How much Urban Green do Bavarian cities need to cool by 1 degree?

Kurzfassung

Urban environments are becoming increasingly susceptible to the adverse effects of climate change, with the urban heat island (UHI) effect amplifying temperature extremes and intensifying environmental challenges. This study examines the potential of urban greening to mitigate land surface temperatures (LST) across Bavaria’s 44 largest cities by leveraging Landsat satellite data from 2013 to 2023 in conjunction with a spatial regression model. The research quantifies how green space, as measured by the Normalized Difference Vegetation Index (NDVI), influences LST. The spatial regression model, which accounts for spatial dependencies, explains approximately 87% of the variation in LST, outperforming traditional Ordinary Least Squares (OLS) regression. Notably, the study finds that an increase of 0.0243 in NDVI for the city and an increase of 0.0316 in NDVI in residential areas within the city is associated with a 1°C reduction in LST. These findings offer a clear, quantifiable benchmark for designing targeted greening strategies, particularly in areas with low NDVI. The insights generated by this research equip local authorities with actionable guidance to develop robust climate adaptation strategies tailored to the specific needs of urban areas, ultimately contributing to the creation of more resilient and sustainable cities in the face of climate change.