Reforestation and de-paving. These are the buzzwords of summer 2026, as an antidote to urban heat islands. We discussed this two years ago on this blog, when we reported on the experiences of Place de Catalogne in Paris – an urban forest opened in 2024 just a stone’s throw from the Eiffel Tower – and London, which in 2019 became the world’s first ‘national park city’, helping to mitigate the lethal effects of urban heat. Today – with temperatures having already reached unprecedented and unsustainable levels since May, forcing Parisians to cover their windows with thermal blankets for shelter – the issue is highly topical. Reforestation and the removal of paving can lead to a reduction in temperatures of up to 4 °C.
ISPRA and CNR have published the results of simulations carried out as part of the MIRIFICUS project (Monitoring of Reforestation Measures to Combat the Urban Heat Island Effect via Satellites) in the Rome and Florence areas, where the introduction of heat-reflective paving, the creation of new green spaces and the planting of new trees lead to a significant drop in temperatures during the hottest hours of the day. The areas selected are Settecamini and Mercafir/Piazza Artom: between 9 am and 3 pm, the difference between the actual temperature and the simulated temperature exceeds 4 °C. Furthermore, it has been demonstrated that this is not a temporary effect, but a sustained one, with the temperature reduction remaining stable at around 2–2.2 °C.
The project – which is supported by the Italian Space Agency – shows that, as stated by those who initiated the simulation, ‘tackling heat islands is not just an environmental necessity, but a real opportunity to make cities cooler and more liveable through simple solutions’. In short: more trees, more natural soil, surfaces that do not heat up, and urban planning that takes the data into account.
This demonstrates that in Rome, where the summer surface temperature in the urban area averages 43.7 °C, the cooling effect of the simulated intervention is already evident from the morning onwards. And that in Florence, which has an average urban temperature of over 44 °C, the drop is more than 4 °C. In short, even in the most heavily built-up areas, an improvement in the microclimate is possible.
Rome and Florence are merely the cities chosen for the simulations. In almost all major Italian cities, summer temperatures exceed 40 °C, because concrete and tarmac, combined with a lack of natural soil and vegetation, and impervious surfaces, trap heat. Indeed, rural areas show an average temperature that is 5.6 °C lower than in cities.
