By Erin Birgfeld

“Close the windows!” my father’s voice boomed through the house. “Are you trying to kill me? I have hay fever, you know!”

Back from college for the summer, I had opened all the windows to enjoy a mild summer day, so rare in the Washington, DC, area. What I had forgotten was that my father has allergies to all types of pollen. So while I enjoyed the fresh breeze, the open windows also let in those tiny pollen grains that tortured him every year. Sure, my dad could be a little overdramatic— hay fever (the common term for allergies to ragweed and other types of pollen) wasn’t going to kill him. But it does cause his seasonal sneezing, watery eyes, and aggravates his asthma.

My father isn’t the only one avoiding the sweet spring and summer breezes. More than half of Americans have at least one allergy, with hay fever accounting for more than 13 million visits to physicians’ offices and other medical facilities every year. One of the most common environmental allergens is ragweed, which can cause hay fever and trigger asthma attacks, especially in children and the elderly.

And unfortunately, the news for those suffering from ragweed allergies isn’t good. It turns out that climate change can have an effect on pollen and allergy season. Warmer spring temperatures cause some plants to produce pollen earlier and to keep producing later into the fall season. Plus, increased carbon dioxide (CO2) concentrations allow ragweed and other plants to produce more pollen overall. That means more pollen for longer periods of the year! Yikes!

EPA’s Indicators of Climate Change Report features data from the National Allergy Bureau that shows that the length of ragweed pollen season has already expanded by 12-26 days in 8 of the 10 cities where data was collected between 1995 and 2011. Interestingly, ragweed pollen season length increased the most in northern latitudes and less in the south. If this trend continues, people allergic to ragweed pollen will have to deal with bothersome symptoms for longer. That’s nothing to sneeze at.

Dad, what does this mean for you? Since climate change could prolong allergy season for millions of Americans, it’s probably a good thing you moved to Florida…at least for the sake of your hay fever. The climate change impacts on sea level rise and hurricanes is another story, though.

About the author: Erin Birgfeld is the Communications Director for the Climate Change Division within the Office of Air and Radiation. When she’s not working to protect the environment, Erin enjoys hanging out with her two young children, and doing a bit of swimming and biking when she can find the time.