We try to be environmentally cautious in our decision making. We’ve seen the commercials of beaches coated in plastic bottles. We know plastic straws hurt turtles and plastic six-pack rings choke everything. All those things are true. However, our commitment to the environment can’t stop at switching our plastic bottles for glass bottles and calling it a day. Unfortunately, that’s partially because a new study indicates glass bottles might be worse.
The Environmental Impact of Bottles, Cartons, Etc
Ian Williams is a Professor of Applied Environmental Science at the University of Southampton. Working with Ph.D. candidate Alice Brock, they compared the environmental impact of different types of containers. The containers they examined were “glass bottles, aluminium cans, milk cartons, Tetra Pak, polyethylene terephthalate (PET) bottles and high-density polythene (HDPE) bottle.”
The pair wrote two versions of their article. The first was published in Detritus, which bills itself as a “multidisciplinary journal for waste resources and residue.” This article was where they looked at the full scope of beverage containers, including milk cartons and juice boxes.
The other article was published in The Conversation, “an independent source of news and views, from the academic and research community,” which grants “access to independent, high-quality, authenticated, explanatory journalism.” This article compared only five options for pop containers. (1, 2)
The Ranking For Glass Bottles
Out of the five containers compared, glass bottles came in dead last.
How is this possible? Well, the answer is not what you might think. Rather than looking at what happens to your bottle after you’re done drinking, it’s how it’s actually produced and brought into stores that’s the problem. (1)
The Production of Glass Bottles
Firstly, the production of glass requires “materials such as silica sand and dolomite, and that can release pollution.” If that’s not bad enough, inhaling small fragments of silica and other materials can contribute to silicosis, a lung condition.
However, that’s not the end of it. To melt these raw materials into glass takes extreme heat, “a process,” the article states, “overwhelmingly powered by fossil fuels.” When the glass is being heated into actually being glass, it also releases carbon dioxide into the air. (1)
The Weight of Glass Bottles
“A one-litre glass bottle can weigh up to 800g,” say Williams and Brock. “A similar plastic bottle weighs around 40g. That extra weight means vehicles transporting glass bottles consume more fossil fuels to deliver.”
Therefore, glass bottles have a 95% greater impact on global warming than using aluminum cans. (1)
What About Recycled Glass?
Recycled glass bottles actually came in fourth. The authors acknowledge that “some energy is saved in recycling rather than extracting, processing and transporting raw materials.”
Still, there are terrible results from burning the materials to form new glass.
“In the UK,” they say, “the recycling rate for glass is 67.6%. This would need to improve for glass bottle production to be self-sufficient by recycling alone.” (1)
So, Is Glass Really Worse Than Plastic?
Yes, in terms of overall impact. However, even though plastic is in third place, according to the researchers, there’s a caveat. “Glass and aluminum don’t break up into harmful microparticles like plastic does.” (1)
