Paper or plastic?

So you think the reason not to use plastic bags is global warming? Not really.

While fossil fuels are used to manufacture the bags, the key reason behind the push to phase them out is old-fashioned pollution: They litter the landscape and can hang around for hundreds of years.

The grocery chain Whole Foods is phasing out plastic bags - most local stores stopped giving them out as of last week.

But before you ask for paper instead, consider both types of bags' true environmental impact.

It may make you reach for a canvas sack - if you don't have one, conservationists suggest picking the bag you are most likely to reuse.

BETH DALEY