Urban Heat Island, Contributing Factors, Public Responses and Mitigation Approaches in the Tropical Context of Malaysia

Urban Heat Island (UHI) is a notable thermal phenomenon of any tropical city in relation to increased urbanization. It records a positive urban thermal balance due to higher air temperatures in the densely built areas compared to the rural or sub-urban peripheries under the same climate conditions. The rapid infrastructure development in high-risk areas of tropical cities will be exposing the urban population to extreme heat. As predicted by International Panel on Climate Change (IPCC) climate change scenario, some of the cities in Southeast Asia may be as much as 4 °C warmer by 2050. Being a Southeast Asian country, this would be a consequential threat to the capital cities of Malaysia which suffered inevitable territorial urban development that manifested into formation of severe UHIs with an average gain in surface temperature of 8.47 °C between 1997 and 2013. The increasing surface temperature is mainly associated with the reduction in vegetation cover, open burning, forest fires, land use changes, land clearing, industrial and traffic emissions. Besides, it also exhibits the potential to emerge as one of the public health menace with reduced outdoor thermal comfort levels, heat exhaustions, heat cramps and respiratory ailments among the tropical city dwellers in various urban settings. To overcome this, a number of mitigation approaches such as increase of vegetation cover, replacement of cooling pavement materials and architectural innovations are studied as viable UHI remedies in the context of Malaysia. In addition, target driven assessments are intended to meet the city population’s health needs to assist in designing initiatives to effectively reduce UHI effects. In line with these, this chapter would provide the state-of-art of UHI, known contributing factors and impacts, community needs and other mitigation efforts targeting at urban temperature reductions via case study approaches in the context of Malaysia.