Pope Francis has blamed human selfishness for global warming in his long-awaited encyclical calling for action on climate change.
In the letter, he urges the rich to change their lifestyles to avert the destruction of the ecosystem.
Environmentalists hope the message will spur on nations ahead of the UN climate conference in Paris in December.
But parts of the document, leaked earlier this week, have already been criticized by some US conservatives.
It has been dismissed by two Republican presidential candidates.
The encyclical, named "Laudato Si (Be Praised), On the Care of Our Common Home", aims to inspire everyone - not just Roman Catholics - to protect the Earth.
The 192-page letter, which is the highest level teaching document a pope can issue, lays much of the blame for global warming on human activities.
He criticizes what he calls a "collective selfishness", but says that there is still time to stop the damage, calling for an end to consumerism and greed.
UN Secretary-General Ban Ki-moon welcomed the document, saying climate change was a "moral issue requiring respectful dialogue with all parts of society".
It has also been widely praised by environmental groups, with WWF president Yolanda Kakabadse saying it "adds a much-needed moral approach'' to the debate on climate change.
Greenpeace leader Kumi Naidoo highlighted passages calling for policies that reduce carbon emissions, including by replacing fossil fuels with renewable energy.
The UN's climate change chief Christiana Figueres says the Pope's message will influence talks in Paris this year on a deal to tackle global warming.
Developing countries are demanding firmer promises of financial help from rich countries so they can adapt to inevitable changes in the climate and get clean energy to avoid contributing to further warming.
Figueres said their position would be strengthened by the Pope's insistence that this was the clear moral responsibility of the rich.
The encyclical will be welcomed by poor countries in Africa and Latin America.
The big question is how it will play in the USA, where it has already been dismissed by a Republican presidential candidate Jeb Bush, who is a Catholic.
Leading Republicans have warned the UN that they will undo President Barack Obama's climate policies - so if the encyclical sways any of the conservative Catholics in Congress that could prove significant.