Caritas in veritate, starting with paragraph 48, discusses our relationship to the natural environment.
Also, his message for the celebration of the World Day of Peace 1/1/08 beginning about paragraph 7 might be useful.
Thank you, clockwise! Just what I was looking for. I knew one of our knowledgeable FReepers would come through!
I was going to suggest Caritas in Veritate emphasizing the subsidiarity.
Start with yourself
Then your family
Then your neighborhood
Then your city
Then your county
Then your state
Then your nation
Then the world
Then the Church’s views on it all.