Pope Leo XIV visits a field where the Vatican is studying setting up a solar farm on land surrounding the Vatican Radio shortwave transmission center at Santa Maria di Galeria outside of Rome June 19, 2025. (CNS/Vatican Media)
Stephanie Clary
When Pope Leo XIV first appeared on the balcony above St. Peter's Square 100 days ago today, little was initially known about the former Cardinal Robert Prevost, an Augustinian from Chicago who spent decades ministering in Peru.
In the ensuing three and a half months, many people have watched closely the direction of his burgeoning papacy, particularly how it would follow, or diverge from, the priorities of his predecessor Pope Francis, who made environmental concern one of the pillars of his 12 years as head of the Roman Catholic Church.
Leo's first 100 days as pope have provided early insight into how he will engage with the environmental crises facing the planet, from climate change, to deforestation and pollution, to the impacts of a new technological revolution on the health of ecosystems and communities.
Already, Leo has celebrated the first-ever liturgy under a new Vatican-approved Mass for the Care of Creation and issued his message for the 2025 World Day of Prayer for the Care of Creation, celebrated Sept. 1. He has spent part of the summer at the papal villa in Castel Gandalfo, and paid visits to the Borgo Laudato Si' sustainable ecology area established by Francis. He also has toured the land where the Vatican is constructing a vast solar farm capable of fully powering Vatican City and making it the first carbon-neutral nation.
Since his papacy began on May 8, Leo has referenced environmental matters both in brief comments as part of larger speeches and messages, and through addresses focused specifically on the health of planet Earth and its inhabitants.
Pope Leo XIV celebrates Mass for the Care of Creation on the grounds of the Borgo Laudato Si' ecology center in Castel Gandolfo, Italy, July 9, 2025. (CNS/Cristian Gennari, pool)
Some themes have emerged.
A prominent approach from Leo has been to frame care for creation as justice, and to call environmental protection an essential piece of Christian life, as Francis did.
Environmental justice — implicitly proclaimed by the prophets — can no longer be regarded as an abstract concept or a distant goal. It is an urgent need that involves much more than simply protecting the environment. For it is a matter of justice — social, economic and human. For believers it is also a duty born of faith, since the universe reflects the face of Jesus Christ, in whom all things were created and redeemed. In a world where the most vulnerable of our brothers and sisters are the first to suffer the devastating effects of climate change, deforestation and pollution, care for creation becomes an expression of our faith and humanity.
— Message for the 2025 World Day of Prayer for the Care of Creation, June 30
The prophet [Isaiah] contrasts justice and law with the desolation of the desert. His message is extraordinarily timely, given the evidence in various parts of the world that our earth is being ravaged. On all sides, injustice, violations of international law and the rights of peoples, grave inequalities and the greed that fuels them are spawning deforestation, pollution and the loss of biodiversity. Extreme natural phenomena caused by climate changes provoked by human activity are growing in intensity and frequency (cf. Laudato Deum, 5), to say nothing of the medium and long-term effects of the human and ecological devastation being wrought by armed conflicts. As yet, we seem incapable of recognizing that the destruction of nature does not affect everyone in the same way. When justice and peace are trampled underfoot, those who are most hurt are the poor, the marginalized and the excluded. The suffering of indigenous communities is emblematic in this regard.That is not all. Nature itself is reduced at times to a bargaining chip, a commodity to be bartered for economic or political gain. As a result, God's creation turns into a battleground for the control of vital resources.
— Message for the 2025 World Day of Prayer for the Care of Creation, June 30
Our mission to care for creation, to foster peace and reconciliation, is Jesus' own mission, the mission that the Lord entrusts to us. We hear the cry of the earth and we hear the cry of the poor, because this plea has reached the heart of God. Our indignation is his indignation; our work is his work.
— Homily for the Mass for the Care of Creation, July 9
Leo has often linked environmental destruction to other issues facing the world. In that way, he has reflected the idea of "integral ecology" that was amplified by Francis with his 2015 encyclical "Laudato Si', on Care for Our Common Home," which emphasizes how social and environmental challenges are interrelated.
For instance, Leo has talked about environmental destruction in the context of wars and conflicts.
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You are sowing seeds of hope in the lands of the Christian East, which today, as never before, are devastated by wars, plundered by special interests, and covered by a cloud of hatred that renders the air unbreathable and toxic.
— Address to participants in the plenary session of the "Reunion of Aid Agencies for the Oriental Churches", June 26
Pope Francis spoke of a "polycrisis" in describing the dramatic nature of our own age, marked by wars, climate change, growing inequalities, forced and contested migration, stigmatized poverty, disruptive technological innovations, job insecurity and precarious labour rights. On such important issues, the Church's social doctrine is called to provide insights that facilitate dialogue between science and conscience, and thus make an essential contribution to better understanding, hope and peace.
— Address to members of the "Centesimus Annus Pro Pontifice" foundation, May 17
Brothers and sisters, I would like that our first great desire be for a united Church, a sign of unity and communion, which becomes a leaven for a reconciled world. In this our time, we still see too much discord, too many wounds caused by hatred, violence, prejudice, the fear of difference, and an economic paradigm that exploits the Earth's resources and marginalises the poorest.
— Homily for the beginning of the pontificate of Pope Leo XIV, May 18
We are currently witnessing with despair the iniquitous use of hunger as a weapon of war. Starving people to death is a very cheap way of waging war. That is why today, when most conflicts are not fought by regular armies but by groups of armed civilians with few resources, burning land and stealing livestock, blocking aid are tactics increasingly used by those who seek to control entire unarmed populations. Thus, in this type of conflict, the first military targets become water supply networks and communication routes. Farmers are unable to sell their produce in environments threatened by violence, and inflation soars. This leads to huge numbers of people succumbing to the scourge of starvation and perishing, with the aggravating circumstance that, while civilians languish in misery, political leaders grow fat on the profits of the conflict.
— Message to participants in the 44th session of the U.N. Food and Agriculture Organization Conference, June 30
Leo has spoken of the environmental impacts of a new industrial revolution around clean energy, as well as revolutions in technology and artificial intelligence.
This portrait of Pope Leo XIII, pontiff from 1878 to 1903, shows him holding a quill pen. In 1891, Pope Leo XIII articulated his vision of Catholic social teaching impacting the affairs of our world. (CNS/Library of Congress)
I chose to take the name Leo XIV. There are different reasons for this, but mainly because Pope Leo XIII in his historic Encyclical Rerum Novarum addressed the social question in the context of the first great industrial revolution. In our own day, the Church offers to everyone the treasury of her social teaching in response to another industrial revolution and to developments in the field of artificial intelligence that pose new challenges for the defence of human dignity, justice and labour.
— Address to the College of Cardinals, May 10
Truth, then, does not create division, but rather enables us to confront all the more resolutely the challenges of our time, such as migration, the ethical use of artificial intelligence and the protection of our beloved planet Earth. These are challenges that require commitment and cooperation on the part of all, since no one can think of facing them alone.
— Audience to members of the diplomatic corps accredited to the Holy See, May 16
The occasion of the 10th anniversary of Laudato Si' this year has offered Leo opportunities to reference his predecessor Francis, and he has done so numerous times — a sign of continuity between the two popes on environmental issues.
Resisting all forms of indifference, [the Holy See diplomatic work] appeals to consciences, as witnessed by the constant efforts of my venerable predecessor, ever attentive to the cry of the poor, the needy and the marginalized, as well as to contemporary challenges, ranging from the protection of creation to artificial intelligence.
— Audience to members of the diplomatic corps accredited to the Holy See, May 16
Ten years ago, Pope Francis signed the Encyclical Letter Laudato Si', devoted to care for our common home. It has had an extraordinary impact, inspiring countless initiatives and teaching everyone to listen to the twofold cry of the Earth and of the poor.
— Regina Caeli in St. Peter's Square, May 25
Pope Leo XIV greets María Lía Zervino, a member of the council of the Laudato Si' Movement, and Lorna Gold, executive director, after his weekly general audience in St. Peter's Square at The Vatican May 28, 2025. (OSV News/Simone Risoluti, Vatican Media/Catholic Press Photo)
In a divided and troubled world, the Holy Spirit teaches us to walk together in unity. The earth will rest, justice will prevail, the poor will rejoice and peace will return, once we no longer act as predators but as pilgrims. No longer each of us for ourselves, but walking alongside one another. Not greedily exploiting this world, but cultivating it and protecting it, as the Encyclical Laudato Si' has taught us.
— Homily for the vigil of Pentecost, June 7
Following Pope Francis, I invite you to take care of our common home, to preserve the beauty of the Great Island, whose beauty and fragility have been entrusted to you. Care for our home is an integral part of your prophetic mission. Take care of creation, which weeps, and teach your faithful the art of protecting it with justice and peace.
— Address to the bishops of Madagascar, June 16
Leo has also addressed climate change directly, including in the first video message of his pontificate, to a conference of Catholics in Latin America preparing for the upcoming United Nations climate summit, to be held in Belém, Brazil, in November.
I know you are about to carry out synodal work of discernment in preparation for COP30. You will reflect together on a possible remission of the public debt and of the ecological debt, a proposal that Pope Francis had suggested in his message for the World Day of Peace. And in this jubilee year, a year of hope, this message is so important. I would like to encourage you, university rectors, in this mission you have taken on: to be builders of bridges of integration between the Americas and the Iberian Peninsula, working for ecological, social and environmental justice.
— Video message to the meeting of universities in Rio de Janeiro on Laudato Si', May 20
Food systems have a major influence on climate change, and vice versa. The social injustice caused by natural disasters and the loss of biodiversity must be reversed in order to achieve a just ecological transition, that places the environment and people at the centre. To protect ecosystems and disadvantaged communities, including indigenous peoples, the mobilization of resources by governments, public and private entities, national and local agencies is needed to adopt strategies that prioritize the regeneration of biodiversity and soil richness.
— Message to participants in the 44th session of the U.N. Food and Agriculture Organization Conference, June 30
Pope Leo XIV meets with the heads of several bishops' conferences July 1, 2025, at the Vatican. From left are Indian Cardinal Filipe Neri Ferrão, president of the Federation of Asian bishops' conferences; Brazilian Cardinal Jaime Spengler of Porto Alegre, president of the Latin American bishops' council, known as CELAM; and Congolese Cardinal Fridolin Ambongo Besungu of Kinshasa, president of the Symposium of Episcopal Conferences of Africa and Madagascar, or SECAM; and other prelates. (OSV News/Mario Tomassetti, Vatican Media)
In discussing climate change and other ecological crises, Leo has stressed the need to move from words to concrete action, continuing a message he articulated while a cardinal.
Without decisive and coordinated climate action, it will be impossible to guarantee agricultural and food systems capable of feeding a growing world population. Producing food is not enough: it is also important to ensure that food systems are sustainable and provide healthy and affordable diets for all.
— Message to participants in the 44th session of the U.N. Food and Agriculture Organization Conference, June 30
To ensure peace and development, understood as the improvement of the living conditions of populations suffering from hunger, war and poverty, concrete actions are needed, rooted in serious and far-sighted approaches. We must therefore leave aside sterile rhetoric and, with firm political will, as Pope Francis said, "resolve conflicts and thus … foster a climate of reciprocal cooperation and trust for the sake of meeting common needs"
— Message to participants in the 44th session of the U.N. Food and Agriculture Organization Conference, June 30
Leo has spoken several times on the need to raise awareness and concern about environmental challenges, and of the importance of ecological education.
At the beginning of Mass, we prayed for conversion, our own conversion. I would like to add that we should pray for the conversion of the many people, inside and outside the Church, who do not yet recognize the urgent need to care for our common home. The many natural disasters we see occurring almost daily in our world, in so many places and countries, are also in part a result of the excesses of human beings and our lifestyles. We need to ask whether we ourselves are undergoing that conversion.
— Holy Mass for the Care of Creation homily, July 9
Today we are invited to listen attentively to the cry of creation. This urgency is incumbent upon all humanity, to whom God has entrusted his work. Our consciences are strongly challenged by the increasingly serious environmental damage being caused. Faced with pollution and climate change, the loss of biodiversity, the deterioration of life and social degradation, global inequalities, the lack of drinking water and access to energy for many people, ecological education is essential for all to reverse the current order.
— Message for the gathering of the Scouts et Guides de France, July 28
Through these speeches and messages delivered during his first 100 days as bishop of Rome, Leo has displayed concern for the environment and shown he is following progress, or lack thereof, in addressing ecological crises around the globe.
In late September, Leo is set to attend a Catholic conference at Castel Gandalfo marking the Laudato Si' 10-year anniversary and preparing for the U.N. climate summit in Brazil. The speech could be his most significant yet of his early papacy on the environment and care for creation.
