Climate change has lengthened the pollen season in the United Kingdom and mainland Europe by up to two weeks since the 1990s, according to a new scientific study, worsening allergy symptoms and placing additional pressure on public health.

The analysis shows that pollen seasons have significantly extended in recent decades, increasing irritations such as itchy eyes and runny nose. Although the phenomenon is not as immediately destructive as floods or wildfires, scientists stress that it affects tens of millions of people, creating a substantial overall health burden.

According to The Guardian, environmental epidemiologist Joachim Rocklöv, co-director of the study, highlighted that this is a clear everyday sign of worsening conditions: “It is one of those phenomena that shows something is getting slightly worse for many people. The burden can be very large.”

Higher temperatures and rising carbon dioxide concentrations are increasing pollen production in plants, triggering allergic reactions in people with hay fever. Symptoms range from mild discomfort to severe conditions that can even become life-threatening.

The report, published in the medical journal The Lancet, found that pollen seasons for plants such as birch, alder, and olive now begin one to two weeks earlier in 2015–2024 compared with 1991–2000. At the same time, pollen intensity for the first two species has increased by 15% to 20% in regions such as southern United Kingdom, northern France, Germany, and parts of Eastern Europe.

Researcher Katarina Bastl from the Medical University of Vienna noted that pollen allergies are a direct health risk linked to climate change, adding that the effects of global warming are already visible, though they vary by region.

The Lancet Countdown report, involving 65 scientists from 46 academic and international institutions, tracks 43 indicators related to climate change and health. Researchers found that heat-related deaths increased during the study period by an average of 52 deaths per million people, while daily extreme heat warnings have quadrupled.

In addition, climate stress has contributed to the spread of infectious diseases, with the likelihood of dengue fever transmission more than tripling in recent decades.

The report’s authors emphasize the need for urgent adaptation to a warmer environment, recommending measures such as increasing urban green spaces, issuing health guidance during heatwaves, and redirecting investment from fossil fuels toward clean energy.