Plastic grocery bags are simultaneously simple to overlook and difficult to ignore—simple due to their durability, lightness, cost-free nature, and their ability to serve as small refuse bags after groceries are unpacked and their initial purpose is fulfilled; difficult because these problematic items are ubiquitous. When disposed of in landfills, they are carried by the wind, becoming ensnared in power lines, accumulating along sidewalks and in drains, and eventually reaching coastal regions. There, they pollute shorelines and are carried out to sea, ensnaring and asphyxiating marine animals and releasing harmful chemicals into the aquatic environment. Additionally, plastic bags and other plastic debris deter visitors from polluted areas and diminish the value of waterfront properties. Research indicates that plastic waste incurs an annual global cost of $100 billion in harm to marine properties and ecosystems.
Legislators have taken action. Over 100 nations have introduced either partial or complete prohibitions or charges on plastic shopping bags at national or subnational levels. Within the U.S., 611 state or local regulations were put into effect between 2008 and 2023, with the vast majority, 91%, being enacted at the city or township scale.
Are plastic bag bans successful?
What is the efficacy of these measures, particularly in areas where plastic bags cause the most significant damage—namely, coastal regions? A recent study published in Science investigated this query, revealing a positive outcome: very effective—in certain instances, they reduced the quantity of plastic bags littering shorelines by nearly 50%. Given that many environmental initiatives frequently fall short of expectations, controlling plastic bags seems to be a notable ecological triumph.
“I found it surprising to witness the effectiveness of plastic bag policies in decreasing plastic bag litter along shorelines,” stated Kimberly Oremus, an associate professor at the University of Delaware’s School of Marine Science and Policy and co-author of the Science publication. “Although they do not eradicate the issue entirely, they certainly contribute to its reduction. The expanding adoption and geographical reach of these policies within the U.S. instill optimism in me.”
The recent research, spearheaded by environmental economist Anna Papp, an incoming postdoctoral scholar at MIT, analyzed the composition of waste gathered during 45,067 shoreline cleaning efforts from January 2016 to December 2017. It contrasted findings from locations under plastic bag restrictions with those that were not. Jurisdictions with bans or limitations observed a 25% to 47% reduction in bag presence compared to unregulated zones. Furthermore, these areas reported 30% to 37% fewer incidents of animal entanglement.
How do plastic bag bans work?
The bag regulations enacted in the designated “treated” regions fell into one of three categories: complete prohibitions on plastic bags; limited bans allowing sturdier, reusable bags less prone to wind dispersal; and charges—effectively levies—on plastic bags, added to the grocery total at the point of sale. Among these, partial bans proved least successful in reducing plastic bags in coastal litter. Surprisingly, fees demonstrated greater efficacy than outright bans; while the authors lack a conclusive explanation, they offer several hypotheses.
“A potential explanation,” Oremus stated, “is that in certain instances, the revenue generated from fees is allocated towards additional litter reduction efforts. Another theory is that plastic bag fees are enforced across a broader range of retailers compared to plastic bag bans. Many complete bans also incorporate exceptions for specific retailers or bag varieties, such as permitting plastic takeout bags from restaurants for hygiene purposes. Our ultimate theory suggests that fees might achieve greater adherence rates than a complete ban.”
Outcomes within different jurisdictions are not isolated. The researchers observed both negative and positive ripple effects between locations. Some regulated areas still accumulated bags carried by wind from unregulated districts, while certain unregulated places appeared slightly cleaner if they bordered a regulated community. Overall, achieving broader consistency across a wider geographical area is better accomplished through statewide prohibitions instead of fragmented county or township restrictions.
“Statewide regulations encompass the most significant number of individuals and cleanup operations within our study period,” Papp noted. “The strength of their impact likely stems from their more extensive geographical reach, which reduces issues associated with spillovers, like consumers transporting plastic bags from unrestricted to regulated zones.”
What more can be done to reduce plastic waste?
Papp and Oremus emphasize the ongoing necessity for plastic limitations not solely within the U.S., but globally. A report from the Organization for Economic Cooperation and Development (OECD), cited in their research, revealed that certain regions of Africa possess 12 times more uncollected or improperly managed plastic waste than the U.S., all of which requires regulation or removal. To address this, Papp and Oremus indicate that 175 nations are currently negotiating to establish the first international plastics agreement. The urgency for such an accord is considerable. Annually, more than 460 million metric tons of plastics are manufactured worldwide, according to the International Union for the Conservation of Nature, with over 20 million metric tons discarded into the environment. This waste volume is projected to triple by 2060.
“Plastic bags represent merely one form of numerous plastic pollutants in the environment,” Papp stated, “thus, bag regulations are clearly not an exhaustive remedy. More encompassing approaches that target the manufacturing or provision of plastics are probably required.”