Increased urban thermal discomfort in major Cities of the Arabian Peninsula

Abstract Urban thermal discomfort is an escalating concern, particularly in arid cities undergoing rapid urbanization and climate change. Addressing this issue is essential for enhancing urban resilience and livability in vulnerable arid environments, like the Arabian Peninsula (AP). This study leverages Google Earth Engine, remote sensing datasets, and advanced thermal indices to evaluate spatiotemporal variations in urban thermal discomfort across 13 cities of the AP from 1990 to 2024. The results indicate that although many cities achieved a 20–40% increase in vegetation cover, localized land degradation persists in Abha and Sanaa (5–10%). This spatial disparity in vegetation recovery has influenced urban heat dynamics. Inland cities, including Riyadh, Madinah, and Makkah, exhibit the highest increases in Land Surface Temperature (LST), while cities at higher elevations and coastal locations benefit from natural cooling effects. Interestingly, highly urbanized areas often recorded lower Urban Heat Island (UHI) effects than peri-urban and rural areas, suggesting that dense urban morphology and materials with high thermal inertia can mitigate localized heating. The analysis of the Urban Thermal Field Variance Index (UTFVI) reveals that over 80% of urban areas experience high or extreme thermal stress; however, Doha, Muscat, and Sharjah demonstrate significant reductions through strategic urban greening and planning, as seen earlier through a few case studies in the region. This paper offers critical insights into sustainable urban planning and climate adaptation strategies to improve urban thermal comfort and livability in arid cities. Future research should integrate detailed land use assessments, seasonal and nocturnal thermal analyses, and dynamic modeling of key indices to accurately understand urban thermal dynamics.