Pope Francis' highly anticipated encyclical letter on ecological issues will state that global climate change is "mainly" due to human activity, a person familiar with the document has said.
The encyclical, to be released Thursday, will reportedly say that while there are both natural and human causes to climate change "great natural forces are not under our control; human causes are."
"There is strong scientific evidence that the human factors are already having much impact and causing great damage not only to nature itself but also to the lives of people across the globe, especially the poor," said the source, who asked not to be identified because of the sensitivity surrounding the launch of the document.
"Accordingly, it is morally imperative that we human beings take responsibility for what we are doing, act to slow down and reverse the trends, and make every effort to prevent further damage," the person said.
"This requires a change of heart and establishing new ways of producing, distributing and consuming, in order to take better care of our common home and its inhabitants," they said.
Francis' encyclical, to be titled "Laudato Si', On the care of the common home," has attracted wide attention for its expected stances on a number of issues -- from climate change, to global mining practices, to wider Catholic theological notions of ecology.
The person familiar with the document said that a "great novelty" in its writing "is that it comes from a shepherd who’s thinking of all those who are his." Francis, the person said, "has a big overview, the capacity of helping us walk towards a more integral ecology that is all inclusive and comprehensive."
The source also said that the encyclical would call all to action on ecological issues and that, after reading it, no person would be able to say the pope had spoken only to a certain side of the issues.
Summarizing the overall argument of the text, the person said the letter could be boiled down to one statement: "Gated communities are over. Not because someone is pushing down the gate, but because people are saying we cannot go on living like this."
The encyclical letter is to be released at noontime in Rome Thursday in various languages.
The Vatican is also hosting a press conference that morning launching the document, with Cardinal Peter Turkson, president of the Pontifical Council for Justice and Peace; Orthodox Christian Metropolitan John of Pergamon, a noted theologian; and John Schnellnhuber, the director of the Potsdam Institute for Climate Impact Research.
The phrase "Laudato Si’" is taken from the original Umbrian-Italian prayer of 13th century St. Francis Assisi, commonly known as the Canticle of the Creatures. The phrase reoccurs several times as the prayer praises God first by thanking God for such creations as "Brother Fire" and "Sister Water."
"Be praised, my Lord, through all Your creatures, especially through my lord Brother Sun," St. Francis wrote in the third stanza of the prayer. He then continued, expressing praise to God for "Sister Moon," "Brothers Wind and Air," "Sister Water," "Brother Fire, and "Mother Earth."