On greenhouse gas emissions alone, reusable plastic bags need to be used about ten times to be as good as single-use plastic, and cotton bags over 100 times. Paper bags are no better than single-use plastic.
On total environmental impact, single-use plastic pulls further ahead: paper bags are much worse, reusable plastic bags need to be used 50 times to match single-use plastic (achievable with focus and effort), and cotton bags take thousands of uses to equal single-use plastic.
And if you reuse single-use plastic bags for trash bags, they are far superior to all alternatives.
Does this account for the fact that reusable bags are larger capacity and stronger than single use bags (don't need doubling).
Also, single use bags , as the name suggests, are used in far far higher quantities than trash bags. A week means 1 trash bag but a dozen grocery bags.
Anyway, regardless of that your shopping bag is, most of the plastit is inside it, wrapping your individual items...
On greenhouse gas emissions alone, reusable plastic bags need to be used about ten times to be as good as single-use plastic, and cotton bags over 100 times. Paper bags are no better than single-use plastic.
On total environmental impact, single-use plastic pulls further ahead: paper bags are much worse, reusable plastic bags need to be used 50 times to match single-use plastic (achievable with focus and effort), and cotton bags take thousands of uses to equal single-use plastic.
And if you reuse single-use plastic bags for trash bags, they are far superior to all alternatives.