In the intro to Laudato si, Pope Francis' encyclical on the environment, the pope turns his attention to the model of St. Francis and explains why he is a great model for Catholics when it comes to how we look at environmental issues. The heart of St. Francis' for God's creation should be our hearts as well. 

jonnycatholic.wordpress.com

https://www.vatican.va/content/francesco/en/encyclicals/documents/papa-francesco_20150524_enciclica-laudato-si.html