There are a lot of decisions that you need to make when you go grocery shopping, and one of them is deciding which shopping bag is better: reusable, paper or plastic shopping bags? As we all know, plastic bags are significant contributors to the garbage problem that we are facing now. 

According to the United States Environmental Protection Agency, people go through thousands of plastic bags every week, that's billions each year. This is the reason why we often see stray plastic bags in the streets, landfills, and the ocean. Plastic bags endanger marine life, wildlife, and they are not biodegradable. Although plastic bags can be recycled, they usually aren't. 

Paper bags, however, are biodegradable, and they are easy to compost or recycle. But making them in high volumes mean that a lot of water, fuel, and cut-down trees needs to be used. Paper bags are not made from recycled materials because most of them have stronger and longer fibers. 

Reusable bags are made from cotton, which is a pesticide-intensive and water-guzzling crop. These bags are usually made from nonwoven polypropylene plastic, and they can be bought anywhere. Reusable bags are better to produce because they are not as carbon-intensive as plastic bags. 

The best advantage of using a reusable bag is that you do not need a new one every time you use it. It can be used for a long as it can fulfill its purpose. You can wash it, dry it, and use it again in your next grocery shopping. 

The ones with the smallest carbon footprint are the single-use plastic bags, but what matters more is how we use the bag and how we dispose of them. The most important thing for eco-footprint is whether we reuse the bag or not, and if we do, we need to know how many times we use it before we throw it away. 

In 2011, an environment agency from the United Kingdom reported that paper bags must be reused at least two to three times in order to negate their climate-warming potential, compared to plastic bags. 

A reusable bag needs to be reused for at least 130 times so it can break even with a plastic bag, in terms of production and climate impact. Plastic bags can be reused too, but they do not look as presentable as reusable or paper bags. 

So which of these bags are sustainable? It depends on how many times you are going to use them and how you dispose of them afterward, especially for plastic bags. It is best if you use the bags that you know, you will reuse the most. 

No matter what kind of bag you use, in the end, it is the way that you use it that makes the difference. Think of which bag is more important to you.