By Abbas Nazil
Scientists are warning that rising air pollution is disrupting the chemical communication between flowers and pollinators, threatening global food production and biodiversity.
Research has shown that pollinators such as bees and moths rely heavily on the airborne aromas released by flowers to locate nectar, sometimes detecting scents from as far as a kilometer away.
However, human-driven pollution, including ground-level ozone and nitrogen oxides, degrades these volatile organic compounds, altering or masking floral scents.
This makes it harder for insects to recognize and find their target plants.
Experiments led by ecologist Robbie Girling at the University of Reading revealed that bees exposed to ozone-altered floral scents often failed to recognize them.
Other studies found that air pollution can change the chemical makeup of flowers, with lavender taking on sour notes and eucalyptus adopting orchid-like aromas, creating confusion for pollinators dependent on specific signals for survival.
A 2024 meta-analysis of 120 studies across 19 countries showed that ozone reduced the performance of beneficial invertebrates by 31% and nitrogen oxides by 24%.
With three-quarters of leading food crops relying on animal pollination, researchers warn that declining pollinator efficiency could reduce agricultural yields and food security.
Field studies further confirm the impact, showing that black mustard plots exposed to ozone had 37% fewer pollinators, while flowers exposed to both ozone and diesel pollution attracted almost half as many pollinators as control sites.
Nocturnal insects, such as hawkmoths, are also at risk as nitrogen oxide radicals degrade nighttime floral scents, reducing plant fitness and pollination rates.
Scientists are exploring potential solutions, including training pollinators to recognize degraded scents, a method similar to traditional bee training techniques used in agriculture.
Some experiments have shown promise, with insects learning to respond to altered aromas when paired with sucrose rewards.
Other strategies include breeding plants with stronger scents or diversifying farmland with more pollinator-friendly flowers.
Experts stress that while pollution is not the sole driver of global pollinator decline, it adds significant stress to already fragile populations, compounding threats from pesticides, habitat loss, diseases, and climate change.
With pollinator numbers already in sharp decline across Europe and North America, researchers argue that reducing air pollution remains one of the most effective ways to safeguard ecosystems and global food production.
