For further information on Urban Heat Island Effect

http://eetd.lbl.gov/HeatIsland/PUBS/PAINTING/

http://eetd.lbl.gov/HeatIsland/Vegetation/Evapotranspiration.html

http://www.urbanheatislands.com/toronto

http://www.epa.gov/heatisland

Urban heat island effect

Urban Heat Island Effect (UHI) occurs in metropolitan areas with a high percentage of dark, impermeable surface area and a lack of green space. These surfaces absorb and trap heat from the sun, causing a rise in daytime temperatures and preventing nighttime temperatures from decreasing. This creates an overall rise in urban temperatures, sometimes up to 10°C hotter than surrounding rural areas.

UHI is primarily caused by land surface modification and lack of vegetation, and secondarily by energy usage (cars, industry, residential, etc). An additional factor is the energy used to cool homes and businesses affected by UHI, which may temporarily relieve the excess heat, but ultimately contributes to the overall rise in temperature by increasing energy consumption.

There has been an estimated 16,200 square kilometre increase in Toronto’s UHI zones from 1985-2004.