There is an interesting study by the U.K. Environment Agency that challenges the view of banning plastic bags is clearly better for the environment. Sometimes green measures can have hidden carbon costs or negative externalities. The study suggests that a cotton reusable bag commonly used for groceries must be used at least 131 times to overcome their costs and be a net positive for the environment. Los Angeles recently added its name to the list of cities banning free polypropylene bags. Customers must pay 10 cents a bag or bring a reusable bag.
Conversely, a polypropylene bag must be used 11 times to overcome their costs, though that would seem unlikely. Yet, many of the reusable bags are made in China or Vietnam and subject to fuel costs and pollution in transporting them to customers. They are “energy intensive materials” to manufacture.
I still see the value of limiting single use bags which have adverse effects for marine ecosystems, solid waste management, global resource consumption and litter. Only 5 percent of these bags are recycled. Paper bags of course result in huge use of trees that can be avoided with reusable bags.
While I love the convenience of plastic bags, I have been trying to limit my use of the bags. The important thing about this study, however, should not be ignored. Sometimes green measures can be satisfying but actually can raise environmental costs.