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NZ society loathes injustice. Do you? I believe a major injustice is being meted out to one of our most practical objects. The so-called single-use plastic bag has been much maligned recently. The two big supermarket chains have effectively banned their use (whilst retaining the plastic coverings on most of their food – including fresh vegetables). Have you ever tried eating a cling-wrapped cob of corn?

Why is the simple plastic bag so despised?

TurtleThe major claim to hit the headlines recently is the way in which the plastic bag is polluting our vital-for-life oceans and marine life. Plastic is definitely causing havoc and endangering some of our most beautiful and loved creatures. Who doesn’t cringe at the sight of a television or YouTube video showing a dead or maimed dolphin wrapped in plastic or with its intestines crammed with the same? However I would put it to you that this is not the fault of the plastic bag per se. This is the absolute responsibility and fault of lazy, inconsiderate and downright callous human beings. We all know that we should not litter beaches and countryside but look at the evidence. We do.

The motor car supposedly causes injury and death to hundreds of people in our country every year. Do we ban the car? Of course not! We build better roads and try to educate the people responsible in better driving habits.

Supermarket BagsBut what of sustainability and the effect of these bags on our sensitive environment? Let’s take the major options for just supermarket shopping: plastic, paper, cotton and jute and see how they compare.

The revered paper bag is often just a one or two use item simply because of its structure and its certainty to collapse when wet. But wait a moment – paper bags are biodegradable. Sorry folks, in our landfills paper doesn’t degrade because, as Dorte Wray, EO of Wellington’s Zero Waste, said in this very morning’s DomPost, “Landfill is pushed tightly together; no air gets in so compostable waste can’t break down”. Making paper releases four times as much water, and three times as many greenhouse gas emissions as the manufacture of plastic. It takes five times the landfill space. And costs a lot more to produce.

Viewpoint does not allow time to discuss all the bags. Details of the environmental factors of each type of bag may be found at this link.  

So from a carbon and energy point of view, single-use bags are not necessarily bad – it depends how meticulous you are about reusing any of the others. The real problem with plastic is its negligible value (so people discard it without a thought).

Environmentally, we need to educate and enforce better behaviour around littering to stop plastic doing so much harm.

In conclusion, I ask, “Let’s give the humble plastic bag another chance.”

Main References:

Paper, Plastic, or Jute: what’s best for shopping bags? Professor Mike Ashby, winner of the 2017 Sir Alan Cottrell Gold Medal.

Much Maligned

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