The Welsh Assembly Government has said it wants to bring in a compulsory charge on all plastic bags given out to shoppers.
Environment minister Jane Davidson said the evidence from charging schemes brought in by Marks & Spencer and in other countries around the world shows that it reduces use.
She was speaking after the publication of a study looking at the implications of charging for carrier bags.
The study, by environmental consultancy AEA Technology, found the Republic of Ireland had achieved significant reductions in plastic bag usage and littering since introducing a change in 2001.
In the UK, Ikea and Marks & Spencer have reduced bag use by between 80 and 90 per cent since introducing charges.
The study also questioned moves to promote high density polyethylene (HDPE) degradable bags, which have chemical additives added to make them degrade quicker. It said conditions in landfill or elsewhere, 'might not be conducive to reliable degradation'.
Mrs Davidson said she wanted charging to be 'the norm' in Wales.
'In countries as diverse as China, Japan through to Finland, Iceland and Italy some form of charge is the norm.
'I have always said I am an evidence-based minister and this report backs up my view that introducing a charge on single-use carrier bags is the only way to further reduce the amount of single use carrier bags we use in Wales whilst also encouraging people to re-use bags.
'This is about changing consumer habits for the long term good of our environment.