Plastic bags are made from polyethylene. Polyethylene is a man made polymer chain of ethylene, which is derived fromnatural gas and petroleum. Both natural gas and petroleum(crude oil) are fossil fuels that are not renewable in any reasonable amount of time(most scientists believe that from living organism to oil or natural gas may take hundreds of thousands or even millions of years; click here and here for a general overview). In it’s simple form, petroleum and natural gas cause enough problems. Oil has been a major source for political conflict(Blood Oil, Junger, Vanity Fair 2007; Oil and Politics, Hanke, CATO Istitute, 2004). Environmentally speaking, the processes for extracting oil and natural gas are some of the most destructive practices we humans are involved in to date(Alberta Oil Sands; Waste discharges during the offshore oil and gas activity), not to mention the miss-handling of these practices(BP Gulf Oil Spill).
When converted to plastic bags a whole new set of problems arise. Plastic bags are polluters of many of the worlds pristine parks, cultural centers, and vast oceans, causing harm to delicate ecosystems and eventually ending up in the stomachs of many different species(The Worlds Largest Dump: The Great Pacific Garbage Patch, Discover Magazine 2008; The Great Pacific Garbage Patch, Santa Barbara News Press 2002). Conventional polyethylene plastic bags do not biodegrade(there are biodegradable plastic bags that are starting to gain some steam such as Bio Bag), however they do photo-degrade, breaking down into tiny toxic particles which can be even more harmful to the environment(Plastics ‘poisoning world’s seas’, BBC News 2006).
It is easy to see why we want to provide a sustainable alternative to plastic.