Pope Francis called on the world Thursday to combat global warming to prevent environmental ruin to the Earth.
In a landmark letter, the pontiff supported scientific evidence that climate change is mostly caused by human activity that he said could lead to "an unprecedented destruction of ecosystems" in this century.
He called for an end to what he said is a "culturally perverse" economic system in which the world's wealthiest countries exploit the poorest, leaving the Earth looking "more and more like an immense pile of filth."
Francis said a massive political and economic transformation is needed, to replace "without delay" the world's dependence on highly polluting fossil fuels that lead to climate-changing global warming. He said the world's resources are "being plundered because of shortsighted approaches to the economy, commerce and production."
The pontiff's plea came in a 191-page encyclical aimed directly at the world's 1.2 billion Roman Catholics, but more broadly at world leaders considering a global climate pact later this year at a Paris conference. It was the first such papal environmental statement in the centuries-long history of the church.
Praise and criticism
His statement drew praise from global and environmental leaders but was attacked by conservative Republican presidential candidates in the United States as news of the pope's views leaked in recent days.
President Barack Obama said Thursday that he welcomed the pope's letter and that he deeply admired Francis' decision to "make the case, clearly and powerfully and with the full moral authority of his position," for action.
"We must also protect the world's poor, who have done the least to contribute to this looming crisis and stand to lose the most if we fail to avert it." the president said.
U.N. Secretary-General Ban Ki-moon, who has made ambitious action on climate change one of his signature issues since taking the helm of the United Nations nearly a decade ago, expressed deep thanks to Francis "for taking such a strong stand on the need for urgent global action."
The pontiff's "moral voice is part of a growing chorus of people from all faiths and all sectors of society speaking out for climate action," Ban said. "I urge all governments to place the global common good above national interests and to adopt an ambitious, universal climate agreement in Paris this year.”
The international community will meet in Paris in December with the intention of agreeing on a universal, legally binding climate treaty, the objective of which would be to limit global warming to less than 2 degrees Celsius a year by 2020, when the deal would go into force.
Achim Steiner, chief of the U.N. Environment Program, said the papal statement "is a clarion call that resonates not only with Catholics, but with all of the Earth's peoples. Science and religion are aligned on this matter: The time to act is now."
World Bank President Jim Yong Kim noted that global climate change has led to an increasing number of extreme weather events, which he said are "most devastating" for the world's impoverished people.
"As the effects of climate change worsen," Kim said, "we know that escaping poverty will become even more difficult."
Sierra Club executive director Michael Brune said, "The vision laid out in these teachings serves as an inspiration to everyone across the world who seeks a more just, compassionate and healthy future."
But climate change skeptics dismissed the papal statement, and there is widespread conservative opposition in the U.S. to a binding agreement on pollution standards to limit greenhouse gases.
U.S. Republican presidential candidate Jeb Bush, a convert to Roman Catholicism, rejected the papal statement in advance, saying, "I don't get economic policy from my bishops or my cardinal or my pope."
The Heartland Institute, a U.S. group promoting free-market solutions to global problems, said the pope "made a grave mistake by putting his trust and moral authority behind agenda-driven bureaucrats at the United Nations who have been bearing false witness about the causes and consequences of climate change for decades."
While many conservatives recognize the Earth is warming up, they do not believe human activity is the cause and point to natural fluctuations in the global temperature, which they say has been going on since the planet was born. Some opponents of a global warming treaty say some parts of the Earth have actually cooled off in recent years.
But climate change does not necessarily mean a warmer planet. The more immediate consequences include altered weather patterns and stronger storms that bring floods and higher sea levels to some parts of the world while leaving other areas parched.
Seeking change in lifestyle, production model
In the statement, Francis said, "Humanity is called to recognize the need for change of lifestyle, production, and consumption, in order to combat this warming or at least the human causes which produce or aggravate it." But he said one tactic some environmentalists favor — the use of carbon credits to curb development by some corporations to allow other business activity — is ineffective.
The encyclical, which is the second-highest ranking document a pope can issue, reflects a continuation of relatively progressive stances taken by the Argentina-born pope. He has also called on the church to become more welcoming to homosexuals and to not put undue focus on controversial issues related to abortion and gay marriage.
"A gay person who is seeking God, who is of good will — well, who am I to judge him?" the pope said in 2013 as part of a response to reports of gay clergy members in the Vatican.
The stances are seen as a major shift away from the public positions of Pope Francis' predecessors, and have upset many conservative members of the worldwide church.
VOA's Margaret Besheer contributed to this report from the United Nations.
