When you compare plastic and cotton bags against each other, it seems that cotton bags are, in fact, less sustainable. Making cotton bags requires more material and more energy than a plastic shopping bag. However, you should consider how often cotton bags and plastic bags are used. Cotton bags are made from a renewable resource and are biodegradable. They're also tough and durable, so they can be reused multiple times.
Hand bags, whether made of jute or cotton, are much stronger and resistant to breakage compared to flimsy plastic bags. They can withstand heavy loads and therefore last longer, which is a great advantage when it comes to sustainability. After all, longevity and quality are key points in the sustainability game. The energy contained in plastic bags initially comes from the extraction of the raw materials needed to convert them into natural gas and oil, whose extraction requires a lot of energy. The plastic bag produced 50.5 grams of sulfur oxides compared to 579 grams in the paper bag; and 45.4 grams of nitrogen oxides, compared to 264 grams in the paper.
While today most fabric bags made of cotton are called handbags, the original bag is made of jute fiber, a natural fiber that is biodegradable and renewable, and which proves to be much more sustainable compared to conventional cotton (we'll talk about this later). However, the issue of microplastics and their impact on our food chain could be more problematic, in addition to the fact that textile recycling is easier to do than the normal recycling of plastic bags (behavioral impacts)). Regarding the choice of bags, Steve Cohen, director of the Research Program on Sustainability Policy and Management at the Earth Institute, said that it is very difficult to predict whether plastic, paper or cloth bags are the best in terms of net energy or carbon, because they all use carbon. Therefore, a fairer comparison between cotton and LDPE bags would be the environmental impact of 7100 LDPE shopping bags versus a reusable cotton bag (this is simplified and, for a truly adequate comparison, different numbers would have to be used).
It's understandable that, during this time of COVID-19, you've turned to plastic bags for protection and are likely to discard them after using them only once. While some countries have taken steps to reduce the consumption of plastic bags, the statistics are still quite good discouraging. You should use paper because that's what the article said was best or maybe just reusing plastic bags, it's not difficult. Non-woven polypropylene fabric-like plastic bags that are often given away as advertising are stronger and more durable than HDPE and LDPE plastic bags and can therefore be used multiple times.
Cotton bags have become a means for brands, retailers and supermarkets to convey a mindset that respects the planet or, at least, to demonstrate that companies are aware of the excessive use of plastic in packaging. In fact, single-use plastic is the best, since it is necessary to use any other type of bag more than 50 times to equalize the amount of damage in production and recycling, if any country recycles instead of burning or burying it, like Malaysia, after the carbon footprint of sending it there. But because they're lightweight and easy to carry, plastic bags are difficult to dispose of properly. Plastic bags produced 7 kg of municipal solid waste, compared to 33.9 kg for paper, and greenhouse gas emissions were equivalent to 0.04 tons of CO2, compared to 0.08 tons for paper.
