The sneezing, itching, and wheezing linked to hay fever are becoming more severe and widespread—thanks in large part to climate change, according to global experts who say the planet’s shifting climate is fueling an “explosion” of allergies.
The World Meteorological Organization (WMO) reports that warming temperatures and earlier springs are driving longer and more intense pollen seasons. Trees and plants are blooming earlier, flooding the air with pollen for longer stretches of time, while rising carbon dioxide levels boost plant growth and, in turn, pollen production.
“There’s no doubt that climate change is having an effect,” said Nicolas Visez, an aerobiologist from the University of Lille, who noted that different plants react in different ways. While birch trees may struggle with hotter, drier summers, invasive ragweed—known for its high allergenic potential—continues to spread rapidly.
In Europe alone, airborne allergies already affect around one in four adults, and up to 40 percent of children. That number could surge to 50 percent of the population by 2050, the World Health Organization warns.
“We’re in crisis because allergies are exploding,” said Severine Fernandez, president of the French Allergists’ Union. She noted that people who once had mild hay fever are now more likely to develop full-blown asthma within just a couple of years.
Pollution is also compounding the problem. Not only does it irritate airways, but it stresses plants, making their pollen even more potent. “Allergenic and irritant pollen” becomes more common as a result, according to the WMO’s 2023 findings.
In response, countries across Europe are launching local initiatives to better prepare for these new allergy threats. France has created “pollinariums”—gardens that monitor when plants begin releasing pollen. This allows residents to take antihistamines early. In Switzerland, allergy sufferers can now track real-time pollen data through a tie-up between MeteoSwiss and local programs.
Other countries are taking more drastic steps. Japan, for example, began felling cedar trees in 2023 and replacing them with less allergenic species to combat widespread allergy issues.
For those like Simon Barthelemy, an architect near Paris who battles yearly flare-ups triggered by birch trees, the toll is personal. “I’m on antihistamines, but if I don’t take them I get itchy eyes, I’m very tired, I cough… I can’t sleep at night,” he said.
With allergies intensifying and spreading, scientists and policymakers alike are urging better urban planning, species management, and health tracking to brace for what many say is only the beginning.
