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Hay fever on the increase due to climate change

The hay fever situation in Switzerland is deteriorating because of climate change: the hay fever season is becoming longer, pollen concentrations are increasing, and highly allergenic invasive plants are becoming widespread. Researchers at the Swiss Commission for Atmospheric Chemistry and Physics (ACP) of the Swiss Academy of Sciences (SCNAT) and the Swiss Federal Office for Meteorology and Climatology (MeteoSwiss) have issued a new fact sheet that summarises the latest findings about the hay fever and pollen situation, and how it is being impacted by climate change.

Hay fever

Although almost nobody in Switzerland suffered from hay fever 100 years ago, it now affects about 20 percent of the population. The hay fever situation is continuing to deteriorate because of climate change. Many plants are releasing their pollen earlier, and with greater intensity. Climate change is also encouraging the spread of invasive and highly allergenic plants such as ragweed.

Air pollution is another factor that probably favours hay fever: it can damage the human respiratory tract, thus promoting asthma and hay fever. Plants stressed by poor air quality also appear to produce pollen that triggers stronger allergic reactions. “To sum up, in the future, people with pollen allergies are likely to be exposed to higher pollen concentrations over longer periods,” the researchers write.

Hay fever is a public health problem

Very large numbers of people in Switzerland are affected – severely, in some cases – and hay fever now costs billions every year. For these reasons, the researchers argue that the public sector should also take steps to address the problem. They propose a series of suitable options for action that include limiting climate change and air pollution, measures to combat invasive species, appropriate public planting in municipalities, and even warning systems. Systems of this sort have recently become possible thanks to new fully automated pollen measurements by the Swiss Federal Office for Meteorology and Climatology (MeteoSwiss). They can help affected individuals to reduce their contact with pollen or take appropriate medication.


  • Allergies


Marcel Falk
Communications and Public Affairs
House of Academies
PO Box
3001 Bern