In the serene, secluded gardens of the Papal Palace of Castel Gandolfo, a place historically favored by popes for deep reflection and prayer, Pope Leo XIV will deliver his inaugural address on climate change this Wednesday. Amidst ancient Roman ruins, meticulously pruned hedges, and a peaceful pond, this location has become a personal sanctuary for the new pontiff to contemplate the state of nature.
While Pope Leo XIV has previously touched upon environmental concerns with urgency, stating that “grave inequalities and the greed that fuels them are spawning deforestation, pollution and the loss of biodiversity,” and acknowledging the increasing intensity of climate-induced extreme weather, his upcoming speech is anticipated to be his most comprehensive statement yet. This address is particularly significant as it coincides with the 10th anniversary of “Laudato Si’,” a groundbreaking encyclical from his predecessor, Pope Francis, which explicitly integrated climate change into Catholic teachings.
Pope Leo XIV feeding fish at Castel Gandolfo a few weeks ago. (Pool photo by Filippo Monteforte)
“Laudato Si'” implored Catholics worldwide to undergo a “profound interior conversion,” encouraging a reevaluation of consumer culture’s impact on planetary health. Issued just months before the Paris Agreement, where nations committed to limiting global warming, the 2015 encyclical served as a powerful call to action. Several world leaders referenced “Laudato Si'” during the United Nations climate gathering that year. Pope Leo XIV’s forthcoming remarks will indicate whether he intends to simply uphold Francis’s environmental legacy or introduce a fresh perspective to the Vatican’s engagement with climate issues.
Despite the Vatican’s limited direct influence on global climate policies, its moral authority is considerable, with nearly a fifth of the world’s population identifying as Catholic. The church’s landholdings alone exceed the size of Texas. Pope Francis actively sought to leverage this influence beyond the church’s traditional boundaries, though not always successfully. For instance, his appeal to President Trump in 2017 to reconsider withdrawing from the Paris Agreement went unheeded. In 2023, amidst waning global cooperation, Francis issued an update to “Laudato Si’,” largely expressing sorrow over the document’s unfulfilled impact.
Leo’s speech this week may show whether he is inheriting his predecessor’s language on climate, or taking a different path. (Filippo Monteforte/Agence France-Presse — Getty Images)
Vatican observers note that while Pope Leo XIV’s stances on many significant matters have remained elusive, his passion for climate change and its disproportionate impact on the poor and vulnerable is undeniable. This summer, he approved a plan for the Vatican to transition entirely to solar power. In September, he inaugurated a 55-acre educational center at Castel Gandolfo, dedicated to sustainable farming, ecological stewardship, and the principles of “Laudato Si’.”
During a homily in the garden, he urged the center’s staff and Vatican officials to “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 emphasized that escalating natural disasters and climatic instability are “largely or partly caused by human excesses in our lifestyle, everything we do.”
This secluded garden, which Leo affectionately calls a “natural cathedral,” holds a history of profound papal deliberations. In 2003, Pope John Paul II dispatched an envoy to President George W. Bush from this very garden, advocating against the invasion of Iraq. A decade later, Benedict XVI pondered his retirement due to declining health here, as recounted by Rev. Manuel Dorantes, director of the Laudato Si’ Higher Education Center.
This week’s conference, held near the historic palace, will draw a distinguished roster of climate action advocates. Speakers include Laurence Tubiana, a key architect of the Paris Agreement; renowned author and activist Bill McKibben; prominent climate scientist Katharine Hayhoe; and Brazil’s outspoken Minister of Environment and Climate Change, Marina Silva. Actor and former California Governor Arnold Schwarzenegger is also expected to be in attendance.
Lorna Gold, who spearheads the Vatican-affiliated Laudato Si’ Movement, which is organizing the conference, points out that before Francis’s encyclical, climate change was a marginal topic within Catholic circles. Since its release, however, tangible actions have emerged, such as Irish bishops committing to divest from fossil fuels and rewilding 30 percent of parish-owned land. “That has really caught the imagination of people,” Gold remarked.
A mural in Albano, Italy, depicted Leo’s predecessor cleaning the sky of pollution in 2019. (Andrew Medichini/Associated Press)
Ms. Hayhoe, a scientist, acknowledges that the motivation to act on climate often originates from the heart, even for her. “The reason I became a climate scientist was from the heart – I was planning to become an astrophysicist. Being a Christian, I believe that if we take the Bible seriously we’d be at the front of the line, demanding action.” This sentiment underscores the potential for deep-seated shifts in perspective that the Church can inspire.
The Catholic Church’s hierarchy, particularly cardinals and bishops in rapidly growing regions like Asia, Latin America, and Africa, have echoed Francis and Leo’s calls for climate action. In July, regional bishops’ conferences from these continents released a joint document 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.”