Pacific Southwest Research Station

Pacific Southwest Research Station
800 Buchanan Street
West Annex Building
Albany, CA 94710-0011

(510) 559-6300

Urban Ecosystems and Social Dynamics

Urban Ecosystems and Processes

AIR

Emissions of carbon dioxide from power plants and other sources contribute to climate change. Motor vehicles are a primary source of other air pollutants that can threaten human health and environmental quality. Urban forests improve air quality by reducing atmospheric carbon dioxide levels and absorbing air pollutants. Trees can directly sequester carbon dioxide as woody and foliar biomass while they grow. By shading buildings and streets, trees reduce energy used for heating and air conditioning, thereby lowering emissions from power plants. Properly planted and managed trees can also reduce the level of particulates, ozone and other pollutants in the atmosphere. Consult the references below for additional information on how trees influence air quality.

Featured Study

Effects of Tree Cover on Parking Lot Microclimate and Evaporative Hydrocarbon Emissions from Parked Vehicles - This study shows that trees provide important benefits in parking lots by moderating the heat absorbed by asphalt. Cooler air temperatures reduce ozone concentrations by lowering hydrocarbon emissions. The cooler the car, the lower the rates of evaporation from gas tanks, hoses, and vehicle fabrics. Trees in Davis, California parking lots reduced surface asphalt temperatures by as much as 36°F, vehicle cabin temperatures by over 47°F, and fuel-tank temperatures by nearly 7°F. This study was a cooperation between California Air Resources Board, University of California Cooperative Extension, Albertson's, Inc., and USDA Crop Pathology.

References

• Read the featured study summary and see the publications and products from the study.
• See our other studies about AIR.
• View all products and publications on this topic.