Urban Heat Islands: Reforestation and Depaving Can Reduce Temperatures by Up to 4°C
Urban Heat Islands: Reforestation and Depaving Can Reduce Temperatures by Up to 4°C
The MIRIFICUS project, coordinated by the Italian National Research Council (CNR-IBE) in collaboration with ISPRA and supported by the Italian Space Agency, shows that urban heat can be significantly reduced through nature-based solutions. Simulations carried out in Rome and Florence demonstrate that increasing green spaces, planting trees, and replacing heat-retaining pavements with cooler surfaces can lower daytime temperatures by more than 4°C, while maintaining an average daily reduction of about 2–2.2°C.
The project also analyzed satellite data collected between 2013 and 2023, revealing that most Italian cities experience summer surface temperatures above 40°C because of extensive asphalt, concrete, and limited vegetation. In contrast, surrounding rural areas are considerably cooler. The study highlights that urban design—including building density, height, and construction materials—plays a major role in determining local temperatures. For example, industrial areas in Rome can reach 57.2°C, whereas urban forests in Florence are almost 9°C cooler than densely built neighborhoods.
To support urban planning, MIRIFICUS has developed a free webGIS platform and a Google Earth Engine web application that allow municipalities to analyze local temperature patterns, assess the effects of land use and green spaces, and simulate the impact of mitigation measures. According to the project partners, these tools provide scientific support for designing more resilient, healthier, and climate-adapted cities.
Project MIRIFICUS