Pope Francis has declared September 1st, as an annual day of prayer, penance and thanksgiving for creation.
In his Treatise on the Love of God, St Francis de Sales wrote in Book, 2, Chapter 2:

God spoke but one word, and in virtue of that in a moment were made the sun, moon and that innumerable multitude of stars, with their differences in brightness, motion and influence. He spoke and they were made. A single word of God’s filled the air with birds, and the sea with fishes, made spring from the earth all the plants and all the beasts we see. For although the sacred historian, accommodating himself to our fashion of understanding, recounts that God often repeated that omnipotent word: Let there be: according to the days of the world’s creation, nevertheless, properly speaking, this word was singularly one; so that David terms it a breathing or spirit of the divine mouth; that is, one single act of his infinite will, which so powerfully spreads its virtue over the variety of created things, that it makes us conceive this act as if it were multiplied and diversified into as many differences as there are in these effects, though in reality it is most simply and singularly one. Thus S. Chrysostom remarks that what Moses said in many words describing the creation of the world, the glorious S. John expressed in a single word, saying that by the word, that is by that eternal word who is the Son of God, all things were made.