A new study has found that climate breakdown has extended the pollen season in the UK and mainland Europe by between one and two weeks since the 1990s, worsening symptoms for millions of hay fever sufferers. The research, published in the Lancet medical journal, highlights how global heating is altering plant behaviour, leading to earlier and more severe pollen releases.
Researchers analysed pollen data from 1991 to 2024 and found that the seasons for birch, alder and olive trees now start one to two weeks earlier than in the 1990s. In southern parts of the UK, northern France, Germany, and eastern Europe, the seasonal severity of birch and alder pollen has increased by 15-20% since the last report in 2024. The study also warns that invasive species like common ragweed could become a widespread health problem as they expand into new areas.
Joacim Rocklöv, an environmental epidemiologist at the University of Heidelberg and co-director of the report, described the increase in suffering as 'huge,' affecting tens of millions of people. 'It’s one of those everyday indicators that show something is getting a little worse for a lot of people,' he said. The report, compiled by 65 researchers from 46 institutions, also links climate change to rising heat deaths, increased drought, and the spread of infectious diseases like dengue.
The authors emphasise the urgent need for adaptation, including greening cities and shifting subsidies from fossil fuels to clean energy. Annual fossil fuel subsidies in Europe reached €444 billion in 2023 as governments responded to energy price spikes. Despite these challenges, the report notes positive trends, such as a 58% reduction in deaths from transport-related air pollution in the EU between 2000 and 2022, and an 84% drop from electricity generation pollution.
