Climate Crisis Lengthens Pollen Season, Intensifying Hay Fever Misery
A comprehensive new review has revealed that hay fever sufferers are now enduring symptoms for up to two weeks longer than they did during the 1990s, with researchers directly attributing this extended period of misery to the escalating climate crisis. The Lancet Countdown in Europe 2026 report highlights that climate change has "prolonged the pollen season", significantly increasing the duration of allergen exposure for millions of people across the continent.
Shifting Weather Patterns Alter Flowering Seasons
Published in The Lancet Public Health, the report details how shifting weather patterns are fundamentally altering the flowering seasons of plants that release allergenic pollen. Researchers observed an earlier start to the season by one to two weeks for birch, alder, and olive pollen between 2015 and 2024, when compared with the baseline period of 1991 to 2000.
Hay fever, which is an allergic reaction to pollen from trees, grass, and weeds, typically worsens in warm, humid, and windy conditions when pollen counts reach their peak. The traditional season usually spans from late March through September, but climate impacts are now extending this window considerably.
Severe Health Implications for Vulnerable Groups
Anne Biggs, deputy head of clinical services at Allergy UK, underscored the widespread impact of these changes. "Hay fever impacts millions of people in the UK each year," she explained. "While for some their symptoms can be mild, for many their hay fever symptoms significantly impact their quality of life." Biggs emphasized that "research and understanding into the timing and length of the different pollen seasons is vital to support clinicians to ensure treatment and management of allergic conditions can be optimised."
Dr Samantha Walker, director of research and innovation at Asthma and Lung UK, issued a stark warning about the severe health implications. "A longer pollen season will bring more misery for people with hay fever," she stated. "We know from a recent survey that nearly half of people with asthma and more than a quarter of those surveyed with COPD experience symptoms triggered by pollen. If people are allergic to pollen, it can inflame their airways and cause terrifying breathing conditions, which can lead to life-threatening asthma attacks and COPD flare-ups."
Broader Climate Health Risks Across Europe
The findings emerge as a separate allergy strategy, backed by charities, patients, and doctors, points out that the UK has some of the highest allergy rates globally, affecting 39 per cent of children and 30 per cent of adults. This strategy also warns that care and treatment for allergies remain "dramatically under-resourced" within the National Health Service.
Beyond hay fever, the comprehensive report on climate change and health in Europe, compiled by 65 researchers from 46 academic and UN institutions, paints a stark picture of broader health risks. It reveals a dramatic 318 per cent increase in heat health warnings across Europe compared with the 1990s, indicating a significant rise in heat-related health dangers.
The authors estimate approximately 62,000 deaths in Europe were attributable to heat in 2024 alone, with nearly all European regions experiencing increased heat-related mortality between 2015 and 2024 compared to 1991-2000. The report also highlights a concerning surge in mosquito-borne viruses across Europe, with the average risk for dengue outbreaks increasing by 297 per cent between 2015 and 2024 compared with 1981 to 2010.
Urgent Calls for Climate Action and Energy Transition
Professor Joacim Rocklov, from the University of Heidelberg and co-director of the Lancet Countdown Europe, issued a grave warning about the accelerating pace of climate impacts. "Across Europe, the health impacts of climate change are intensifying faster than our response is keeping up," he stated. "Rising heat, worsening household air pollution, exposure to infectious diseases and growing threats to food security are placing millions of people at risk today – not in a distant future."
Rocklov stressed that "the choices we make now will decide whether these health impacts worsen quickly or whether we begin moving toward a safer, fairer and more resilient Europe." The authors further caution that continued reliance on fossil fuels exacerbates these health risks substantially.
Dr Hannah Klauber, from the Lancet Countdown Europe’s working group on economics and finance, commented on the economic dimensions of the crisis. "As the conflict in Iran brings renewed uncertainty and suffering for people across the region, we are again reminded that as long as Europe relies on fossil fuels our economies, our public budgets and ultimately our health will remain vulnerable," she observed.
Klauber concluded with a call to action: "Accelerating the transition to clean, secure energy is not only an environmental necessity, but a vital opportunity to safeguard for people’s wellbeing." The extended pollen season serves as a clear indicator of how climate change is already affecting public health in tangible, measurable ways that require immediate policy responses and adaptation strategies.
