Climate Change Impact on The Urban Heat Island Effect Based on Shared Socioeconomic Pathway Scenarios: a Study Case of Busan City

Abstract This research uses Shared Socioeconomic Pathway (SSP) scenarios to examine how climate change affects the urban heat island (UHI) effect in Busan City, South Korea. Urban areas consistently experience higher temperatures than rural ones, a trend worsened by climate change and urbanization. This study assesses regional and temporal temperature patterns using a comprehensive analysis of temperature data from thirteen urban and six rural weather stations (2010–2014), as well as a projection (2015–2054) of a future model under different SSP Scenarios. The concept uses quantile mapping as a statistical downscaling technique to improve global climate model outputs from coarse resolution (0.25°) to fine-scale urban applications (0.01°). The findings demonstrate that whereas urban regions continuously have warmer temperatures than rural ones, the intensity of the UHI varies over time and depending on the situation. There are also noticeable seasonal asymmetries, such as notable winter warming and exceptional summer cooling. According to previous studies, eastern Busan has historically experienced higher temperatures than adjacent rural areas, and this pattern is expected to intensify under both SSP scenarios, particularly SSP585. Interestingly, while winter warming significantly increases (by up to 5–7°C) by 2050, summer temperatures decrease by 3–5°C, as compared to usual temperatures. Although there is a consistent urban temperature excess, linear regression and correlation analysis reveal a substantial link between urban and rural temperature trends. The significant connection between urban and rural temperature variations suggests that while large-scale climatic forces affect both settings, urban regions experience a permanent temperature excess. These findings have important implications for urban planning and climate adaptation plans, underlining the need for focused measures to address the compound effects of climate change and urban heat.