Study suggests effects of ragweed increased due to climate change

MILWAUKEE Global climate change is believed to be making ragweed season worse for allergy sufferers, according to report released by the American Academy of Allergy, Asthma and Immunology released Tuesday.

Recent studies suggest that increasing temperatures and carbon dioxide levels are already resulting in longer ragweed seasons and more concentrated pollen counts. The Journal of Allergy and Clinical Immunology has devoted its September issue to exploring the effects of climate change on allergic disease—including ragweed allergy.

That’s not good news for the estimated 36 million Americans who suffer from ragweed allergy, the primary cause of fall allergy symptoms. Ragweed season unofficially begins Aug. 15.

Researchers have decisively linked climate change to “longer pollen seasons, greater exposure and increased disease burden for late summer weeds such as ragweed,” noted Richard Weber, and chairman of the AAAAI Aerobiology Committee, citing among other findings that increased carbon dioxide has resulted in pollen production increases of between 61 percent and 90 percent in some ragweed varieties.

According to data from the AAAAI one ragweed plant can produce 1 billion pollen grains in an average season. Due to the grains’ light weight, they can travel up to 400 miles with the breeze, leaving virtually no outdoor place ragweed-free.