Global evolution of urban microclimate research over five decades
摘要
Urbanization has significantly altered microclimates, intensifying environmental challenges and climate-related risks. Over the past five decades, urban microclimate research has grown rapidly but remains fragmented due to methodological, spatial, and data limitations. This bibliometric analysis critically assesses the global trajectory of urban microclimate studies, utilizing Scopus data covering 2395 publications from 1972 to 2024. Findings reveal a consistent publication growth, with a sharp rise in recent years and a peak in 2022 (302 publications). Research is dominated by five countries: China, the United States of America, Italy, the United Kingdom, and Germany, which account for over 60% of total output. Keyword co-occurrence and overlay analyses indicate that machine learning and deep learning have emerged as prominent and increasingly influential methodological approaches in recent urban microclimate research, complementing well-established simulation tools such as ENVI-met and Computational Fluid Dynamics (CFD). Evolving microclimate indicators increasingly extend beyond conventional air temperature to emphasize Land Surface Temperature (LST), Mean Radiant Temperature (MRT), and human-centered thermal indices such as Physiological Equivalent Temperature (PET), reflecting a growing focus on surface–atmosphere interactions, thermal comfort, and Urban Heat Island (UHI) dynamics. Thematic trends highlight a growing emphasis on urban sustainability and climate adaptation, but there is a notable lack of studies in cold-climate contexts. Despite advancements, gaps remain in the geographical disparities, contexts, and methodological aspects. This review offers strategic insights into the evolution of urban microclimate research and recommends more inclusive, technologically integrated, and climate-responsive frameworks for future investigations.