Extreme urban heat poses a significant challenge for Bangkok, impacting the city's residents and economy. The Urban Heat Island (UHI) effect exacerbates this issue by turning developed areas into heat traps, leading to increased mortality, reduced productivity, higher energy consumption, and other adverse effects.
The study aims to provide insight into Bangkok's UHI effect by examining the severity of heat and its locations. Several challenges were highlighted:
Bangkok is experiencing more days and nights with extreme heat. Between 1960 and 2000, the city had 60 to 100 days annually where temperatures exceeded 35°C. Advanced microclimate modeling forecasts that by the end of 2100, under a moderate global emissions scenario, Bangkok could face an additional 153 such days each year.
Heat island intensity varies across districts. Areas like Pathum Wan, Bang Rak, Ratchathewi, and Phaya Thai are on average up to 2.8°C warmer than surrounding rural areas due to high-rise buildings and dense concrete surfaces trapping heat.
There is an increase in heat-related health impacts and premature mortality. Without intervention, a one-degree Celsius rise in temperature could lead to over 2,300 additional heat-related deaths annually. Vulnerable groups at risk include about 880,000 children and one million elderly residents over age 65 who are concentrated in areas facing severe urban heat.
Livelihoods and productivity are also affected. In 2019, around 1.3 million workers in Bangkok spent at least one day per week working outdoors. A one-degree Celsius rise in urban temperatures could result in a productivity drop of up to 3.4 percent, causing over 44 billion baht in wage losses each year.
Infrastructure faces strain as well; a one-degree Celsius increase could lead to an estimated additional cost of 17 billion baht per year for electricity alone. Extreme heat also affects roads requiring extra repairs.
The Bangkok Metropolitan Administration has taken steps like implementing a Heat Action Plan with alerts and greening projects but acknowledges further improvements are needed in coverage and long-term policy commitments.
Short-term interventions such as inclusive heat alerts or opening cooling centers can make an immediate difference. Long-term solutions involve expanding green infrastructure and integrating climate considerations into urban planning.
Addressing urban heat requires sustained governance and collaboration across sectors. Decision-makers might consider creating a dedicated task force to unify efforts across departments and secure funding mechanisms like a dedicated resilience fund for ongoing initiatives against urban heat.