Oil and natural gas are non-renewable resources. This means they can't be reused, and when they are all gone, they are gone forever. Also, manufacturing these bags adds a lot of pollution to the environment. When you go shopping with a parent, take some paper bags with you. At the check-out counter, ask the clerk to put your groceries in the reused bags.
Some stores offer discounts for people who use their own bags.
For every bag reused, they give money back - usually about five cents for each bag. With your parents, pick a spot in your house to store bags that you get from the grocery store. These bags can be used to carry things to friends' houses or for trash linings. After bags wear out, recycle them. Use notebook paper on both sides.