QUESTION: Once and for all, I’d like the answer: paper or plastic? Asked by Jerry Adler from New York, N.Y.
ANSWER: In actor Ben Stiller’s comedic masterpiece Zoolander, male model Derek Zoolander bursts onto the fashion runway featuring an outfit for his new series Derelict. Composed of billowing black plastic bags and candy wrappers, the outfit is, as Zoolander would say, “Really ridiculously good-looking.”
Well, yes Derek, this outfit may be “so hot right now,” but are plastic bags really the most sustainable choice for this outfit? Wouldn’t a paper bag gown be better for the environment, because after all, paper is biodegradable, right? Maybe. But like beauty itself, the answer to the classic “paper versus plastic” question is more than skin deep. Whether you’re designing a new green fashion piece or simply buying some groceries, we need to break it down and figure out which bag product is more sustainable. It’s a bag-off, people!
Plastic grocery bags came onto the scene in the 1950s and exploded in popularity—in the U.S. alone we use around 100 billion per year. They are made from natural gas and byproducts from the petroleum refining process. It is estimated that it takes the equivalent of around 12 million barrels of oil to create the annual U.S. supply of plastic bags. That’s a bit less than what the Unites States uses daily for transportation. The bags are produced (pdf) by extruding molten plastic into thin sheets. The lightweight satchels are then bundled up by the thousand and transported across the country and around the world to distributors who typically hand them out for free with purchases.
This is where things get messy. After being used, most of the bags go to the landfill, where they linger indefinitely. (Plastic bags can be recycled but just five percents actually are recycled in the United States. This SAGE answer explains why.
Many plastic bags end up littering parking lots and the sides of freeways, clogging sewer lines, and generally making a nuisance of themselves. And they often blow or flow into the ocean and other bodies of water. Traditional plastics do not biodegrade or revert into environmentally benign molecules. Instead, they photodegrade, breaking down into smaller and smaller pieces of plastic until billions of individual plastic molecules are all that remain. Around 4 billion plastic bags become litter worldwide every year, and they can wreak havoc on marine ecosystems by entangling and choking organisms that encounter them. A recent global cleanup effort removed 1.37 million plastic bags from coastal areas in a single day.
So, surely paper bags are better? My male model friends tell me that brown is the new green. Unfortunately, making paper is pretty awful for the environment, too. It takes around a gallon of water per bag to filter and clean the pulverized cellulose fibers of a felled tree to create flawless brown paper. Around 14 million trees a year are chopped down to make brown paper bags. Certainly recycled paper fiber can be used in this process, but the actual percentage of reused fiber in the bags varies widely by supplier and location. Once manufactured, paper bags are bigger and heavier than plastic ones and take significantly more energy to transport. A plus for paper bags is that if they do become litter they will biodegrade, but ironically, if they are sent to the landfill they won’t likely break down due to the lack of oxygen, water and microbial activity. However, brown paper bags can be effectively recycled to make products such as cardboard, and approximately 20 percent of paper grocery bags are recycled in the United States each year.
Clearly, both paper and plastic bags have serious environmental impacts. And that makes the winner to this epic bag-off equally clear: reusable bags. True, you have to remember to bring your canvas or woven-plastic tote bag, but if you do, you can easily side step the negative environmental impacts of single-use paper and plastic bags. If you drive, simply keep them in the trunk. Can’t remember to bring your reusable bags when you’re going to the store? Get a pocket-sized, U.S.A.-manufactured Chico bag and tuck it in your purse or clip it to your belt! Maybe Derek Zoolander’s Derelict style will catch on and people will someday wear reusable tote bag gowns to the grocery store.
For more on the big question of whether we should be using single-use plastics in the first place, and a plan to make Stanford’s campus plastic-bag free, follow along to the Nitty-gritty answer.
A solid, user-friendly overview of Life Cycle Assessment thinking. Consumers often get caught up in the more visual impacts of these products (e.g. the Pacific Garbage Patch). But it’s important to consider their impacts throughout the life cycle (resource extraction and sourcing, production, use, and disposal/reuse) and on a variety of environmental systems (water, GHG emissions, land use, natural resources, air quality, etc). So many variables and assumptions come into play that it can really be difficult to compare the products and determine which option is truly “best.” Great job explaining that dilemma.
One concern I have with the article is that this assessment process is not applied to reusable bags. I assume they require even more intense inputs than paper bags. Therefore, we’d have to use them for longer to offset the additional environmental impacts. How many times would we have to use a reusable bag in order to “breakeven”? Again, diversity in production processes really complicates this type of calculation, but the point is that reusable bags are not the straightforward solution the article suggests. There is a trade off. I too believe that reusable bags are ultimately the proper action, but I’d love to see the data to back it up.
Thanks for helping get people to think more deeply about these issues!