When Pope Francis's encyclical letter Laudato Si' came out, I was a bit befuddled by the media coverage, which claimed that the pope had suddenly become an environmentalist, and also wrote about the poor, with a sprinkling of traditional Catholic condemnations of things like artificial birth control. Frankly, it sounded like a pretty schizophrenic document (which, in any case, I didn't have time to read).
But I was again reminded of Laudato Si' when I came across a Financial Times article about Yellowstone that asked, "Are humans part of nature, or above it? Why do we care about setting aside 'wild' lands such as Yellowstone? Why do we care about the survival of wolves in the first place? Does nature and wildlife have intrinsic value?" So I picked up the document and was pleased to discover both insight and coherence.
I've excerpted some passages and will be sharing them a few times a week. Below is the first installment, in which Francis traces some of the origins of his thinking in the work of his predecessors (and implicitly argues that, although the emphasis may be new, the Church's concern for the environment is not).
1. “LAUDATO SI’, mi’ Signore” – “Praise be to you, my Lord”. In the words of this beautiful canticle, Saint Francis of Assisi reminds us that our common home is like a sister with whom we share our life and a beautiful mother who opens her arms to embrace us.…
2. 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. We have come to see ourselves as her lords and masters, entitled to plunder her at will. The violence present in our hearts, wounded by sin, is also reflected in the symptoms of sickness evident in the soil, in the water, in the air and in all forms of life. This is why the earth herself, burdened and laid waste... “groans in travail” (Rom 8:22). We have forgotten that we ourselves are dust of the earth (cf. Gen 2:7)….
Nothing in this world is indifferent to us
3. …Faced as we are with global environmental deterioration, I wish to address every person living on this planet…. I would like to enter into dialogue with all people about our common home.
4. In 1971,… Blessed Pope Paul VI referred to the ecological concern as “a tragic consequence” of unchecked human activity: “Due to an ill-considered exploitation of nature, humanity runs the risk of destroying it and becoming in turn a victim of this degradation”. He... stressed “the urgent need for a radical change in the conduct of humanity”, inasmuch as “the most extraordinary scientific advances, the most amazing technical abilities, the most astonishing economic growth, unless they are accompanied by authentic social and moral progress, will definitively turn against man”.
5. Saint John Paul II became increasingly concerned about this issue. In his first Encyclical he warned that human beings frequently seem “to see no other meaning in their natural environment than what serves for immediate use and consumption”.… At the same time, he noted that little effort had been made to “safeguard the moral conditions for an authentic human ecology”. The destruction of the human environment is extremely serious, not only because God has entrusted the world to us men and women, but because human life is itself a gift which must be defended from various forms of debasement. Every effort to protect and improve our world entails profound changes in “lifestyles, models of production and consumption, and the established structures of power which today govern societies”. Authentic human development has a moral character. It presumes full respect for the human person, but it must also be concerned for the world around us and “take into account the nature of each being and of its mutual connection in an ordered system”.…
6. My predecessor Benedict XVI likewise proposed “eliminating the structural causes of the dysfunctions of the world economy and correcting models of growth which have proved incapable of ensuring respect for the environment”. He observed that the world cannot be analyzed by isolating only one of its aspects, since “the book of nature is one and indivisible”, and includes the environment, life, sexuality, the family, social relations, and so forth. It follows that “the deterioration of nature is closely connected to the culture which shapes human coexistence”. Pope Benedict asked us to recognize that the natural environment has been gravely damaged by our irresponsible behaviour. The social environment has also suffered damage. Both are ultimately due to the same evil: the notion that there are no indisputable truths to guide our lives, and hence human freedom is limitless. We have forgotten that “…man does not create himself…”. With paternal concern, Benedict urged us to realize that creation is harmed “where we ourselves have the final word, where everything is simply our property and we use it for ourselves alone. The misuse of creation begins when we no longer recognize any higher instance than ourselves…”.
 Canticle of the Creatures, in Francis of Assisi: Early Documents, vol. 1, New York / London /Manila, 1999, 113-114.
 Apostolic Letter Octogesima Adveniens (14 May 1971), 21.
 Address to FAO on the 25th Anniversary of its Institution (16 November 1970), 4.
 Encyclical Letter Redemptor Hominis (4 March 1979), 15.
 Encyclical Letter Centesimus Annus (1 May 1991), 38.
 Ibid., 58.
 Encyclical Letter Sollicitudo Rei Socialis (30 December 1987), 34.
 Address to the Diplomatic Corps Accredited to the Holy See (8 January 2007).
 Encyclical Letter Caritas in Veritate (29 June 2009), 51.
 Address to the Bundestag, Berlin (22 September 2011).
 Address to the Clergy of the Diocese of Bolzano-Bressanone (6 August 2008).