Charges for Single Use Carrier Bags

In an effort to reduce the environmental impact of 'single use carrier bags' the Welsh Government has introduced a law which requires all retailers to levy a minimum charge of 5p for the supply of each bag.

Just when I am contemplating a similar charge for thoughtless/demanding customers who ask for a carrier. I shall be telling them I'm not mean, I'm green. 5p at least in the charity box. Some will get carriers FOC still, but most should pay.