Short Answer: Plastic bags became popularized in the early 1980s because plastic was stronger than paper bags while remaining lightweight, durable, and cheap. Currently 100 billion plastic bags are used annually in the U.S.
Long Answer: Plastic shopping bags are ubiquitous. An average family will consume
60 plastic bags over the course of 4 trips to the grocery store (1).
Yet, plastic bags are a relatively new invention. The earliest were
manufactured in 1950s, but it wasn't until the 1960s that the modern
shopping bag was designed by Sten Gustaf Thulin (2). The Swedish
engineer developed the simplified design, allowing a single tube of
plastic to be folded and processed into a lightweight, durable bag. The
patent was registered with Celloplast in 1965, though it was overturned
in 1977 when U.S. based petrochemical company Mobil challenged it. The
Dixie Bag Company then brought the plastic bag to shopping centers,
first Kroger grocery stores in 1982 and then Safeway soon after. With
it's high load capacity, it was stronger than the traditional paper bag
while remaining lightweight.
Plastic
bags negatively impact the environment. They are a large part of
litter, resulting in issues ranging from aesthetic displeasure to
flooding due to clogged sewers (2). Annually, 10% of plastic produced
will end up in an ocean, which harms wildlife by detracting from habitat
suitability, strangling animals, and
causing gastrointestinal complications when ingested (2, 4). It's estimated that 100,000 sea turtle and other marine wildlife will die each year due to plastic bags (5). Because plastic is extremely durable, it takes a long time to decompose without human intervention (around 1,000 years) (1).
In addition to these negative traits, plastic bags are convenient leading to their continued use. Bags are cheap: retailers spend $4 billion on plastic bags ($4 billion/ 100 billion bags = $0.04/bag) (5). Because many retailers don't charge for the plastic bags, that cost is
instead passed on to consumers through raised prices. The Wall Street
Journal reported that Target, the second largest retailer in the U. S.,
consumes 1.8 billion plastic bags annually (5). More generally, plastic bags are used at a rate of 1
million plastic per minute in the U.S. (1).
Most bags today are made of
polyethylene, a product of natural gas
and petroleum. Recycling
plastic bags can be an issue. Curb based recycling programs, often
feeding single stream systems, can't take the bags even though more
rigid plastic of the same material is accepted. This is because of the bag's
lightweight. Bags can cause issues by jamming machinery or being falsely
identified as paper and causing issues with pulp at later steps (2).
While there are some biodegradable bags available, they
haven't been widely adopted and don't solve the issues of plastic bags.
Biodegradable bags can't decompose in closed landfills, defeating
the purpose of using biodegradable bags over plastic. They can also
cause issues with current plastic bag recycling programs. If
biodegradable bags are mixed in with plastic bags during the recycling
process, this can contaminate the product and cause problems with
machinery (2).
However, five states and the District of Columbia have legislation
requiring retailers to have convenient storefront recycling programs for
bags in an effort to increase recycling (3). Two
states have banned plastic bags altogether: California and Hawaii.
California was the first state to ban plastic bags statewide in 2014,
but the law was placed on hold until it passed a referendum in November
2016 (3). The law prohibits retailers from using plastic bags and
requiring a minimum charge of 10 cents for recycled paper bags (3). Yet a
proposition put forth at the same time to put the 10 cent charge into
an environmental fund didn't pass (3).
Hawaii has
banned plastic bags throughout the state, but did it on a county by
county basis. The first counties banned the bags in 2011 with the final
county banning bags in 2015 (3, 4). The Hawaii ban also included the ban
of paper bags containing less than 40% recycled materials (4).
In
contrast, three states have enacted legislation preventing
municipalities and counties from enacting plastic bag bans or taxes
(3).
“Between 2015 and 2016 at least 77 bills have been proposed by 23 states
regarding the regulation of plastic bags in retail settings. Only three
states—Arizona, Idaho, and Missouri—have enacted legislation this year,
all of which preempt local governments from regulating the sale or use
of plastic bags, including the imposition of any fees or taxes” (3)
So what can you as an individual do?
1. Stop using plastic bags and opt for using your own reusable bags. Some retailers will give you a discount if you do.
2. Take whatever plastic bags you do have to a recycling center or calling your local waste management facility about whether they'll accept plastic bags into their recycling center.
3. Pick up plastic bag litter when you encounter it outside.
4. Contact your local representatives and ask if measures for banning or taxing plastic bags are
a) in place
b) proposed and being voted on
c) need a champion to introduce into the legislature
***Remember: while only 2 states have legislation banning plastic bags statewide, there are many more cities and counties that have their own bag measures curtailing plastic bags. Don't forget your city representatives when you're checking in with your politicians!
5. Encourage your family and friends to reduce their use of plastic bags. This works especially well if you're able to model such behavior for them rather than just tell them.
Sound off in the comments if this sparks more questions!
(1) Statistic Brain. Sept. 4, 2016. (Accessed Jan 3, 2017).
(2) Wikipedia. "Plastic Shopping Bag". (Accessed Jan 3, 2017).
(3) National Conference of State Legislation. "State Plastic and Paper Bag Legislation". (Accessed Jan 3, 2017).
(4) Carla Herreria, Huffington Post. July 1, 2015. "Hawaii Just Became the First State to Ban Plastic Bags at Grocery Checkouts". (Accessed Jan 3, 2017).
(
5) Rensselaer County Legislature. "Plastic Bag Facts" (Accessed Jan 4, 2017).
The above graph was generated using the flow rates of different shower heads and the average capacity for a household tub. 
