A wide-ranging environmental and energy sustainability project is underway at the Papal Basilica of St. Peter in the Vatican, aimed at reducing emissions, improving air quality, and promoting sustainable practices—ten years after Pope Francis issued the landmark encyclical Laudato Sì.
The project, launched in 2022 by the Fabbrica di San Pietro, involves the Basilica and nearby Vatican buildings including Palazzo della Canonica, Palazzo di Santa Marta, and the Studio del Mosaico. The initiative is part of the Vatican’s broader efforts to promote “Integral Ecology” and respond to the climate crisis.
“The sustainability project for the monumental complex of St. Peter’s Basilica aims to make the Vatican Basilica, with the community that animates it and the millions of pilgrims and tourists who visit it every year, a zero-impact ‘home’, which welcomes everyone and encourages everyone to grow in humanity,” said Cardinal Mauro Gambetti, President of the Fabbrica di San Pietro.
Collaboration with Italian institutions such as ENEA, the Polytechnic University of Milan, and the University of Bari “Aldo Moro” has yielded the first results of the project, particularly in the areas of material and energy flow management.
ENEA’s “Resource Diagnosis” assessed material and water usage in the involved buildings and proposed measures such as improved waste segregation, the installation of water fountains to eliminate plastic containers, and the replacement of non-biodegradable packaging. The initiative is being positioned as a replicable model for other heritage and religious sites.
In terms of energy management, the Polytechnic University of Milan proposed upgrades to lighting and ventilation, including the use of LED lamps and heat pumps. At the Palazzo della Canonica, consumption is projected to decrease by up to 57%, while emissions could fall by as much as 72%. At the Studio del Mosaico, proposed upgrades may lead to energy savings of more than 60%.
Overall, the plan is expected to reduce energy consumption by 43% and carbon dioxide emissions by 62%.
A significant part of the initiative is the continuous monitoring of indoor air quality inside St. Peter’s Basilica. In collaboration with the University of Bari, advanced sensors have been installed at seven points within the Basilica to monitor levels of particulate matter, carbon dioxide, volatile organic compounds, polycyclic aromatic hydrocarbons, and microclimatic conditions.
Despite hosting between 40,000 and 45,000 visitors per day, the data so far indicates that the Basilica maintains “good air quality” due to its size and natural ventilation.
Cardinal Gambetti emphasized that “the Vatican City State has been committed for many years to promoting sustainable development through ecological policies to safeguard the environment and provide energy saving strategies, in the spirit of the principles of the Encyclical Laudato Sì, the Apostolic Exhortation Laudate Deum and the Encyclical Fratelli Tutti.”
Walter Ganapini, the project coordinator, added that the Scientific Project Committee “has validated methodologies and projects in the energy and environmental fields, monitors, reports and certifies the results of the actions, then contributing, with information and training tools consistent with the United Nations 2030 Agenda, also to interreligious dialogue, adhering to the ‘One Health’ approach.”
