Sometimes progress is ill-advised. We used to carry stuff in all sorts of containers. Then in 1965 a Swedish engineer invented the plastic shopping bag. It came to the US in 1979 and hit the big time thanks to Safeway and Kroger.
Part of the problem with single-use plastic bags is that they often escape the waste stream. HDPE or high-density polyethylene (plastic #2) bags litter roadsides, cling to trees and bushes, clog countless mechanical orifices, block storm drains, and spread their environmental havoc over centuries. To make more we keep pumping fossil fuel from the ground.
Meanwhile its alternative, the cotton bag, imposes its own environmental costs. It must be used two or three times a week for a year before it is less onerous to the climate than a plastic bag, primarily from need for chemical fertilizer for the cotton and the energy consumed by the fabric machinery.
The afterlife of an organic cotton bag entails decomposing back to the plant material from whence it came. A plastic bag does not decompose and will last in the environment for 500 years, physically degrading and becoming microplastics that absorb toxins and extend their reign of pollution. However, HDPE bags are recyclable into lower-order objects such as conduit and plumbing, if they are plucked from the waste stream.
Now that a plastic shopping bag ban is in place In New York State, the question is, “what substitution is best?” Craftspeople are weaving bags, totes, and other products from ribbons of clean plastic bags. Scaled up, this would make a dent and the result is surprisingly beautiful. Paper carries quite a footprint but is entirely compostable or recyclable. For everyone else, the solution is less complicated than it seems. The best bag, it turns out, is the one you already have. You simply need to remember to carry and use it.