Is Climate Change Causing a Year-Round Allergy Season?

If you’re like millions of Americans, your sniffling and sneezing starts in February or March and continues well past the months when the temperature should turn chilly.

Allergy seasons have been lengthening the past few years, making many wonder if allergy season is now a year-round event. Some allergists and experts say that is almost the case and climate change may be to blame.

“Due to climate change we’re seeing warmer temperatures everywhere and, as a result of that, pollen season is starting two, three, four weeks earlier in the spring because of the early thaw,” said Dr. Cliff Bassett, a fellow for the Asthma and Allergy Foundation of America. “In the fall, ragweed season is three to four weeks longer.”

What does climate change have to do with longer allergy season? It all comes down to warmer temperatures creating longer growing seasons. 

“One ragweed plant produces 1 billion pollen grains,”  Bassett said. “The United States Department of Agriculture did some experiments showing ragweed plants can produce three to four times more pollen than usual due to increased carbon dioxide levels.”

Carbon dioxide is the primary greenhouse gas emitted through human activities such as use of electricity, vehicles and heavy industry. Carbon dioxide levels increased 10 percent between 1990 and 2011, according to the Environmental Protection Agency. Higher carbon dioxide levels, essentially, amp up a plant’s production of pollen.

“The pollen itself is even supercharged. It’s more sticky and potent,” Bassett said. “It’s sticking to eyeballs more, which is why you have so much itchiness in your eyes.”

http://www.weather.com/health/climate-change-causing-year-round-allergy-season-20130930