Impact of Climate Change Scenarios on Indoor Comfort and Cooling Energy Consumption in Urban Heat Island Residential Areas

In Taiwan, the birth rate is declining annually, and by 2024, a quarter of the cities will be super-aged societies. With the highly dense development of urban areas, many cities have experienced the urban heat island phenomenon. In addition, climate change has led to rising temperatures in various regions in recent years. However, there has been a lack of research exploring the potential hazards and impacts on the health and well-being of the elderly resulting from these two phenomena. Due to the limited number of monitoring stations established by the Central Weather Administration, and the fact that some of these stations are located in higher altitude areas, the measured data are unable to clearly depict the extent and intensity of urban heat island phenomena. Additionally, future climate data will need to be simulated using global atmospheric models and scenario of global warming. This study analyzed the differences in indoor thermal comfort and annual cooling energy consumption by using high-resolution simulated climate data to assess the effects of the urban heat island phenomenon, and evaluated the impact of global warming scenario.

The National Science and Technology Center for Disaster Reduction (NCDR) adopted the high-resolution global atmospheric models developed by the Geophysical Fluid Dynamics Laboratory (GFDL) at Princeton University to conduct global climate estimation simulations under the RCP8.5 warming scenario. Subsequently, the data was downscaled to a 5-kilometer resolution for the Taiwan region using the Weather Research and Forecasting (WRF) model. The simulation periods included the baseline period (1995-2014) and a 2°C temperature increase scenario under RCP8.5 (2034-2053). This study focused on the densely developed built-up areas of Taipei City and New Taipei City as the research area, comprising a total of 38 delineated zones. EnergyPlus was employed to simulate indoor temperatures and cooling energy consumption for aggregated residential households across these different zones. The results showed that during the baseline period, the urban heat island center areas had an average indoor temperature 0.4 degrees Celsius higher and an average annual cooling energy consumption 320 kWh/year higher compared to surrounding areas in summer. Furthermore, under the global warming scenario, the indoor temperatures became more severe. The urban heat island phenomenon not only leads to increased indoor temperatures in residential buildings but also exacerbates health risks and economic burdens for the elderly due to climate change. The results can serve as a reference for local governments in developing climate adaptation strategies.

Keywords: Global Warming Scenario, Urban Heat Island, Health Risk for the Elderly, Indoor Comfort, Cooling Energy Consumption