAAI has more than 6,800 members in the United States, Canada and 72 other countries. The AAAAI’s Find an Allergist / Immunologist service is a trusted resource to help you find a specialist close to home.


1 Barnes CS, Alexis NE, Bernstein JA, Cohn JR, Demain JG, Horner E, et al. Climate change and our environment: The effect on respiratory and allergic disease. J Allergy Clin Immunol: In Practice 2013; 1(2): 137-41.

2 Ziska L, Gebhard D, Frenz D, Faulkner S, Singer B, Straka J. Cities as harbingers of climate change: Common ragweed, urbanization, and public health. J Allergy Clin Immunol 2003; 111(2): 290-96.

3 Singer BD, Ziska L, Frenz D, Gebhard D, Straka J. Increasing Amb a 1 content in common ragweed (Ambrosia artemisiifolia) pollen as a function of rising atmospheric CO2 concentration. Functional Plant Biology 2005; 32: 667–70.

4 Ziska L, Knowlton K, Rogers C, Dalan D, Tierney N, Elder MA, Filley W, Shropshire J, Ford LB, Hedberg C, Fleetwood P, Hovanky KT, Kavanaugh T, Fulford G, Vrtis RF, Patz JA, Portnoy J, Coates F, Bielory L, Frenz D. Recent warming by latitude associated with increased length of ragweed pollen season in central North America. Proc Natl Acad Sci USA 2011; 108(10):4248-51.

5 Darrow L, Hess J, Rogers C, Tolbert P, Klein M, Sarnat S. Ambient pollen concentrations and emergency department visits for asthma and wheeze. J Allergy Clin Immunol 2010; 130(3): 630-8.

6 Ariano R, Canonica G, Passalacqua G. Possible role of climate changes in variations in pollen seasons and allergic sensitizations during 27 years. Annals of Allergy, Asthma & Immunology 2010; 104(3): 215-22.

Close-up of pine tree branches in Winter Close-up of pine tree branches in Winter