Plastics Bags

Plastic bags and plastic bottles - CO₂ emissions during their lifetime Plastic is in every part of our daily lives. Since plastics are derived from oil, they have a definite carbon footprint associated with them. Different plastice have different overall footprints. Depending on the level of reuse, a plastic bottle may have a much lower footprint than a plastic bag of the same weight. On the other hand, littering is perhaps the severest problem related to plastic bags.

The carbon footprint of plastic (LDPE or PET, poyethylene) is about 6 kg CO₂ per kg of plastic. If you know the weight of your plastic bags, you can multiply it with the number of plastic bags you are consuming per year. Then you can calculate the carbon dioxide emitted by your own usage of plastic bags. See below for some background information.

• The production of 1 kg of polyethylene (PET or LDPE), requires the equivalent of 2 kg of oil for energy and raw material. Polyethylene PE ist the most commonly used plastic for plastic bags.
• Burning 1 kg of oil creates about 3 kg of carbon dioxide. In other words: Per kg of plastic, about 6 kg carbon dioxide is created during production and incineration. 
• A plastic bag has a weight in the range of about 8 g to 60 g depending on size and thickness. For the further calculation, it now depends on which weight for a plastic bag you actually use. A common plastic carrying bag in our household had a weight between 25 g and 40 g. So I took the average of 32.5 g.
• Take the above relation between kg plastics and kg of carbon dioxide, and you get about 200 g of carbon dioxide for 32.5 g of plastic, which is the equivalent of the average plastic carrying bag for groceries. Or in other words: For 5 plastic bags you get 1 kg of CO₂.

Of course you'll find different figures on the Internet. The main factors are the weight of the plastic bag and whether the grey energy (energy used for production and disposal) is taken into account.

Some Additional Facts on Plastic Bags
Plastic bags:

• Each person on average uses 83 bags a year.
• 500 billion (500,000,000,000) plastic bags are manufactured each year.
• 100 billion plastic bags are used in the United States alone.
• Over 1 million plastic bags are being used every minute worldwide.
• Release toxins into the ground water from landfill sites.
• Stay in the environment for hundreds of years while they break down - up to 1,000 years.
• Get into the food chain through animals that ingest small particles of plastic.
• Waste energy during the manufacturing process.
• Kill an estimated 100,000 marine animals each year.

 For more information on recycling your plastic bags, click the following link - PlasticBagRecycling.org.