Plastic bags have a bad reputation and with good reason. It takes centuries for one to dissolve after ending up in a landfill, while paper decomposes much more faster and easily. In fact, according to an article in Slate magazine, plastic bags do not biodegrade at all, so you would have to wait for UV rays to destroy it, which can take anywhere from 500 to 1,000 years or more. Also, the Environmental Protection Agency points out that 12 million barrels of oil are used in the US alone to produce plastic bags.