Europe to witness climate change triggered ragweed pollen invasion: Study

Driven mainly by the impact of climate change, airborne ragweed pollen concentration is predicted to rise to a much higher level across Europe in coming decades, according to a study published Monday in the Journal Nature Climate Change.

The common ragweed is native to North America but the plant is rapidly spreading as an invasive alien species in Europe. When exposed to ragweed pollen, susceptible individuals can suffer allergic reactions, with symptoms including itchy eyes, sneezing and respiratory distress.

To predict the further spread of ragweed and annual pollen concentrations, researchers from France, UK, Austria and Italy used a modelling approach that takes into account changes in seed dispersal, pollen production, and wind-driven pollen dispersion.

The computer simulations predict that by 2050 airborne ragweed pollen concentrations will be an average of four times higher than current levels, with a range of uncertainty from two to 12 times, depending on seed dispersal rate.

It is estimated that a third of the predicted pollen increase is due to ongoing seed dispersal, and the remaining two thirds is due to climate and land-use changes.

Researchers said this is due to the fact that the rise of CO2 concentrations are the main driving factor for pollen production increase.

Substantial increases in pollen concentration are projected for north-central Europe, northern France and southern UK, areas where pollen loads are virtually zero at present, while pollen concentrations will also increase in many areas already affected, researchers also said.

Any future allergies linked to ragweed pollen would be exacerbated, highlighting the need for the development of effective and regionally coordinated eradication programs, according to the study. Endit