Billions of plastic bags end up as litter every year, instead of being properly disposed of in landfills or recycled. Scattered through cities, seas, forests and fields, these bags become a hazard for wildlife, which become entangled in the bags. Birds that become entangled in plastic may strangle themselves or become unable to fly. Plastic bags are particularly destructive in the marine environment. In addition to entanglement, many sea creatures mistake the bags for food, causing high levels of mortality as the animals cannot digest the bags. Estimates of yearly marine animal mortality due to plastic bags ranges into the millions.
According to the Algalita Marine Research Foundation, the north Pacific Ocean contains six times as much plastic as zooplankton. Most of this plastic has broken down into particulate form, and comes from plastic bags that have blown into the ocean. As a result, creatures that normally feed on plankton are frequently consuming plastic instead. The introduction of plastic into the food chain poisons aquatic life and disrupts reproductive cycles. Due to bioaccumulation and direct ingestion by fish, plastic is increasingly present in fish consumed by humans.
Polyethylene is derived from natural gas and petroleum. Approximately 100 million barrels of oil are needed each year to produce plastic bags. Production of plastic bags results in significant pollution during the drilling and transport process. Moreover, the use of fossil fuels results in tons of carbon and methane emissions, enhancing the greenhouse effect and exacerbating global warming. The global production of plastic bags produces emissions equivalent to more than a million cars each year.
In the United States, only 2 percent of plastic bags are recycled. More than a million birds die each year due to pollution from plastic bags. Even when plastic bags break down, the plastic remains in the environment in the form of small toxic particles. The state of California spends $25 million dollars each year to manage plastic bag pollution. U.S. residents use an average of 1,200 plastic bags per year per person.