Increased urbanisation in metropolitan cities has given rise to what is termed the heat island effect. With vast tracts of open land being covered by buildings, roads, pavements, parking lots and other hardscape there is a quantum increase in ambient temperature due to heat reflecting off these surfaces and slowing down of wind speed. Hard surfaces also ensure that ground water recharge is next to zero, thus exacerbating the water crisis. A case in point is Mumbai where a difference of 13⁰C in temperature was recorded between dense congested suburbs like Ghatkopar (33⁰C) and the relatively more green areas like Powai (20⁰C). Heat islands like Ghatkopar are complex urban phenomena, destructive microclimate zones within megacities. An analysis of 14 cities in 13 countries has established that heat trapping infrastructure such as concrete roads, asphalt, poor vegetation cover, air pollution, stubble burning, garbage incineration etc amplify the difference in temperature between urban sprawls and rural areas. The simple act of planting trees will provide shade and heat insulation which will also have a direct impact on energy consumption. But we are busy cutting down trees for 'development' and 'progress'.
