A reusable bag is not itself eco-friendly

Cloth bags, like paper bags or bamboo-knit items, have become trendy and opened up new markets that serve the positive demand of people who are aware of environmental protection and sustainability.

But when these cloth bags, often carrying a brand or sponsor's images, started to fill up my wardrobe, and there were so many of them I could not use or reuse them efficiently, I realized that cloth bags do not automatically mean sustainability.

Using a cloth bag repeatedly is obviously more friendly to the environment than discarding single-use plastic bags.

But a Clemson University's study about the life cycle of shopping bags in the U.S. found that most cloth bags were not recycled enough.

How enough is enough? More than 300 times for a cotton bag, according to the study.

According to another study by the Denmark Ministry of Environment and Food, a cloth bag needs to be reused around 20,000 times or in more over 50 years, to compensate for the energy put into its production – that's really the only way to make it truly "environmentally friendly."

I also understand more about this after studying a subject called Life Cycle Assessment during my masters’ degree course. A product might look green and eco-positive when you use it. But you have to consider the entire life process it has gone through, from the collection of materials it is made of, to the production process, to the moment where it is discarded. This is the only way to estimate whether or not it’s actually green or sustainable.

First of all, the bag fabric takes a lot of resources to produce. Cotton requires a lot of water to grow. To produce enough fiber for a T-shirt, we will need an amount of water equal to the amount an average adult drinks over a full 900-day period. That's over two years of human body water!

Also, there's energy used during the dying, sewing, and transporting processes. Cloth bags that carry patterns made from less degradable PVC are even less green.

It's the same problem with paper bags. They are easily recycled and biodegradable, but the production of a paper bag costs around four times the energy used in a plastic bag. Chemicals used in the production of paper bags are also damaging to the environment.

A National Geographic study showed that a paper bag needs to be reused three to 43 times. But as they are easily torn, it's hard to achieve such repetition.

Every consumer needs to be informed accurately on exactly how "usable/reusable" any bag is, and they need to be instructed as to how such items are best recycled and discarded properly. The most important thing is we should try to maximize the number of times we can use those bags to reduce their impacts on the environment.

Changing consumption habits, with a focus on how we use and reuse things, is a more relevant answer to our trash problem than simply switching from plastic to a material that looks green.

Environment protection requires comprehensive solutions based on scientific data. Blindly following a trend might only create a surplus of different kinds of trash.

I think people should pay attention to what they need to buy and don't, to reduce the waste they generate, and especially refrain from taking on more bags.

For example, instead of leaving bubble tea shop employees to put each cup in a plastic bag, one can ask them to put the cups all together in one bag, or even better, in bags that customers are required to carry from home.

*Trinh Phuong Quan is an architect.