How electric vehicles could help pollinators find flowers again

A hidden threat is making it harder for bees, butterflies and other pollinators to do their job: air pollution is scrambling the floral scents they use to find flowers. Colleagues and I have just published research showing that ground-level ozone and nitrogen oxides (two pollutants strongly linked to fossil fuel use) significantly impair pollinators’ ability to locate and feed from flowers. The good news? The global shift away from fossil fuels, including the rise of electric vehicles, could eventually ease this pressure. But timing matters. Things may get worse before they get better. Flowers release complex cocktails of volatile organic compounds, essentially their perfume, to attract pollinators. These scents act like a GPS for bees and other insects. But when ozone and nitrogen oxides (NOx) react with these compounds, they break down or alter the chemical signals. The result is that pollinators struggle to find the flowers they need. This isn’t just a problem for wild plants. Almonds, apples, oilseed rape, strawberries and many other important crops depend on insect pollination. When pollinators can’t forage efficiently, yields and quality can suffer. What the evidence shows We analysed 22 experimental studies, mostly from Europe, that tested how elevated levels of ozone and NOx affect pollinators’ ability to find and feed from flowers, as well as their overall abundance. On average across the studies, elevated ozone reduced pollinator performance by 42%, while NOx reduced it by 46%. When the two pollutants occurred together (as they do in the real world), the average reduction was 68%. However, only a small number of studies tested the pollutants both separately and in combination. In those comparisons, the additional impact of combining the two pollutants was relatively modest. Pollinators’ searching efficiency – the ability to locate flowers – was hit hardest, dropping by 67% on average. Feeding efficiency and overall abundance were less affected. This suggests the main problem with the pollution is that it disrupts pollinators’ ability to find flowers, rather than being directly toxic to the insects themselves. The coming ozone peak – and why it happens There is a complication, however. NOx and ground-level ozone are linked chemically, so cutting NOx emissions will not necessarily reduce ozone immediately. In fact, under a middle-of-the-road emissions scenario, global low-level ozone levels are projected to keep rising until around 2050, even as NOx emissions begin to fall. This is partly because ozone and NOx interact in the atmosphere. NOx can react with and destroy ozone. When NOx levels are high, as they often are near roads or in cities, this “quenching” effect helps keep ozone concentrations down. So, as we cut NOx emissions from diesel vehicles and other sources, this quenching effect weakens. With less NOx around to break it down, ozone concentrations can actually climb. Other ozone-forming pollutants, such as methane, also remain high for longer in this scenario. Only after this mid-century peak do sustained reductions in NOx and other precursors drive ozone levels down again. Under this middle-of-the-road scenario, ozone is projected to fall back below present-day levels after 2050. Faster decarbonisation would bring that recovery sooner. Why diesel emissions matter Diesel vehicles, especially heavy-duty trucks and agricultural machinery, are among the largest sources of NOx emissions. In many regions, heavy-duty diesel vehicles alone account for more than 70% of on-road NOx. These emissions not only directly harm pollinators. Through their effects on ozone, they also alter the chemical environment around flowers. Bad news for bees. Ivan Rwatschew / Alamy Electric vehicles produce zero tailpipe NOx. Replacing diesel vehicles with electric alternatives, particularly in freight, construction and farming, would cut an important source of NOx and, over time, help reduce the ozone pollution that interferes with floral scents. The benefits would be even greater as electricity generation becomes cleaner. Our analysis shows that the rate of pollinator recovery will depend heavily on how quickly we reduce these emissions. Delaying the phase-out of diesel vehicles would prolong the mid-century ozone peak and delay the ecological recovery we all need. Conceptual model illustrating how nitrogen oxides and ozone concentrations before 2050 degrade floral odours, impairing pollinator foraging success. After 2050, declining ozone precursors due to sustainable energy transitions are expected to facilitate long-term recovery. Created in BioRender. Ryalls, J. (2026) EVs for bees, CC BY What needs to happen now Protecting pollinators should be considered a co-benefit of clean air and climate policy. Accelerating the transition from diesel to zero-emission vehicles, especially in heavy-duty and agricultural sectors where diesel remains important, would reduce a major source of NOx. We also need better monitoring and research. Our evidence mostly comes from European studies on bees and a few other pollinator groups. We urgently need more research in high-pollution, biodiversity-rich regions, and on a wider range of pollinators including moths, flies and beetles. The timing and location of pollution reductions could also matter. Measures that reduce exposure during peak flowering, for example, could help limit the disruption to pollinators before longer-term reductions in ozone kick in. The fossil fuel transition is not just about carbon and climate. It is also about restoring the chemical cues that pollinators depend on as they search for flowers. If we move quickly enough, we can shorten the difficult mid-century period and give bees, butterflies and the crops they support a genuine chance to recover. The science is clear: cleaner air means healthier pollinators and more resilient food systems. Electric vehicles are one powerful tool in that toolkit. The sooner we deploy them at scale, the better the outlook for the insects that help feed us all.