Because reusable bags are bigger and more robust than plastic supermarket bags, they are more energy intensive to produce and transport. Of course, the waste they reduce through repeated use more than compensates for their initial energy investment. Over one year, replacing single-use plastic bags with woven HDPE (high density polyethylene) reusable bags is estimated to result in a 90% saving in energy use and greenhouse gas emissions.
The trouble is, I’ve managed to accumulate way more of these reusable bags than I can ever conceivably use — and I’m sure I’m not the only one who has! Most of my excess bags were donated by well-meaning family and friends. I only need a few bags for my weekly grocery shop, so the rest just languish at the bottom of a drawer until the next time I move house. It frustrates me that all the energy and materials used to create these spare bags is wasted.
The moral of the story? Consider clearing out that bag drawer and donating any excess bags to others who may need them. And if you have all the reusable bags you need, but you occasionally forget to bring them shopping, remember that accepting single-use plastic or paper bags (and disposing of them correctly) will likely have a lower environmental impact than buying yet another reusable bag.
P.S. On a related note, I saw this kick-ass canvas bag on the bus today: