Air pollution makes it harder for pollinators to find flowers

Researchers at the University of Reading analyzed 22 studies on how ozone and nitrogen oxides affect pollinators, finding both pollutants break down the floral scent compounds insects rely on to locate food. Ozone alone cut pollinator performance by an average of 42%, nitrogen oxides by 46%, and the two combined by 68% in most experiments, though the combined effect was sometimes smaller because the pollutants partly neutralize each other chemically.

Specialist pollinators tied to a single plant's scent, including some moths, face greater risk than generalist bees, and daytime and nighttime pollinators are exposed to different pollutants depending on when ozone or nitrogen oxide levels peak. Lead author James Ryalls noted ozone levels are projected to keep climbing until around 2050 even as nitrogen oxide emissions fall, and that most research so far comes from Europe, leaving heavily polluted regions like parts of Asia understudied.

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