Urban Ecosystems

, Volume 11, Issue 4, pp 409–422

Estimates of air pollution mitigation with green plants and green roofs using the UFORE model


DOI: 10.1007/s11252-008-0054-y

Cite this article as:
Currie, B.A. & Bass, B. Urban Ecosyst (2008) 11: 409. doi:10.1007/s11252-008-0054-y


The purpose of this study was to investigate the effect of green roofs and green walls on air pollution in urban Toronto. The research looked at the synergistic effects on air pollution mitigation of different combinations of vegetation by manipulating quantities of trees, shrubs, green roofs and green walls in the study area. The effects of these manipulations were simulated with the Urban Forest Effects (UFORE) model developed by the USDA Forest Service Northeastern Regional Station. While UFORE contains several modules, Module—D quantifies the levels of air pollution for contaminants such as NO2, S02, CO, PM10 and ozone as well as hourly pollution removal rates and the economic value of pollutant removal. Six vegetation scenarios were developed within the Toronto study area to compare different subsets of vegetation and their effect on air contaminants. Results of the study indicate that grass on roofs (extensive green roofs) could augment the effect of trees and shrubs in air pollution mitigation, placing shrubs on a roof (intensive green roofs) would have a more significant impact. By extension, a 10–20% increase in the surface area for green roofs on downtown buildings would contribute significantly to the social, financial and environmental health of all citizens.


Green roofAir qualityAir contaminantsTreesShrubsUFORE ModelUrbanPlanningSmart growthBenefitsDensity

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  1. 1.Centre for Social InnovationTorontoCanada
  2. 2.Adaptation and Impacts Research Group (AIRG), Atmospheric and Climate Science Directorate (ACSD)Institute for Environmental Studies University of TorontoTorontoCanada