VATICAN CITY (AFP) - Pope Francis on Thursday issued a global plea for action to prevent "extraordinary" climate change from destroying the planet and said wealthy countries must bear primary responsibility for creating the problem and for solving it.
In a radically worded letter addressed to every person on the planet, the leader of the world's 1.2 billion Catholics blames human greed and self-destructive enthralment to new technologies and progress for the critical situation "Our Sister, mother Earth" now finds itself in.
"This sister now cries out to us because of the harm we have inflicted on her by our irresponsible use and abuse of the goods with which God has endowed her," he writes in one of the opening passages of his long-anticipated Encyclical on the environment.
Green activists have hailed the charismatic Argentinian pontiff's widely-trailed intervention as a potential game-changer in the debate over what causes global warming and what can be done to reverse it.
They hope it will significantly increase the pressure for far-reaching measures to be agreed when more than 200 countries gather in Paris for a December summit aimed at clinching a global accord on carbon emissions.
But even before the official publication, climate change sceptics had dismissed the document's arguments that the phenomenon is primarily man-made and that fossil fuels must be phased out.
"I don't get economic policy from my bishops or my cardinal or my pope," United States presidential candidate Jeb Bush said on the eve of the release in comments that underlined the depth of opposition in the US to a binding global agreement to curb greenhouse gases.
The Encyclical references the arguments of the sceptics by acknowledging that volcanic activity, variation in the earth's movements and the solar cycle are factors in climate change.
But it maintains that "most global warming in recent decades is due to the great concentration of greenhouse gases released mainly as a result of human activity".
And it leaves no doubt that the pope believes the world is on a fast-track to disaster.
"If present trends continue, this century may well witness extraordinary climate change and an unprecedented destruction of ecosystems, with serious consequences for all of us," he writes.
Conflict and war
Those consequences, he argues, will include a rise in sea levels that will directly threaten the quarter of the world's population that lives near or on coastlines, and will be felt most acutely by developing countries.
Highlighting warnings that acute water shortages could arise within decades, he writes that, "the control of water by large multinational business may become a major source of conflict in this century".
He adds: "It is foreseeable that, once certain resources have been depleted, the scene will be set for new wars."
One of the recurring themes in the encyclical is that rich countries must accept responsibility for having caused climate change and should "help pay this debt" by cutting their carbon emissions and helping the developing world adopt sustainable forms of energy generation.
"The land of the southern poor is rich and mostly unpolluted, yet access to ownership of goods and resources for meeting vital needs is inhibited by a system of commercial relations and ownership which is structurally perverse," the pope writes in perhaps the most radical passage of the document.
He said the world had to stop burning fossil fuels.
"We know that technology based on the use of highly polluting fossil fuels - especially coal, but also oil and, to a lesser degree, gas - needs to be progressively replaced without delay," he writes.
Developing countries will need financial help to do this "but to do so they require the help of countries which have experienced great growth at the cost of the ongoing pollution of the planet".
This pact, he says, needs to be incorporated into binding accords.
"Enforceable international agreements are urgently needed, since local authorities are not always capable of effective intervention."