Tree Trouble: When Green Spaces Go Bad Cities have long assumed that urban green spaces are a net positive, providing a respite from the hustle and bustle while reclaiming nature's place in the concrete jungle.
However, new research suggests this assumption may be overly simplistic: some trees can actually worsen air quality in cities. The reality is more complex than commonly acknowledged.
While trees absorb gaseous pollutants, they also emit volatile organic compounds (VOCs) that contribute to ozone pollution at ground level. These VOCs are similar to those found in solvents, paints, and fuel vapors.