In the UK we managed to introduce a levy on single use carrier bags in 2015. It has done tremendous amounts of good with, reducing carrier bag usage by 85%. But more needs to be done!
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One obvious place to go is to extend the levy to single use produce bags - the ones you put loose fruit and veg in at the supermarket. It would encourage people to forgo these bags as they now do with carrier bags. There's absolutely nothing wrong with simply placing the loose items straight into the bag for life that people now use daily!
In my job I see people unnecessarily using these bags in ways they would now never do with other carrier bags. This levy would reduce usage and raise money