Millions of plastic shopping bags end up in landfills or as litter every year. Plastic bags can pose a serious threat to wildlife if disposed of improperly, and do not biodegrade in landfills. While both paper and plastic bags have advantages and disadvantages, reusable shopping bags offer a better solution for the environment. San Francisco and Oakland, California, as well as Portland, Oregon and numerous towns and villages in Alaska have now banned plastic shopping bags.
In response to a growing trend to reduce the use of plastic shopping bags, everyone who attended Berkeley's All Associate's Day in September 2008 received a reusable shopping bag with Berkeley's Project GreenPath logo.