These cardinals will likely consider the climate when casting votes for the next pope

And Pope Francis elevated ecological concerns to new heights, through major teaching documents (Laudato Si', Laudate Deum, Querida Amazonia) and calls for a united effort across the globe to end the fossil fuel era and limit suffering and destruction from climate change.

With that prelude, the upcoming conclave to select the next pope will include a number of cardinals who have been outspoken and action-oriented in their own right on environmental issues, including climate change, both locally and on the international stage.

Below is a (non-exhaustive) review of some of the leading cardinals at the intersection of faith, ecology and climate.

Cardinal Luis Antonio Tagle
Pro-Prefect, Vatican Dicastery for the Evangelization of Peoples; appointed cardinal by Pope Benedict XVI in 2012

Like numerous Filipino bishops, Tagle, 67, is outspoken on environmental issues, especially the disproportionate impact of storms strengthened by climate change on poor and marginalized communities. He has preached about ecological sin and endorsed international climate action. While president of Caritas Internationalis, the church's official international aid organization divested its finances from the fossil fuel sector. A key ally of Francis on integral ecology, he is one of four cardinals on the advisory council of the Laudato Si' Movement.

"The poor are suffering greatly from the climate crisis and fossil fuels are among the main drivers of this injustice." —Cardinal Luis Antonio Tagle, on Caritas' 2018 fossil fuel divestment

Cardinal Michael Czerny
Prefect, Vatican Dicastery for Promoting Integral Human Development; elevated to cardinal by Pope Francis in 2019

As head of the Vatican's justice, peace and creation care hub, the Canadian Jesuit has played a central role in bringing Francis' encyclical "Laudato Si', on Care for Our Common Home" from prayer to action. Czerny, 78, has overseen the rollout of the Laudato Si' Action Platform, served as a special secretary at the 2019 synod on the Amazon and supported an international Fossil Fuel Non-Proliferation Treaty. With often frank and forceful speeches, Czerny has emphasized the connections among Francis' three encyclicals — Laudato Si', Fratelli Tutti and Dilexit Nos — and championed sustainable development while criticizing a "technocratic paradigm" that sees technology alone as capable of solving world problems.

"We are at a critical historical moment where actions today will determine the fate of generations to come. The challenge ahead is monumental; we need nothing short of a 'bold cultural revolution' to respond to it adequately." —Cardinal Michael Czerny at the 2023 release of an environmental science booklet for Catholics

Cardinal Peter Turkson
Chancellor, Pontifical Academies of Sciences and Social Sciences; elevated to cardinal by Pope John Paul II in 2003

Turkson, 76, was among the drafters of Laudato Si', and his role as head of the Vatican's peace and justice congregation (now the Dicastery for Promoting Integral Human Development) had him globetrotting to spread its message: at U.N. climate talks, Davos, universities and more. He delivered a "10 principles of Laudato Si'" document to diplomats at the COP21 climate summit that produced the Paris Agreement. The Ghanaian cardinal oversaw the development of the Laudato Si' Action Platform, and in his current role at the pontifical science academies continues to hold conferences on environmental topics, including a 2024 gathering of governors and mayors on the topic of climate resilience.

"This may well be the most important challenge of the 21st century. It calls for global dialogue and leadership. It is a moral issue of the highest order. No country can tackle this problem alone, nor can the poorer ones without much help." —Cardinal Peter Turkson in 2015 speech at Boston College on Laudato Si' and forthcoming negotiations on the Paris Agreement on climate change

Cardinal Fridolin Ambongo Besungu
Archbishop of Kinshasa of the Democratic Republic of Congo; elevated to cardinal by Pope Francis in 2019

A Capuchin Francisan, Ambongo Besungu, 65, has emerged as one of the leading prelates on environmental issues in Africa. As president of the Symposium of Episcopal Conferences of Africa and Madagascar, he has denounced extraction of the continent's natural resources by multinational companies and tied climate justice to land justice. A member of Francis' Council of Cardinals, he has advocated for Indigenous rights, endorsed agroecology practices and wealthy nations to support the Global South in climate solutions.

"Wherever you look on this continent, a continent already struggling due to an unjust global economic system, you see climate change holding back the potential for development." —Cardinal Fridolin Ambongo Besungu ahead of the 2022 U.N. climate summit in Sharm el-Sheikh, Egypt, which the cardinal attended

Cardinal John Ribat
Archbishop of Port Moresby, Papua New Guinea; elevated to cardinal by Francis in 2016

Archbishop of a South Pacific island, Ribat, 68, has witnessed the impacts of climate change up close, with his archdiocese helping resettle climate refugees from the Carteret Islands fleeing rising seas. He has stressed the unequal impacts of climate change upon poor and young people with limited resources to flee storms or rebuild. Ribat, a member of the Laudato Si' Movement advisory council, has opposed deep seabed mining in the Pacific over concerns it damages undersea ecosystems and disturbs fishing grounds.

"The difference between 1.5C and 2C of warming is the difference between prosperity and poverty, life and death, protecting 'the least of these' and ignoring their pleas for help. … The good news is that primary solution to the climate crisis is clear: we must stop using fossil fuels, and we must do it as quickly as we can." —Cardinal John Ribat in a 2018 op-ed for the U.K.-based Catholic Herald

Cardinal Jean-Claude Hollerich
Archbishop of Luxembourg; elevated to cardinal by Francis in 2019

Head of the Catholic Church in the tiny European state, Hollerich as president of the Commission of the Bishops' Conferences of the European Union joined a bishops' statement to the 2018 U.N. climate conference urging world leaders "make rapid and radical changes" to avert devastating climate impacts. A fellow Jesuit and member of Francis' Council of Cardinals, Hollerich has been outspoken of the role of finance in facilitating the use of fossil fuels. In November 2020, his Luxembourg Diocese and the EU bishops' commission committed to abstain from fossil fuel investments, and has encouraged young Catholics to write to their bishops about climate change and fossil fuel divestment.

"We are co-responsible for this earth, there is only one. We have to act now and I think the urgency of this call is very important." —Cardinal Jean-Claude Hollerich

Cardinal Malcolm Ranjith 
Archbishop of Colombo, Sri Lanka; elevated to cardinal by Pope Benedict XVI in 2010

Ranjith, 77, has been a vocal local environmental defender in his south Asia country, calling pollution the worst cancer afflicting the world today. In 2021, he raised alarm about the transfer of a portion of the Muthurajawela wetland to private companies, and sued a ship owner for alleged toxic chemical dumping into the sea off Sri Lanka's coast. Ranjith has urged the Sri Lankan government to end deforestation and to adopt renewable energy. 

"It has been proven with evidence that [coal power plants] pose threats not only to the environment but to the lives of the people." —Cardinal Malcolm Ranjith at a 2020 press conference calling for the closure of Sri Lanka's coal-fired power plants

The Americans

The Catholic cardinals of the United States have been among the country's most engaged prelates in acting on Francis' calls in Laudato Si'.

Cardinal Robert McElroy, 71, archbishop of Washington, D.C., elevated 2022 by Francis: Outspoken on the moral questions of climate change, McElroy led the first U.S. diocese (San Diego) to publicly divest from fossil fuels and encouraged solar energy in parishes. He has advocated the U.S. bishops create a permanent Laudato Si' committee and participated in the Amazon synod.

Cardinal Blase Cupich, 76, archbishop of Chicago, elevated 2016 by Francis: Cupich has emphasized the need for ecological conversion in areas of spirituality, education and economics and criticized libertarianism as a roadblock to U.S. reception of Laudato Si'. His Chicago Archdiocese created a Laudato Si' commission and purchases renewable energy certificates to cover the electricity demands of its 2,000-plus buildings.

Cardinal Wilton Gregory, 77, retired Washington archbishop, elevated 2020 by Francis: Seen as an early U.S. Laudato Si' leader, Gregory while Atlanta archbishop commissioned a Laudato Si' action plan for parishes, schools and Catholics, which has been widely adopted across U.S. dioceses.

Cardinal Joseph Tobin, 72, archbishop of Newark, elevated 2016 by Francis: Tobin has called on countries to mitigate climate impacts and also develop and share adaptation and recovery resources. As Indianapolis archbishop, he created a creation care commission, and in Newark commissioned a Laudato Si' action plan.

Cardinal Timothy Dolan, 75, archbishop of New York, elevated 2012 by Benedict XVI: Dolan formed an energy management department in the New York Archdiocese to assist parishes and schools in energy upgrades. He encouraged Catholic participation in the 2014 Global Climate March.