Dhaka is one of the oldest and fastest growing cities in the world. Due to rapid urbanization process, the city is emerging as a mega-city. During the last three decades, the average annual growth has been over seven percent which led to rapid expansion of Dhaka city both horizontally and vertically. (Nahrin, 2008) Urbanization improves our material lives and comfort but brings many devastating consequences such as global warming, environment pollution climatic change and many more. As urbanization and industrialization is increasing day by day, it affects the global environment seriously. Unplanned and haphazard urbanization and industrialization is one the major causes of climate change in urban cities. The greeneries and water bodies are at an alarming state, demolishing with the replacement of concrete surfaces. These emit a significant amount of heat causing the change of urban areas in the energy balance, which induces to a higher temperature than the rural areas. This phenomenon of the rise in superficial heat of urban areas is known as “URBAN HEAT ISLAND” (UHI). Urban heat island affects the microclimate and eventually our health and wellbeing in many ways. Increasing use of motor vehicle, reduction in green spaces, scarce vegetation, the increased amount of built-up areas and much more impact their contribution to the increment in urban heat island. (Anwar, 2016)
It is now a fact that climate change is happening due to the increase in the greenhouse gas such as carbon dioxide, methane etc which acts as a partial blanket for the earth and store the radiation of the solar energy. This has increased the surface temperature of the earth. According to the Intergovernmental panel on climate change (IPCC) the global surface temperature has increased 0.74 ± 0.18 °C during the last 100 years ending in 2005 1. The effect of climate change will be very much severe for the megacities mainly in the Asian megacities of the developing world due to a large number of population concentration. (ref-9).