Nestled within the Vatican’s summer retreat, the Papal Palace of Castel Gandolfo, lies a serene and secluded garden. This historic spot, complete with ancient Roman ruins, meticulously pruned hedges, a tranquil goldfish pond, and a solitary statue of the Virgin Mary, has long served as a hallowed space for popes to contemplate profound matters and seek divine wisdom.
The newest pontiff, Pope Leo XIV, has found these very grounds and garden to be a cherished sanctuary for reflecting on the natural world. It is here, at Castel Gandolfo, that he is scheduled to deliver his inaugural address on climate change this Wednesday.
Though his previous statements on the topic have been concise, they were undeniably powerful. Just weeks ago, Pope Leo asserted that “grave inequalities and the greed that fuels them are spawning deforestation, pollution, and the loss of biodiversity.” He further emphasized that “extreme natural phenomena caused by climate changes provoked by human activity are growing in intensity and frequency.”
However, his upcoming remarks at Wednesday’s climate conference are anticipated to be his most comprehensive exposition on the subject to date. These words will be scrutinized closely, as they coincide with the tenth anniversary of ‘Laudato Si,’ a pivotal papal document from his predecessor, Francis. This encyclical significantly updated the Catholic Church’s teachings to directly confront the challenges of climate change.
This seminal document, an encyclical, implored Catholics worldwide to embark on a “profound interior conversion,” urging them to re-evaluate how consumer culture impacts the planet’s well-being. Its release strategically preceded the monumental Paris Agreement, where global leaders committed to capping global warming at less than 2 degrees Celsius above pre-industrial levels.
The 2015 encyclical was broadly interpreted as a significant influence on the Paris negotiators, with at least ten world leaders referencing ‘Laudato Si’ in their speeches at the U.N. climate summit. Pope Leo’s forthcoming address will reveal whether he intends to merely reiterate Francis’s environmental message or introduce his unique perspective to the ongoing discourse.
While the Vatican’s direct influence on global climate policy might be limited, its moral authority is immense. With nearly a fifth of the world’s population identifying as Catholic and the Church owning land greater in total area than the state of Texas, its potential to inspire action is considerable.
Francis endeavored to extend this influence beyond the Church’s immediate congregation, though not always with success. For instance, in 2017, he implored President Trump to remain in the Paris Agreement, an appeal that ultimately went unheeded. Later, in 2023, amidst a decline in global cooperation following the pandemic, Francis issued a 13-page update to ‘Laudato Si,’ essentially expressing regret that his initial calls for action had largely been ignored.
Observers of the Vatican note that Pope Leo’s stances on other crucial issues have often been ambiguous. However, when it comes to climate change, his deep concern is unmistakable, especially regarding its severe and unequal impact on impoverished and vulnerable communities.
This past summer, he personally endorsed an initiative to power the entire Vatican with solar energy. In September, he unveiled a sprawling 55-acre educational center within the Castel Gandolfo gardens. This center is dedicated to promoting sustainable farming practices, ecological responsibility, and other principles outlined in ‘Laudato Si.’
During a homily delivered in one of these gardens, Pope Leo addressed the center’s staff and various Vatican officials, stating, “we must pray for the conversion of many people inside and outside the Church who still do not recognize the urgency of caring for our common home.” He linked the escalating intensity and frequency of natural disasters and climate uncertainty to “human excesses in our lifestyle, everything we do.”
On a more personal note, Pope Leo’s frequent use of this secluded garden underscores his view of it as a “natural cathedral,” a meditative sanctuary also favored by previous popes. For example, in 2003, after a day of reflection in the garden, John Paul II dispatched an envoy to President George W. Bush, imploring him against invading Iraq. A decade later, Benedict XVI reportedly considered his declining health and the possibility of retirement within these very same quiet confines, according to Reverend Manuel Dorantes, the management director of the Laudato Si Higher Education Center.
This week’s conference, held adjacent to the Papal Palace, will feature Pope Leo alongside a distinguished roster of fervent advocates for comprehensive policies designed to combat climate change’s root cause: the escalating combustion of fossil fuels and the greenhouse gases they release into our atmosphere.
Among the notable speakers are Laurence Tubiana, widely recognized as the architect of the Paris Agreement; Bill McKibben, an acclaimed author and leading climate activist; Katharine Hayhoe, a celebrated climate scientist; and Marina Silva, Brazil’s outspoken Minister of Environment and Climate Change. Also expected to be in attendance is Arnold Schwarzenegger, the actor and former California governor known for his strong stance on environmental issues.
Given that ‘Laudato Si’ is a body of teachings rather than a specific call to action, its tangible impact over the last decade is challenging to quantify. However, Ms. Hayhoe notes that the Church can be a powerful catalyst for profound shifts in perspective, a truth she experienced firsthand.
“The motivation to act comes from the heart. I’m a scientist, and that’s true for me too,” she explained. “My journey to becoming a climate scientist was driven by passion – I initially intended to pursue astrophysics. As a Christian, I firmly believe that a serious interpretation of the Bible compels us to be at the forefront of demanding climate action.”
Lorna Gold, who heads the Vatican-affiliated Laudato Si Movement and is organizing this conference, noted that before Francis’s encyclical, climate change was largely a ‘niche topic’ within Catholic discourse. Yet, in the wake of ‘Laudato Si,’ significant practical actions have emerged. For instance, Ireland’s bishops committed to divesting their churches from fossil fuel investments and rewilding 30 percent of all parish-owned land.
“Such initiatives have truly captured the public imagination,” Ms. Gold remarked.
Across the Catholic Church, from cardinals to bishops, particularly in the rapidly growing congregations of Asia, Latin America, and Africa, there’s a shared and explicit demand for urgent climate action, echoing the sentiments of both Francis and Leo.
In a powerful display of unity, regional bishops’ conferences from these three continents released a joint document in July, boldly titled “A call for climate justice and the common home: ecological conversion, transformation and resistance to false solutions.” Cardinal Filipe Neri Ferrão, Archbishop of Goa and Daman in India, articulated the statement’s core message as “a call to conscience in the face of a system that threatens to devour creation, as if the planet were just another commodity.”