Most people view the increase in discarded trash and litter on our beaches and in the oceans as a huge concern. I agree. However, when one seeks solutions to problems, we should always be concerned about unintended consequences of whatever policy it is that we espouse. Banning of plastic bags might, at first, seem to be a reasonable solution – but let’s look at consequences of that decision.
From http://www.allaboutbags.ca/papervplasticstudies.html : “Every bag has an environmental impact. There are no silver bullets. Decisions that are made in the name of the environment must be based on science and fact, not emotion and misconception.”
Fiction: Many believe that paper bags are more environmentally friendly than plastic bags because they are made from a renewable resource, can biodegrade, and are recyclable.
Fact: Scientific research - Life Cycle Assessments - show that the opposite is true. “Plastic shopping bags outperform paper bags environmentally – on manufacturing, on reuse, and on solid waste volume and generation.”
Plastic bags have a much lower carbon footprint. Manufacturing of plastic bags is less resource-intensive and has lower global warming potential because the environmental impacts of supermarket carry bags are dominated by the energy and raw materials needed to produce them. Small amounts of energy and raw materials are needed to make plastic bags, which makes them easier on the environment.
A Scottish study shows that “a paper bag has a more adverse impact than a plastic bag for most environmental issues. Areas where paper bags score particularly badly include water consumption, atmospheric acidification (which can have effects on human health, sensitive ecosystems, forest decline and acidification of lakes) and eutrophication* of water bodies (which can lead to growth of algae and depletion of oxygen).”
Paper bags are between six to ten times heavier than lightweight plastic bags and, as such, require more transport and its associated costs. They would also take up more room in a landfill if they were not recycled.
The UK Environmental Agency performed a life cycle assessment comparing the environmental impact of paper vs plastic grocery bags. The main conclusion was paper bags would have to be used three times to lower their global warming potential to match that of a conventional HDPE plastic shopping bag being used just once. And there are many other studies showing similar results – but be careful of reading studies sponsored by the paper industry, the plastics industry or any other entity with a vested outcome interest.
So, let’s be sure that we consider all impacts when making a decision on paper vs plastic, and especially on banning plastic bags. One should evaluate and compare cradle to grave impacts of alternatives, not merely just a portion of the life cycle. Let’s consider science in making environmental decisions, science that can point the way to holistic considerations between alternatives. Littering is a behavioral issue and is an increasing problem – but banning plastic bags in favor of paper bags results in the total environmental negative consequence increasing owing to the unfriendly environmental footprint of paper bags.