How can there be sins against nature (such as sexual sins) but there can be no such thing as sins against the common home that is the earth?
Seems pretty common sense to me.
Don't worry. After some private discernment you will likely find that your sins against the common home have been committed in ignorance and thus your culpability in them has been lessened. But persisting in them after having learned what they do to God's creation and future generations, or not making efforts to curb them or avoid them, is to put your salvation on the Slippery Slope.
"If the average Catholic reader could be tracked down through the swamps of letters-to-the-editor and other places where he momentarily reveals himself, he would be found to be something of a Manichean." --Flannery O'Connor
If you listen to what Pope Francis is saying and doing you will not go astray.
