Plastic shopping bags are typically made of polyethylene or petroleum based and are not biodegradable. They just sit in landfills that emit harmful greenhouse gases and pollute the oceans killing and harming wildlife. More than 500 billion plastic bags are distributed every year, and only less than 3% of those bags are recycled. Paper shopping bags are just as bad for the environment for the amount of water and materials used for it's production. Grocery chains are not willing to be the first to stop carrying them altogether because they fear in this economy their competitors will have an advantage over them so we need legislation or we need the big grocery chains and stores to come together and sign an agreement to stop providing these "disposable" shopping bags. Whether on not you believe in global warming we can all agree clean air and water is something we all need.