As record heat waves continue to bake concrete jungles across the globe, city planners looking for thermal relief may find their best tool planted right outside their front doors. According to new research from Korea’s National Institute of Forest Science, urban forests serve as powerful, natural air conditioners, slashing daytime temperatures by nearly 2 degrees Celsius compared to heavily built-up city centers. The findings, released Monday by the forest research agency, draw on continuous temperature and humidity tracking across various urban environments in Seoul. The data reveals that city forests provide a consistent cooling effect, lowering temperatures by up to 1.8 degrees Celsius at the peak of midday heat. However, not all green spaces cool equally. Researchers discovered that broadleaf and mixed forests — composed of both deciduous and coniferous trees — offered the most dramatic heat reduction, cooling surrounding areas by 1.5 to 1.8 degrees Celsius. Coniferous stands were slightly less effective, lowering temperatures by about 1.2 degrees Celsius. Scientists attribute