Plastic bags are from the same source as all plastic: crude oil. Like everything else manufactured from this non-renewable resource, it has two major drawbacks: manufacturing it emits considerable amounts of pollution, and the product is not biodegradable. In other words, it is difficult to produce, and nearly impossible to get rid of once produced. According to the Natural Environment website, 60 to 100 million barrels of oil are required to manufacture a year’s worth of plastic bags worldwide, and it takes approximately 400 years at least for a bag to biodegrade.