(Credit: CC0 Public Domain)
To understand the full spectrum of impacts and benefits of a particular bag, we need to analyze its life cycle, states an article on Phys.org. A life cycle analysis (LCA) looks at how much energy is used and how many environmental impacts a product is responsible for at every stage of its life, from cradle to grave. This includes extracting the raw materials, refining them, manufacturing the product, packaging it for shipment, transporting and distributing it, its use and possible reuse, recycling and final disposal.
In any LCA, the total environmental impact also depends on how efficient each process is, and how many protective environmental measures are implemented at every stage. Energy use is also subject to variables such as the source of raw materials, the location of manufacturing and processing, how long a product is used and the final disposal method.
Life cycle studies done in Europe and North America have determined that, overall, plastic bags are better for the environment than paper or reusable bags unless the latter are used many times. Most, however, did not consider the problem of litter, which we know is a major drawback of plastic bags.
