Robert (name changed to protect the guilty) always double-bags the groceries at the store where I shop.
Paper or plastic doesn't make any difference to him, it is always a 2 for 1 bagging extravaganza.
I generally bring my own bags, but on the rare days when I forget, I always tell Robert to single-bag my items. The consternation on his face is significant, and I can tell he doesn't like me throwing off his system.
Sure, heavy loads need to be double-bagged, but most trips to the store don't require doubling for every purchase. It's wasteful and unnecessary.
It is probably safe to assume Robert fills a minimum 100 bags of groceries a day, placing them in 200 actual bags when doubled. If he works five days a week that's an extra 500 bags he has dispensed. Give him 50 weeks of work a year and Robert has sent roughly 25,000 additional bags out the door because of his propensity for doubling up. It takes an awful lot of individual recycling to make up for the work habits of just one Robert.
Every organization has a Robert (or several of them) ... the individual whose personal practices accumulate to subtly undermine a larger organizational commitment or emphasis. It's great that your organization cares about XXX, but not if with every action taken your Robert negates what you might be trying to accomplish.
Being clear on your desired results is only step one. Getting all of your Roberts in line is where the hard work actually begins.