NBS in cities can help regulate air quality by absorbing air pollutants . For example, planting trees or vegetated barriers along streets or in urban forests can reduce particulate matter, the ambient air pollutant with the largest global health burden . However, findings show that trees can also positively affect ground-level ozone , airborne pollen concentrations  and indirectly affect air quality through reduced emissions from energy production offset by shade provision . Certain tree species however can also be detrimental to urban ozone formation by emitting significant amounts of reactive biogenic volatile organic compounds . Decreasing urban emissions of VOCs is an increasingly important ozone mitigation strategy in urban areas .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report