Urban vegetation facing pollution and over-heating

Abstract

Urban heat islands increase the demand for cooling energy and accelerate the formation of smog. They take place when natural vegetation is replaced by heat-absorbing surfaces such as building roofs and walls, parking lots, and streets. Demand for energy can be reduced and effectively make cooler the urban environment by actions aimed to mitigate the urban heat island. In addition to economic saving, less energy consuming leads to reduce emissions of greenhouse gases as well as ozone (smog) precursors such as NOx and VOCs. Actions taken to lower ambient air temperature can thus significantly reduce ozone and greenhouse gases concentrations in certain areas. Measures to reverse the urban heat island include forest plantation and the widespread use of highly reflective surfaces. Meteorological and air quality models are used to define intervention strategies and planning.