Pope Francis letter on climate change leaked: Draft Vatican encyclical released three days early

The letter has been regarded as a calm to arms to tackle climate change

Pope Francis greets the crowd from the central loggia of St Peters' basilica after the "Urbi et Orbi" blessing for Rome and the world following the Easter Mass in Vatican

The draft of a much-anticipated encyclical on climate change by Pope Francis has been leaked to an Italian newspaper.

The momentous letter from the Pope to Catholic churches on "the care of the common home" was sent to Italian magazine L'Espresso, three days after it was intended to be published

Over 200 pages, Pope Francis builds on concern for the environment expressed by previous Popes, and preaches that humans have used the Earth irresponsibly and have become detached from the planet.

Citing a similarly pivotal encyclical by Pope John XXIII during the Cold War urging for peace, Pope Francis addresses "every person who lives on this planet" to engage with the issue of climate change.

"Climate change [...] constitutes one of the main current challenges for humanity," Pope Francis warns.

In a segment characteristic of his concern for the poor, the Holy See goes on to argue that developing countries will bear the brunt of the resulting issues which were caused by "the enormous consumption of some rich countries."

Pope Franics also stresses that the destruction of the environment is wrong not only because God entrusted us with the Earth, but because human life itself must be protected through lifestyle changes.

The document - which is the first Pope Francis has written - features six chapters and two prayers. It will be presented to a press conference by Cardinal Peter Turkson, head of the Vatican’s Pontifical Council for Justice and Peace, Metropolitan John Zizioulas of the Orthodox Church, and - most controversially - Hans Joachim Schellnhuber, a professor at the Potsdam Institute for Climate Impact Research, according to The Sunday Times.

An encyclical is the highest level of teaching document a Pope can issue, and could therefore see the world's 1.2billion Catholics adopt greener lifestyles.

It comes after the Pope declared last year that he intends to tackle climate change in 2015, and it is widely regarded as an attempt to influence the UN talks in Paris later this year.

Highlighting the importance of the draft letter, a Vatican official told Bloomberg that the release was a "heinous act."