Allergy Seasons Starting Earlier Due to Climate Change

• Researchers say climate change is causing allergy seasons to start earlier in the spring as well as the summer and fall.
• They say longer allergy seasons create longer periods of allergic reaction and increase medical costs.
• Experts say the best way to lessen allergic reactions is to avoid places where pollen is in the air.

Pollen season is starting earlier and lasting longer thanks to climate change, and experts say it could be problematic for people who have allergies.

Research conducted in Germany and published this week in the journal Frontiers in Allergy found that certain pollen species are beginning their seasons as many as two days earlier each year over a 30-year period.

It’s the latest in a long line of research that suggests pollen season is lengthening, with some studies suggesting pollen season in the United States and Canada has been extended by up to 20 days in the past 30 years.

“The seasons are definitely longer,” Dr. Rita Kachru, an allergy specialist at UCLA Health in California, told Healthline.

“(Spring pollen season) used to start in March, now we’re finding it’s starting in mid-February, and it can go all the way to May. That spring season, which is predominantly tree pollen, often will go even longer. It’ll go to even early June,” she said.

It’s not only spring pollen season that is extending. Kachru says similar trends are being seen at other times of the year.

“Grass season or summer season used to start in May, and now we’re seeing it starting as early as April, and it used to end sometime in August, and we’re seeing it ending early September,” she said. “Fall season, which is predominantly weeds and outdoor mold, used to be predominantly starting in August till late November, and now we’re seeing it start in August but going toward more mid-December.”

Pollen grains are scattered from flowering plants, grass, trees, and weeds.

The allergens then spread through the air, causing problems for those who have allergies.

According to the U.S. Centers for Disease Control and Prevention (CDC), up to 60 million people in the United States experience allergic rhinitis, also referred to as hay fever, every year.

“Climate change will potentially lead to shifts in precipitation patterns, more frost-free days, warmer seasonal air temperatures, and more carbon dioxide (CO₂) in the atmosphere,” the CDC states.

“These changes can affect: when the pollen season starts and ends and how long it lasts each year, how much pollen plants create and how much is in the air, how pollen affects our health (the “allergenicity” of pollen), how much pollen we’re exposed to, and our risk of experiencing allergy symptoms,” the agency adds.