Pope Francis on Thursday urged the world to act quickly to prevent “extraordinary” climate change from destroying the planet and said wealthy countries must bear 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 for the critical situation “Our Sister, mother Earth” now finds itself in.

Newly elected Pope Francis I, formerly Cardinal Jorge Mario Bergoglio, Archbishop of Buenos Aires.

“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 his long-anticipated Encyclical on the environment.

Arguing that environmental damage is intimately linked to global inequality, he goes on to say that doomsday predictions can no longer be dismissed and that: “The earth, our home, is beginning to look more and more like an immense pile of filth.”

Green activists hailed the charismatic Argentinian pontiff’s widely-trailed intervention as a potential game-changer in the debate over what causes global warming and how to reverse it. “Everyone, whether religious or secular, can and must respond to this clarion call for bold urgent action,”said Kumi Naido, the International Executive Director of Greenpeace.

Environmentalists hope the pope’s message will significantly increase the pressure for binding restrictions on carbon emissions to be agreed at global talks in Paris at the end of this year. But even before the official publication, climate change sceptics had dismissed the document’s argument that the phenomenon is primarily man-made and that humanity can reverse it through lifestyle changes including an early phasing-out of fossil fuels.

“I don’t get economic policy from my bishops or my cardinal or my pope,” US presidential candidate Jeb Bush said on the eve of the release in comments that underlined the depth of opposition in the United States to a binding agreement to curb greenhouse gases.