GREEN ROOFS: NATURAL INFRASTRUCTURE FOR MORE SUSTAINABLE CITIES

April 29, 2025 – The webinar “Green Roofs: Natural Infrastructure for More Sustainable Cities”, promoted by Azienda Speciale Centro Italia and the University of Tuscia, highlighted the strategic role of green roofs in tackling climate change and improving urban well-being.

“Green roofs represent a natural infrastructure capable of delivering important ecosystem services,” emphasized Andrea Colantoni, Professor at the University of Tuscia and Erasmus+ GREENO2 Project Coordinator, “such as carbon dioxide absorption, trapping of particulate matter and air pollutants, and the reduction of urban temperatures thanks to the insulating effect and transpiration of plants.”

During the event, the urgency of action in cities was underscored: although they occupy only 2–3% of the Earth’s surface, cities are responsible for over 60% of global greenhouse gas emissions. With 55% of the world’s population currently living in urban areas – a figure expected to rise by 2050 – green infrastructure, starting with rooftops, plays a strategic role in mitigating the urban heat island effect and improving air quality.

Plants, in fact, are not only “green lungs” but also “urban livers,” capable of phytoremediation by absorbing PM10, PM2.5, and various harmful substances affecting human health. According to the data shared, air pollution is responsible for around 7 million premature deaths worldwide each year. In this context, even the presence of greenery in indoor spaces – such as offices or schools – can significantly contribute to well-being and quality of life.

An extensive green roof, with an 8–15 cm substrate, requires minimal maintenance while offering significant benefits: a vegetated cover can maintain summer temperatures between 25–30°C, compared to 80°C for a conventional roof, and also provides thermal insulation in winter. Installation costs range between €40 and €100 per square meter, depending on the type and selection of plant species.

Technical data on carbon sequestration were also presented, showing that it can range from 5 to over 150 kg per plant per year, depending on the species, leaf density, and environmental conditions. The Erasmus+ GREENO2 project, coordinated by the University of Tuscia, along with the activities of the MechHydroLab experimental laboratory, are two significant examples of the university’s commitment to both environmental education and applied research, with the goal of integrating science, urban planning, and sustainability.

During the webinar, Luigi Pagliaro, expert in public policy for ecological transition, also announced the upcoming launch of a call for green surface vouchers to support Italian local businesses interested in investing in natural solutions and green infrastructure.

As part of its commitment to promoting ecological transition, Azienda Speciale Centro Italia, in collaboration with the Order of Agronomists and Foresters of Viterbo and with the support of the Chamber of Commerce of Rieti Viterbo, organized two free online seminars on April 8 and 29, 2025, focusing on “Agrivoltaics” and “Green Roofs.” The webinars, accredited by ODAF Viterbo, featured Professor Andrea Colantoni from the University of Tuscia and were held within the framework of the LIFE COMANAGE and Erasmus+ GREENO2 projects, aiming to promote sustainable innovation and environmental awareness across academia and professional communities.

For additional information, see the Azienda Speciale Centro Italia website: https://www.aziendacentroitalia.it/transizione-ecologica-focus-su-agrivoltaico-e-tetti-verdi/