Arguments have long raged over which type of bag is worse for the environment: paper requires more energy to produce and ship, but can be generated from renewable paper stock, and is more often recycled. Plastic is cheaper and requires less energy and water to produce and transport, but is not a renewable resource. And, city officials argue, too many plastic bags end up as litter on city streets, clogging storm drains, and harming wildlife. Many eventually join the giant island of plastic trash floating in the Pacific Ocean as well.

The city will start enforcing the law in December, with fines starting at $100 and going up to $500. The law is a first in the US, with Oakland following suit in a few months, and London and Paris considering the measure as well. But while cities can mandate away the choice between paper and plastic, it will be up to consumers to make the real environmental choice – using backpacks, baskets or the increasingly popular canvas bags now being sold in stores everywhere.

And now that San Francisco has taken on grocery bags, one wonders how long will large retail stores still be allowed to hand out their giant plastic bags? Something to think about during the holiday shopping season which officially begins right after that Turkey dinner on Thursday.