Op-Ed from 2011: In defense of plastic bags

Posted this because it brought up an interesting math question. It alleges "To ensure that they have lower global warming potential than conventional HDPE plastic bags" the following re-usable bags need to be reused x number of times:

-Paper bags: 3 times -LDPE (low density poly ethelyene) bags: 4 times -Non-woven PP (poly proplyene) bags: 11 times -Cotton bags: 131 times

The op-ed says that number has to be multiplied for every time a plastic bag is re-used for say, picking up dog crap, or as a bathroom trash bag.

Thoughts?