Pope Francis blames 'human selfishness' for global warming
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 criticised by some US conservatives.
It has been dismissed by two Republican presidential candidates.
Humans to blame
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.
Pope Francis writes that: "We have come to see ourselves as her lords and masters, entitled to plunder her at will.
"The violence present in our hearts, wounded by sin, is also reflected in the symptoms of sickness evident in the soil, in the water, in the air and in all forms of life."
He criticises 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.
Vatican spokesman Federico Lombardi launched the pontiff's second encyclical at a news conference on Thursday.
The teaching is more evidence of a pontiff determined to act as a catalyst for change, and a powerful diplomatic player on the world stage, says the BBC's religious affairs correspondent Caroline Wyatt.
The release comes six months before international leaders gather in Paris to try to seal a deal to reduce carbon emissions.
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.
But a leak of the document, published by Italy's L'Espresso magazine on Tuesday, had a frosty response from sceptical conservatives in America, including two Roman Catholic presidential candidates.
Jeb Bush said he did not get his economic policy from his bishops, cardinals or pope - so why his policy on the environment?
Meanwhile Rick Santorum questioned whether the Pope was credible on the issue of climate science.
US Senator, Jim Inhofe, chairman of the US Senate Environment Committee, said he disagreed with the Pope's "philosophy" on global warming.
"I am concerned that his encyclical will be used by global warming alarmists to advocate for policies that will equate to the largest, most regressive tax increase in our nation's history."
However, many academics have welcomed the pontiff's input.
Prof Myles Allen, Professor of Geosystem Science at the University of Oxford in the UK, said: "If Pope Francis can't speak up for our unborn grandchildren, then God help us all."
Will Pope sway Americans? - Roger Harrabin, BBC News environment analyst
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.
Ms 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.