Wal-Mart now has reusable shopping bags for sale, which would reduce the number of plastic bags used. To understand the disadvantage of plastic bags, try this: next time you drive your car from work to home, count how many plastic bags you see along the way.
Here is the fact. A reusable bag must be used 9-13 times before the environmental damage from reusable bags is less than the damage from plastic bags.
Carl Bialik. The Wall Street Journal. September 24-25, 2011. A2.