Read our COVID-19 research and news.

Pope Francis

Pope Francis

European Union 2014 - European Parliament

Pope doesn't shy away from specifics in leaked climate encyclical

Pope Francis squarely blames the burning of fossil fuels for climate change in the leaked draft of his long-awaited environmental encyclical posted online by an Italian magazine. But contrary to some earlier predictions, the pontiff also delves into the scientific details of global warming and weighs in on specific policy ideas for curbing emissions.

The Vatican has decried early release of the document, but has not challenged its authenticity. Officials in Rome have made clear they will continue on their planned course of releasing the final document on Thursday, named Laudato si (“Praised Be," after a song to nature written by St. Francis, the pope's namesake). 

The leak—a highly unusual occurrence for a papal encyclical—demonstrates the outsized significance the letter has taken on, coming in the months leading up to key international climate change negotiations in Paris later this year. Indeed, in the draft document, the pope makes clear that he is speaking not only to Roman Catholics, the largest denomination in Christianity with 1.2 billion members throughout the world. Pope Francis said his words are addressed to all people, much as his predecessor, Pope John XXIII, made a similar universal call to humanity in his 1963 encyclical, Peace on Earth, which came as the world faced the risk of nuclear war.

In preparation for the encyclical, the Vatican made a point to gather input from scientists from around the world. A special workshop on "Sustainable Humanity, Sustainable Nature," was hosted in spring 2014 by a little-known but prestigious group of scientists, the Pontifical Academy of Sciences. Members of the nonsectarian academy of 80 scientists, which includes several Nobel laureates, receive lifetime appointments from the Vatican, but do not take direction from the church.

Participants agreed on a statement pointing out the disruption caused by fossil fuel use and calling for cooperative, collective action to curb greenhouse gas emissions.

Prior to release of the draft, speculation was rife on whether the pope, who was trained as a chemist, would delve into scientific and policy details. Samuel Gregg, research director of the Acton Institute for the Study of Religion and Liberty, a conservative Grand Rapids, Michigan–based Catholic think tank, predicted in an interview with The Daily Climate website earlier this year that the pope would steer clear. The encyclical draft, however, indicates quite the contrary; that the pope has opted to incorporate specifics on science and action. For example, he includes a passage that is critical of issuing tradable "carbon credits" as a policy solution.

The draft appears to be “well thought out and well informed by the science advisers on the Pontifical Academy, contrary to statements I have seen publicly that state that he should stick to matters of religion and morals,” says earth scientist Marcia McNutt, a participant in the Vatican workshop and editor-in-chief of the Science family of journals (publisher of ScienceInsider). “He views this as a matter for the church on account of the disproportional impact of climate change on the poor and disadvantaged, which does indeed make it a moral issue.”

In his draft encyclical, which is in Italian, the pope indicates he has absorbed many of the details of the reports of the Intergovernmental Panel on Climate Change. There is "a very consistent scientific consensus indicating that we are in the presence of a disturbing heating of the climate system,” the draft states. “It is true that there are other factors (such as volcanism, the changes in the orbit and the axis of the Earth, the solar cycle), but numerous scientific studies indicate that most of the global warming in recent decades is due to the large concentration of greenhouse gases (carbon dioxide, methane, nitrogen oxide and others) mainly emitted due to human activity.”

The pope adds that there are damaging health effects, particularly for the poor, from fossil fuel pollution. He talks about the damage to ecosystems from soil and water acidification and links it all to a "culture of waste." In one of his more intriguing passages on biological systems, he notes that humanity has failed to realize that "operation of natural ecosystems is exemplary," in that their processing of organic waste gives rise to a new generation of plants.

"In contrast, the industrial system, at the end of its cycle of production and consumption, has not developed the ability to absorb and reuse waste and slag," he writes in the draft. "We have not yet succeeded in adopting a circular pattern of production which ensures resources for all and for the future generations, and which requires us to limit the use of non-renewable resources, to moderate consumption, to maximize the efficiency of the exploitation, to reuse and to recycle."

The pope is scheduled to speak in September to the U.S. Congress, where Catholics account for 31% of members, according to the Pew Research Center on Religion and Public Life.