A couple of times this week, I put an item in the trash when I could have recycled it. I did not think about it at the time, but tonight for some reason, I did.... and I have concluded that not recycling when you can, has to be a sin. Not a huge sin, but a sin, nonetheless.
The reason why, I think, is because any time you do not do what you know is the right thing--because you are too lazy--cannot possibly be pleasing to God. He knows about and cares about everything that happens on Earth; it is His creation, and because it is His creation--if we love Him--we must love the Earth too.
Actually, anything you do deliberately that is objectively not good, has to be sinful, because you are falling short of the perfection to which those who love God aspire.
When I go to Confession tomorrow, I hope Father Rafael does not laugh at me when I confess that I did not recycle :-)