As for his certainty of the importance of ecology, one of his most important ecological treatises is his January 17, 2001 General Audience, which reads thus:
On the one hand, this vision might represent a lost paradise and, on the other, the promised paradise. Not without reason, the horizon of a paradisal universe, which Genesis (chap. 2) put at the very origins of the world, is placed by Isaiah (chap. 11) and the Book of Revelation (chap. 21-22) at the end of history. Thus we see that man's harmony with his fellow beings, with creation and with God is the plan followed by the Creator. This plan was and is continually upset by human sin, which is inspired by an alternative plan depicted in the same Book of Genesis (chap. 3-11), which describes man's progressive conflictual tension with God, with his fellow human beings and even with nature.
2. The contrast between the two plans emerges clearly in the vocation to which humanity is called, according to the Bible, and in the consequences resulting from its infidelity to this call. The human creature receives a mission to govern creation in order to make all its potential shine. It is a delegation granted at the very origins of creation, when man and woman, who are the "image of God" (Gn 1: 27), receive the order to be fruitful and multiply, to fill the earth and subdue it, and to have dominion over the fish of the sea, the birds of the air and every living thing that moves upon the earth (cf. Gn 1: 28). St Gregory of Nyssa, one of the three great Cappadocian Fathers, commented: "God made man capable of carrying out his role as king of the earth.... Man was created in the image of the One who governs the universe. Everything demonstrates that from the begining his nature was marked by royalty.... He is the living image who participates by his dignity in the perfection of the divine archetype" (De Hominis Opificio, 4: PG 44, 136).