Tuesday, September 4th, 2012

“Paper or Plastic?” “Plastic Please; It’s Greener.” “What?!”

It’s a fact: Plastic shopping bags are greener than paper bags. It’s because they have less impact on the environment. But say that to checkout clerks — or almost anyone else — and they will likely think that you meant to say paper but misspoke, or that you are misinformed, or something worse.

The common assumption that a paper bag is greener than a plastic one is a myth, a false belief, but shared by many who can’t

be bothered with facts. Proving the myth false is done with Life Cycle Analysis (LCA), which totals all of a product’s material and energy inputs and environmental releases from the raw materials used to make it to its end-of-life disposal.

Scientific and comprehensive, LCA can prove difficult to explain briefly and simply, which is why the video below, a TED Talk by Leyla Acaroglu, caught the attention of the American Progressive Bag Alliance.

Acaroglu, the founder and director of Eco Innovators, a consultancy in Melbourne, Australia, is a proponent of systemic Life Cycle Analysis for informed decision-making on strategic sustainability. She is an engaging and easily understood speaker, and as it happens, the title of her six-minute TED Talk is “Paper or Plastic? Debunking an Environmental Myth.”

Her method is a listener-friendly explanation of Life Cycle Analysis applied to the paper vs. plastic bag issue. “Question what you think you know,” she says, about the relative enviro-friendliness of plastic and paper grocery bags. Though she shows that the plastic bag is actually greener, the myth of the paper bag continues because most people won’t take the time to see the full picture of the bags’ environmental impacts.

If you are not familiar with TED Talks, they are presented at three very popular annual TED (technology, entertainment, design) conferences aimed at challenging conventional wisdom by showcasing “ideas that matter” and that spark thought-provoking discussions. Saying the subjects are interesting, widely varied, and surprising is a major understatement.

One note: Although Leyla Acaroglu’s myth-busting explanation of the LCA analysis of paper and plastic bags is excellent, near its conclusion she supports the myth that reusable shopping bags are better for the environment. A study by the UK’s Environmental Agency determined that a cotton bag must be reused at least 131 times to be greener than a plastic grocery bag, and that on average they are reused only 52 times. Plus they need regular hot water washing (think water and energy) to prevent bacterial contamination that can spread serious food-borne illnesses.

That said, Acaroglu’s advice to question what you think you know about grocery bags and her explanation of Life Cycle Analysis are both valid, and form an effective antidote to the mindless repetition of an erroneous myth.

For another quick overview of Life Cycle Analysis, you can download the Life Cycle Analysis Primer put together by the Bioplastics Council, a special interest group of SPI: The Plastics Industry Trade Association. It is not limited to bioplastics and it’s free.

2 Responses to ““Paper or Plastic?” “Plastic Please; It’s Greener.” “What?!””

  1. THe only thing worse than paper is the reuseable bag. In order for them to be sanitary (As in no food contaminents like e coli, etc), they would have to be cleaned/sanitized after each use. People don’t even wash themselves everyday, so why would they wash the dirty reuseable bags.

    You know who those people are: you’ve seen them plopping these filthy, scummy bags onto the checkout counter at the store….eeeww, I don’t even want to put my groceries on the counter after their dirty bags.

    The worst was an exterminator show where they kicked a pile of reuseables and cockroaches came out of them.

  2. The health impacts related to reusable bags (bacteria buildup and potential cross contamination of food items and that the reusable bag can be a carrier for contagious viruses) must be mitigated by regular washing of reusable bags. As a result the recurring consumption of water, electricity, natural gas, and recurring generation of greenhouse gases by consumers to sanitize the bags, was not accounted for in the original life cycle assessment. Hence, the reusable bag is not at all friendly to the environment. The plastic bag still wins hands down as having the lowest impact to the environment.

    80% of plastic debris in the worlds ocean comes from land bases sources and conveyed to the ocean via the storm drains and rivers. Installing trash screens on storm drains that empty into the river or ocean allows all trash including plastic bags to be captured and disposed of. Litter control measures such as this one will help reduce the impact to the environment from litter. The predominant form of litter is fast food litter and eliminating plastic bags won’t address this. Aggressive litter control is required.

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