By Callum Burkett
With growing pressure from the the public on their plastic consumption, supermarkets around the country are moving towards a plastic free grocery system. At first glance you might think this is a positive move toward reducing our carbon emissions from large overseas companies with stores in New Zealand, however I am about to shed some light upon the true science and facts behind plastic bags.
Earlier this year over 65,000 people across the country signed a petition to be delivered to parliament demanding a strict ban of the sales and use of plastic bags. Positive moves that show our society has noticed the importance of protecting our environment, however evidence provided by Denmark and England’s Ministry for the Environment, has proven that the true environmental impacts of plastic shopping bags is far less the the public believes it to be.
So does this mean that the government bid to ban these single use bags is ill founded? Well in a comparison to supposedly more environmentally friendly alternatives, a plastic bags environmental impact is equal to that of four uses of a paper bag, five of a thicker LDPE plastic bag, 14 of a non woven polypropylene (the most common alternative provided in supermarkets) and a staggering 173 uses of a woven cotton reusable bag.
What does this mean for us the consumer? Well it potentially means that in trying to do the right thing we have pressured our supermarkets into increasing their environmental impacts. Results from an Australian based research trial, when prices of regular plastic bags increased, the sales of thicker less environmentally friendly plastic bags increased by 31 percent, New Zealand’s research into this topic showed that throughout its life cycle including extraction of natural resources and production, a regular plastic bag had the lowest carbon footprint out of all proposed alternatives, especially when its final stage was that of a household bin liner, as it often is.
The global warming impact is not the only defining figure that determines how environmentally friendly a bag is. Photos of marine life strangled by plastic bags are popular marketing images from corporations along the lines of Greenpeace. Independent studies carried out in the US and Australia showed that plastic bags account for around 1 percent of the litter that ends up in our oceans harming marine animals, the highest products from both studies were cigarette packets, glass bottles, and food containers.
Although banning plastic bags is a positive step towards reduced carbon emissions, realistically it is only a tiny dent in the beast that is climate change.
According to renowned Kiwi scientist Dr Michelle Dickinson what we need is an evidence based study that looks at the behaviors of New Zealanders. To see how and what we use our plastic bags for. The data can then be used to develop an effective strategy to reduce emissions, rather than responding with little effectiveness to quickly comprised studies which are not science based and rather comprise mainly of emotions and perspectives. If we do not, we will only end up exchanging one type of plastic for another less friendly one.