A levy on plastic shopping bags is not a panacea for our environmental woes, but it will be a significant step in the right direction. There is a good chance it will become law later this year if the government sticks to its guns, as it is promising to do. Yet, at this late date, an influential trade group representing major retailers is still arguing that a voluntary scheme would be better than a legally enforceable levy. It seems to want the legislation delayed or even shelved altogether. Overseas, similar levies have proved effective; there is no reason to think it will not work in Hong Kong. The Retail Management Association yesterday announced that from March, 2,000 outlets run by major member chains would not offer plastic bags to customers unless they asked for them. Among these are major supermarket chains, drugstores and convenience shops. Some may also ask shoppers to make small donations to green causes in return for a bag. This is, in effect, an extension of the 'No Plastic Bag Day' already in force once a week at some supermarkets. It is good to see the industry taking the initiative to help raise people's awareness of environmental issues and reduce waste created by the disposal of plastic bags. The voluntary scheme will certainly help reduce usage before the levy is introduced. But it must not replace it. As a group, leading retailers bear direct responsibility for the hundreds of millions of bags they give out each year. The voluntary scheme goes some way towards meeting this responsibility but does not meet it fully. Even the association acknowledges its scheme will not match the effectiveness of a levy - which is expected to reduce plastic bag usage by a billion a year rather than the 400 million the association estimates for its scheme. It is true such a responsibility does not rest on retailers alone; shoppers must also do their part. Many would rather bring their own, reusable bags than pay a 50 cent levy. People don't like paying - that is exactly why a levy will be effective in reducing plastic bag use. The association says success will attract more member companies to join. But there is also nothing to stop them dropping out. There is no guarantee that the programme would continue if the government agreed to delay or shelve the levy. More than a year ago, ParknShop launched, with much fanfare, a campaign asking customers to pay 20 cents for each plastic bag requested. It lasted less than a week. The levy is but a first step. Plastic bags, though environmentally damaging, take up only small chunks of our landfills, which are filling to capacity. We urgently need comprehensive recycling programmes for different polluting materials. Under the Product Eco-responsibility Bill, other 'producer responsibility' schemes await subsidiary legislation, yet we are still bogged down in the first stage with plastic bags. Discussions have barely started on how to administer product collection, deposit refunds, advance recycling fees and environmental levies for electronics, car tyres, plastic products and other waste materials. Hong Kong needs to develop the kind of waste recycling and reduction laws that will meet people's demands for a better environment.