A popular organic food store in Amsterdam has this sign posted near the entrance:
Marqt accepts all credit or debit cards, free of charge. Thank you for contributing to a safer and cleaner environment.
and in the small print at the bottom:
We cannot accept cash. Thank you for your support.
This claim is repeated more clearly on their web site (HT @Nat):
Even when it comes to the payment method they’ve taken the environment into account; you can only pay with pin, chip or credit card, so keep that in mind when you stop by to buy your groceries! Not using cash really is safer, better for the environment and also faster!
Is there any evidence that the use of credit cards contributes to a "cleaner environment"?