Misleading framing. The tree emissions are harmless. It’s ordinary fossil fuel pollution that turns them dangerous. Eliminate that and it’s no problem.
Here is the explanation from the article that contradicts its title:
Ozone forms when volatile organic compounds (VOCs) released by some vegetation, vehicles and chemical industries react with nitrogen oxides (NOx), which are emitted mostly by traffic and industry. A series of reactions between these compounds in the presence of sunlight causes ozone to form. Breathing in ozone can inflame or damage the airways, causing breathing difficulties, particularly in people with asthma or lung disease.
Oh noooooo not ozone there’s definitely nothing worse going into the atmosphere than that
It’s not about the atmosphere, it’s about it being at ground level and humans breathing it.
Many trees planted in urban areas — species that are often chosen for their quick growth and climate resilience — are worsening ozone emissions, suggests the study published in Science Advances today
Ozone forms when volatile organic compounds (VOCs) released by some vegetation, vehicles and chemical industries react with nitrogen oxides (NOx), which are emitted mostly by traffic and industry.
Specifically, they mentioned Poplars and Willows. Perhaps more, but I hit the paywall, couldn’t read the whole thing.