Pope Francis, who died on Monday, April 21, 2025, aged 88, was one of the greatest climate champions we have ever had.
Pope Francis’s passing comes during the 10th anniversary of the publication of his groundbreaking encyclical Laudato Si’, which examined long-standing Catholic environmental teaching in the light of today’s planetary crisis.
Pope Francis’s leadership has borne initiatives that transformed the Catholic Church into a powerful force for action on the planetary crisis and have had an influence far beyond the Church itself.
History’s first Latin American pontiff, he used his position as the spiritual leader of 1.2 billion Catholics to educate and highlight the climate crisis from day one of his papacy.
He repeatedly drove home the moral, ethical, and spiritual issues around its causes and effects.
He urged, cajoled, and appealed repeatedly to world leaders to listen to the climate science, to reach meaningful international agreements, to deliver the transformative change needed to tackle the crisis, and to protect the poor.
Climate justice was always central to his message.
He said he was disturbed that global warming had been accompanied by a general cooling of multilateralism, a growing lack of trust within the international community, and a loss of shared awareness that we are all part of the same family of nations.
At the COP28 climate negotiations in Dubai in 2023, Pope Francis reminded global leaders that “now more than ever, the future for us all depends on the present that we choose”.
He went on to pose a question for the global leaders and climate negotiators that he asked them to answer. It was: “Are we working for a culture of life or a culture of death?”
Listen to the cry of the Earth, he told them. Hear the plea of the poor. Be sensitive to the hopes of the young. Protect the dreams of children and ensure they are not denied their future.
These were among the core messages Pope Francis delivered, not just at COP28, but right throughout his papacy.
When he was elected Bishop of Rome in 2013, Argentine Cardinal Jorge Maria Bergoglio chose the name Francis.
It was a deliberate effort to honour Francis of Assisi, the 13th-century saint, now the patron saint of all who study and work in the area of ecology.
The Pope said he was inspired by Saint Francis because his life highlighted an inseparable bond between concern for nature, justice for the poor, commitment to society, and interior peace.
Now, eight centuries later, climate change is front and centre – and represents a very real existential threat to those inseparable bonds
Pope Francis said: “The destruction of the environment is an offence against God, greatly endangers all human beings, especially the most vulnerable, and threatens to unleash a conflict between generations.”
He published two major Papal Encyclical Letters about the matter, and by so doing ensured the climate crisis is now central to the Church’s social teachings.
Papal Encyclical Letters are the highest-level teaching documents that any Pope can issue.
His first climate change Encyclical was published in 2015. It is called “Laudato Si”, which means “Praise be to You”.
It is a term directly from the “Canticle of the Creatures” by Saint Francis of Assisi.
In this document, Pope Francis said the Earth is like a sister or mother who sustains and governs us. He then lamented the harm people now inflict on the Earth through the irresponsible use and abuse of the good things it offers.
He said we have come to see ourselves as lords and masters of the Earth, entitled to plunder it at will.
Soil, water, air, and all forms of life are now sick, and the Earth is among the most abandoned and maltreated of our poor.
“It is beginning to look more and more like an immense pile of filth.
“In many parts of the planet, the elderly lament that once beautiful landscapes are now covered with rubbish.
“Industrial waste and chemical products utilised in cities and agricultural areas can lead to bioaccumulation in the organisms of the local population, even when levels of toxins in those places are low.
“Frequently no measures are taken until after people’s health has been irreversibly affected.
“These problems are closely linked to a throwaway culture, which affects the excluded just as it quickly reduces things to rubbish,” he said.
Laudato Si’ was published ahead of negotiations for the Paris agreement in May 2015, and Pope Francis engaged in diplomacy to ensure the accord’s passed with a reference to keeping global temperatures below the threshold of 1.5C This benchmark temperature has had a significant impact on ensuring climate ambition since. The agreement passed, and the Holy See is a party to it.
The Laudato Si’ Action Platform, which was launched by Pope Francis, has spurred a wide range of Catholic institutions to develop practical plans for action on ecology, touching 20 million people to date.
Care for creation has become an increasingly important part of how Catholics live their faith. The ecumenical Season of Creation and annual Laudato Si’ Week, which are co-sponsored by the Vatican, and the World Day of Prayer for the Care of Creation, for which Pope Francis issued annual messages, engage millions of people each year in prayer and action for our common home on these occasions. These exemplify how the message is now mainstream in Catholic life.
Pope Francis inspired many other faith leaders and faithful to take action for creation, breathing new life into the global “faith environment” movement. Faith-led action on the environment has increased significantly since 2015. Ahead of COP21 in 2021, Pope Francis hosted 50 faith leaders at the Vatican, which led to a groundbreaking multi-faith statement. Other significant developments include the publication Al Mizan, which is known as the “Muslim Laudato Si’”.
Laudato Si’ was the inspiration behind Laudato Si’ Movement, which was named by Pope Francis himself. This global movement is leading community-based initiatives across 140 countries. The organisation’s documentary featuring Pope Francis and frontline leaders has been seen by well over 10 million people.
Eight years later, in 2023, Pope Francis published his second encyclical letter about climate change.
This one was called “Laudato Deum”, meaning “In praise of God”.
It was published on October 4, which is the feast day of Saint Francis of Assisi.
“Laudato Deum” was yet another urgent cry from Pope Francis for global climate action, which he said has become more pressing than ever before.
It highlighted again how the effects of climate change are borne by the most vulnerable people and said every family ought to realise that the future of their children is at stake.
He said the situation is close to breaking point and the world is not reacting fast enough.
In one passage he described it as “chilling” to realise that technology has given those with the economic resources “an impressive dominance over the whole of humanity and the entire world”.
It is extremely risky for a small part of humanity to have such a power, he said.
He also took a very clear swipe at some of the richest countries in the world, who place economic and business objectives above the need for climate action.
“The climate crisis is not exactly a matter that interests the great economic powers, whose concern is the greatest profit possible at minimal cost, and in the shortest amount of time,” he wrote.
The Holy Father highlighted that greenhouse gas “emissions per individual in the United States are about two times greater than those of individuals living in China, and about seven times greater than the average of poor countries”.
He shared the global sense of frustration about the slow pace of agreement at international climate negotiations.
He said these negotiations “cannot make significant progress due to positions taken by countries that place their national interests above the global common good”.
This he called “a failure of conscience and responsibility” that “will not be forgotten”.
Pope Francis also pushed back against any attempt to link climate change to population growth in poorer countries.
“It is not the fault of the poor, since the half of our world that is most needy is responsible for scarcely 10% of toxic emissions, while the gap between the opulent few and the masses of the poor has never been so abysmal. The poor are the real victims of what is happening,” he said.
Pope Francis told global leaders that in the end the purpose of being in power is to serve. He said it is useless to cling to an authority that will one day be remembered for its inability to act on climate change when it was urgent and necessary to do so.
Reactions have trailed the Pope’s passing.
Mark Campanale, founder and director of Carbon Tracker, said: “Pope Francis’s legacy goes far beyond the body of the Catholic Church. As a visionary leader, he sparked lasting momentum for a just transition away from fossil fuels and towards lasting sources of renewable energy. Although we’ve lost a great leader, the seeds of an ethical vision for this planet, our common home, will continue to bear fruit in the years to come.”
Tzeporah Berman, founder and chair of the steering committee of the Fossil Fuel Nonproliferation Treaty, said: “There is no doubt that Pope Francis made a huge impact on progress towards a future without fossil fuels. His moral authority stands in stark contrast to governments that want to put their heads in the sand and pretend that climate change isn’t happening. His leadership has shed new light on the climate crisis that affects us all.”
Bill McKibben, founder of 350.org and Third Act, said: “Pope Francis – informed by science and scripture – understood many things deeply, one of them solar energy. Under his leadership, he moved to make sure Vatican City will soon be the only nation on earth powered entirely by the sun, and he did it in a letter (Fratello Sole) that makes specific reference to his namesake in Assisi and his Canticle of the Sun. The world has lost a great champion, but he left a light shining!”
Mary Robinson, former President of Ireland and founder of Project Dandelion, said: “I met with Pope Francis on several occasions, and among many qualities, I respected his leadership on climate justice. Pope Francis reminded us that the climate crisis is not only an environmental emergency – it is a moral challenge. He spoke out many times about the climate and nature crisis, raising his voice for those least responsible yet most affected: the poor, the marginalised, and future generations.
“With the courage of his convictions, he called us to care for our common home and to recognise that the fate of the Earth and the fate of humanity are one and the same. His leadership urged a new kind of solidarity – rooted in compassion, justice, and the deep understanding that we are all connected.”
Monsignor Eric de Moulins-Beaufort, President of the French Bishops’ Conference, said: “Laudato Si’, published in June 2015 just before COP21 in Paris, was a tremendous catalyst for Catholic engagement, both worldwide and particularly in Paris in the lead-up to the COP. Many initiatives that were being prepared suddenly found an echo in parishes, were joined by enthusiastic volunteers, and gained credibility. As Auxiliary Bishop of Paris, I was a joyful witness to this.”
Bishop Allwyn D’Silva, Chairman of the Office of Human Development, Federation of Asian Bishops’ Conferences, said: “Long before Pope Francis, activists at the grassroots recognised that environmental problems and climate change affected the poor most, and that they are the hardest hit. However, it took a spiritual leader of Pope Francis’ statue to give a tremendous boost to integral ecology.
“In Laudato Si’ the Holy Father has elucidated the concept beautifully. He did not use high theological terms or scientific jargon to describe integral ecology. Rather, he simply stated that the cry of the earth is the cry of the poor, and thus holistic solutions are needed.”
Bishop Serverus Jjumba, Bishop of the Diocese of Masaka, Uganda, said: “Pope Francis chose to exceptionally promote integral ecology when he published, for the first time in the history of the Church, teaching on stewardship consolidated in one single document titled ‘Laudato Si’. The document was issued as an encyclical – a very high level of doctrinal authority. It was also crafted to be a document for all faiths and cultures, another vital ingredient that built synergies across the board to solve the climate crisis, an issue that must truly be everyone’s concern.”
Bishop John Keenan, President of the Catholic Bishops’ Conference of Scotland, said: “We thank God for the Pope’s service which was always human and humble in its informal style and with a message of God’s universal love and unconditional mercy that brought hope to so many. A man of the poor who lived simply, Pope Francis was a voice for the voiceless and all those who find themselves on the margins in our world.
“A man of peace, he called the Church to listen to everyone, to move forward together as a family, to find a conciliatory approach to those of different beliefs and lifestyles, for an end to conflicts across the world and for the care of Creation as God’s precious gift to humanity.”
Lorna Gold, executive director of Laudato Si’ Movement, said: “As the spiritual leader who guided our Church for 12 years, Pope Francis breathed new life into centuries of Catholic teaching. As the man who inspired me and our movement, his warmth, humility, and commitment to the common good showed us a new way forward. He sparked a sense of new hope and beginnings for many, so it’s fitting that Pope Francis passed into eternal rest during Easter, when we celebrate the renewal of all life. We pray thanks for the gift of Pope Francis and for sharing in his precious few moments on Earth.”
According to the Laudato Si’ Movement, Pope Francis’ legacy has profoundly transformed Catholics’ understanding of the relationship between humanity, creation, and the Creator. Standing on scripture, centuries of scholarship, and decades of papal statements on the environment, he brought Catholic teaching to life in a new way for today’s ecological crisis, influencing not only the Church but global policies, interfaith dialogue, and grassroots activism.
Contribution by George Lee, RTE