China has announced a ban on the production, sale and use of ultra-thin plastic bags. Shoppers around the country will also now have to pay for regular plastic bags. According to estimates from the Chinese Plastics Processing Industry Association, one billion bags had been given out by supermarkets every day, while two billion are used for other purposes. The Daily Green suggests that this policy might save up to 37 million barrels of oil a year.

The ban, which had been announced in January, is not without precedent in China and around the world. The city of Lijang, in China’s Yunnan province, banned the bags five years ago, with some success. Ireland, Bangladesh and Rwanda have already implemented similar measures on a national level and there are a number of positive local examples of towns and districts, including Modbury in the UK, cleaning up their acts.

Reuters reported that in some supermarkets, where plastic bags had been considered an essential part of the shopping experience in a country new to mass-consumption, bag consumption was down by 90%. The Beijing Evening News reported that authorities in Beijing fined a shop 10,000 yuan ($1,200) for secretly using ultra-thin bags.

The move is another example of positive environmental action by Chinese central government. However, as with previous attempts to curb pollution, there remain questions about the ability and willingness of local government to enforce the will of the center.

The Times in London ran a somewhat skeptical piece, suggesting that it was almost impossible to see any immediate effect in Beijing. But, in Lijang, local officials note that they have achieved a reduction over a much longer period of time. In an article on chinadialogue earlier this year, head of the Gucheng environmental protection bureau in Yunnan province, Zhang Wei, noted that, ‘Nowadays, if you walk around Lijiang carrying a plastic bag, people will look down on you. The plastic bag has something of a pariah status’. Ultimately policies like this require a transformation of social norms, government regulation is useful, but to achieve real change people must also take it upon themselves to set their own positive example.