Urban Heat and Environmental Justice

The urban heat island (UHI) effect describes how cities, with their extensive dark asphalt and concrete surfaces, reduced vegetation, and waste heat from vehicles and buildings, retain and generate more heat than surrounding rural areas, often registering air temperatures several degrees Celsius higher, especially at night. The phenomenon was first systematically documented remarkably early, by the British chemist and pharmacist Luke Howard — also known for naming cloud types — in his 1818 work The Climate of London, which compared temperature records from the city center to surrounding countryside and identified the urban warming pattern that would only be formally named the "urban heat island" more than a century later.