A look at our choices
For many, paper seems to be the obvious choice. It’s recyclable and trees are a renewable resource, but Bob points out some flaws in this logic. “Paper bags, even with 100% recycled content, have significantly higher average impacts on the environment than either reusable bags or lightweight plastic bags,” according to Bob’s Clemson study. And, while paper bags are recyclable, this is only an advantage if consumers actually recycle them. If not, paper bags sit in landfills just like plastic bags, where both will persist for years. Overall, paper bags are responsible for seven times more environmental impact than lightweight plastic bags in comparative use, Bob says. Moreover, we need our mature trees to pull carbon dioxide from the atmosphere.
What about reusable bags? They provide advantages, but there are some caveats. While today’s consumers are more likely to remember to bring reusable bags with them, they must do so many times in order to lower their average negative impacts on the environment versus lightweight plastic bags. Do you know how many times? For non-woven polypropylene bags, each bag must be reused at least 30 times to meet this target. Cloth bags require an astounding 300 times of reuse to make up for their environmental impacts. Additionally, reusable bags pose health risks if they are not properly and regularly cleaned, but nearly 50% of consumers never clean them or do so infrequently, according to the Clemson study.
Lightweight plastic bags, on the other hand, offer several advantages and should not be the villain. For example, they are often reused by consumers, such as for trash, and they make up less than 1% of litter, according to the Clemson study. Additionally, lightweight plastic bags are made from a byproduct of natural gas production, not from imported oil, and natural gas is a plentiful resource in the United States.
Plastic packaging, in general, is essential to the supply chain. “We really can’t do without plastics. Plastic packaging is essential to keep food safe and to help the huge problem of food waste. Plastic packages are lighter than alternatives and they can be made with less total material weight. They result in lower shipping costs and, in particular, lower energy use for transportation,” Bob explains.
There is, however, recognition that not enough is being done to develop plastics that will biodegrade in the ocean. This is not an easy problem since the point of plastic bottles is to keep water in—not be susceptible to it, Bob explains. Some biodegradable plastics are already in commercial use, but that does not mean their overall environmental impact is favorable. The necessary recycling infrastructure is not adequate, and the likely by-products of biodegradation include greenhouse gases such as carbon dioxide and methane. Because of these issues, most scientists believe that biodegradable plastics are a last resort, not a solution.