Air pollution affects insect olfaction and thereby pollination

Traffic, heating, industrial fumes, burning of wood and plants generate air pollution. The most important polluting compounds are ozone and nitrogen oxides, such as nitrogen trioxide. Green shift with the purpose of combatting climate change has as an ultimate aim to decrease burning. As a result, air pollution, which causes several million deaths per year worldwide, will decrease. This direct effect on human health is just one of the important benefits associated with decreased air pollution.

A recent study by Chan et al. published in Science (Science 383, 607–611; 9 February 2024) shows how ozone and especially nitrogen trioxide affect the scents of flowers. Flower scents are something that even we humans appreciate, but they are much more important for pollinators, which find their feeding places on the basis of the scents. Enough olfactory molecules can be found even several kilometres from the source for the moths to be able to find the flower patches. Especially nitrogen trioxide oxidizes monoterpenes, which are major scent molecules, with the result that the moths cannot find the flowers.

This finding indicates that when we decrease fossil fuel burning in order to combat climate change, we also improve air quality and help pollination. As a result plant diversity is maintained, and populations of pollinating insects strengthened. One positive thing done can lead to several beneficial side effects.