We are leaving in a world that generates 17,000 plastics bottles per second. This means a million bottles per minute or, roughly, half a trillion bottles in 2021 or 62 plastic bottles / cap/ year. We have just started to realize that plastics are so successful as materials that even if we want we can’t get rid of them without a substantial economic, social and technological cost. We are living in a plastic matrix and we have to understand that plastic pollution becomes gradually integrated to our ecosystems, in many different forms.
Recently more than 20 countries have come forward to support the #CleanSeas campaign, which calls on governments, industry and citizens to end the excessive, wasteful usage of single-use plastic and eliminate microplastics in cosmetics, both major sources of marine litter, by the year 2022.
Worldwide, more than 40 countries have already introduced plastic bags bans of special taxes. Governments all over the world have acted to ban the sale of lightweight bags, charge customers for lightweight bags and/or generate taxes from the stores who sell them. The Bangladesh government was the first to do so in 2002, imposing a total ban on the bag. Such a ban has also been applied in countries such as Rwanda, China, Taiwan, and Macedonia. Some countries in Western Europe impose a fee per bag. Bans, partial bans, and fees have been enacted by some local jurisdictions in North America, Australia, and Myanmar.
Last month, Kenya put in place a rule that will punish anyone making, selling or importing plastic bags with as much as four years in jail or a $19,000 fine.
I think there is a need to make a Reality Check. Are bans and taxes in single use plastics, and especially plastic bags, an effective measure and in what terms?
There is no doubt that bans reduce immediately single use plastic littering. As an example, in San Jose, California, a plastic bag ban led to an 89 percent reduction in the number of plastic bags winding up in the city’s storm drains. A plastic bag tax levied in Ireland in 2002 has reportedly led to a 95 percent reduction in plastic bag litter there.
After implementing the new plastic bag ban, San Francisco reportedly saved up to $100,000 for avoided plastic bag cleanup costs and a total of $600,000 in savings from reducing single-use plastic bags waste processing fees.
Regarding the effectiveness of taxes, a recent example comes from the UK where the introduction just over two years ago of a 5p charge on single-use plastic bags led to an 85% reduction in their use inside six months. Washington, DC’s government estimates that its 5-cent bag tax has led to a 60 percent reduction in the number of these bags being used, although that figure is contested by other sources.
There is no doubt that bans reduce immediately clogging and littering – but regarding climate change things are more complicated
In Rwanda, traffickers caught carrying illegal plastic are liable to be fined, jailed or forced to make public confessions. The nation’s zero tolerance policy toward plastic bags appears to be paying off: Streets in the capital, Kigali, and elsewhere across this hilly, densely populated country are virtually spotless.
There is no doubt for the direct and immediate positive contribution of the bans and taxes to reducing problems like:
- Clogging waterways
- Littering cities and natural parks
- Marine litter
- Ingestion of plastics by animals and introduction of plastics to the food chain
However, things are less clear when we are talking about the carbon footprint. In this case, the major question is what substitutes plastic bags. Are plastic bags substituted by reusable bags or by single use paper bags? For how many times the reusable bags are still usable? Are they made from virgin or recyclable plastics? The paper bags are made from local recyclable paper or they are made from paper produced by cutting virgin forests? To answer such difficult questions, we have a tool named life-cycle assessment – the problem is that its use is not always easy due to the vast amount of information required and the assumptions involved.
The problem becomes more complicated because there are many available studies with conflicting results and some of them are sponsored by the plastic industry – obviously, the industry has a lot of reasons to stop, modify or delay bans and taxes. I would prefer to deal with studies made without any intervention by the plastic industry, so let’s see some of them in brief.
A famous and certainly very comprehensive study that was implemented by an Australian state environmental agency concluded that paper bags have a higher carbon footprint than plastic. That’s primarily because more energy is required to produce and transport paper bags. Another recent study concluded that plastic bag has lesser environmental impact compared to paper bag based on global warming potential, acidification, human toxicity impact, and photochemical ozone creation categories.
Despite the popular belief that paper bags are better, the truth is different. David Tyler, a professor of chemistry at the University of Oregon who has examined the research on the environmental impact of bag use, explains that “People look at paper and say it’s degradable, therefore it’s much better for the environment, but it’s not in terms of climate change impact. The reasons for paper’s higher carbon footprint are complex, but can mostly be understood as stemming from the fact that paper bags are much thicker than plastic bags. Very broadly, carbon footprints are proportional to mass of an object. For example, because paper bags take up so much more space, more trucks are needed to ship paper bags to a store than to ship plastic bags”.
Another interesting study focused on the Life Cycle Assessment of Reusable and Single-use Plastic Bags in California. It concluded that reusable plastic bags can reduce the amount of greenhouse gas emissions, solid waste generation, and acid rain pollution than single-use polyethylene plastic bags. The plastic bag with the least amount of environmental impacts would have the following features:
- Made from recycled plastics, and
- Lightest weight possible.
People look at paper and say it’s degradable, therefore it’s much better for the environment, but it’s not in terms of climate change impact
Instead of conclusions, I would like to finish with the study made by the U.K. Government Environment Agency “A Life Cycle Assessment of Supermarket Carrier Bags”. I think it is very useful because it allows us to think in a broader way and get the full picture. This study concluded that:
- The environmental impact of all types of carry bags is dominated by the resource use and production stages. Transport, secondary packaging and end-of-life management generally have minimal influence on their performance.
- Heavier, sturdier bags of all materials have a higher global warming potential. For example, the production of cotton with its heavy pesticide and water use has a negative impact on the environmental benefit of cotton bags.
- Whatever type of bag is used, the key to reducing the impacts is to reuse it as many times as possible.
- The reuse of conventional HDPE and other lightweight carrier bags for shopping and/or as bin-liners is pivotal to their environmental performance, and reuse of bags as kitchen catchers produces greater benefits than recycling bags. The study identified that 40.3% of plastic bags were reused as bin liners in the UK.
To recap, the positive impact of bans and taxes to plastic bags to littering, clogging, marine litter and food chain protection are obvious and there is no doubt about them. But when we talk about their whole life cycle climate change impact, things are different and more complicated. From this point of view, banning plastic bags and putting taxes on them makes sense only and when we can replace them with reusable bags that are produced without serious environmental impacts. In many studies, the best case seems to be a reusable bag from recyclable plastics. But still, as the UK study concluded the environmental impact of all types of carry bags is dominated by the resource use and production stages and not by their end-of-life management.
In any case, bans and taxes to single use plastics will be more useful if they serve as a starting point towards broader waste prevention policies. And talking about waste prevention we should think more the content of the bags than the bags themselves. If we buy less and more responsibly, if we can avoid overconsumption and Black Fridays, if we can reduce food waste and meat consumption we will create a much better environmental impact. If we continue to consume and waste as we do today, no ban or tax will be useful…