A major review published in the Lancet medical journal has found that climate breakdown has pushed the start of pollen season in the UK and mainland Europe one to two weeks earlier than in the 1990s, worsening hay fever and allergy symptoms for tens of millions of people. The study, compiled by 65 researchers from 46 institutions, found that the seasonal intensity of pollen from birch and alder trees has risen by 15–20% in parts of the UK, France, Germany, and eastern Europe, as warmer temperatures and higher CO₂ levels cause plants to produce more pollen for longer. Researchers warn that the findings add to a broader pattern of climate-related health harms across Europe, including a 52-per-million rise in heat deaths and a more than tripling of dengue transmission risk, and call for urgent action including redirecting fossil fuel subsidies — which reached a record €444 billion in 2023 — into clean energy.