Here in the United States, we're still wrestling with the issue.
Some places have banned the bags. Some charge a fee. But if the shoppers at my local grocery are indicative, many people embrace the convenience and say the heck with the planet.
In this season of shopping and entertaining, the bags inevitably mount.
This must stop.
Practically, the issue is about resources. Valuable fossil fuels - natural gas, for the most part - go into the manufacture of plastic bags.
Litter is also an issue. A 2008 study of the Anacostia watershed outside Washington - before a fee was instituted - found that 50 percent of the trash in tributaries was plastic bags.
The bags are also symbolic - probably nothing typifies our disposable society as much as plastic bags.
The industry has squirmed every which way to fight bans and fees, which obviously would blunt the bottom line.
The industry fought vigorously when Philadelphia proposed a fee, which had been touted in the city's Greenworks sustainability plan. Mayor Nutter once chanted, "No more plastic bags!" But in 2009, the attempt failed; it has not been resurrected.
The industry's counteroffer is plastic-bag recycling. While many environmental groups aren't enthralled, the industry has found a strong ally: antilitter groups.
Plastic-bag recycling is now the major campaign of Keep Philadelphia Beautiful, which also receives some funding from the American Chemistry Council, parent of the plastic-bag industry group, Progressive Bag Affiliates.
KPB executive director Phoebe Coles explained that the group's focus was on behavior, not products. She said the same went for cigarette butts: They address the litter, not the smoking itself.
In 2009, KPB partnered with Temple University to collect enough bags to bury its iconic bell tower.
Last month, KPB joined a wider public education campaign, A Bag's Life, with a website (www.abagslife.com) and an app to help people find drop-off locations.
Many stores, from groceries to big-box businesses, now have collection bins - usually up front - for plastic bags.
And they're not so quick to hand out the bags anymore either. Wawa, for instance, is retraining its employees to ask customers with just one or two items if they need a plastic bag vs. automatically bagging all transactions.
Much of the material KPB and its numerous retail partners collect goes to Trex Co. Inc., which makes plastic lumber and decking from half bags and wraps, half scrap wood, said Dave Heglas, director of materials resources for Trex.
But look around. If you see a bin marked "Bag-2-Bag," that plastic is going to Hilex Poly L.L.C., which has a $13 million facility in Indiana that washes them, processes them into pellets, then turns them back into bags.
This can be endless, a Hilex spokeswoman said. The plastic eventually weakens, but pellets from stiffer wrapping (such as the stuff around paper towels) can be added for strength.
Still, the industry has a way to go. According to U.S. Environmental Protection Agency statistics, only 4.3 percent of HDPE bags - the typical grocery bag - were recycled in 2010.
The rest - about 660,000 tons worth - were tossed, albeit often after being reused for dog poop, kitty litter scoopings, and trash-can liners. The industry says 60 percent get a second use before being discarded.
Because of the blow-ability of lightweight grocery sacks, many antilitter folks urge people to recycle their grocery bags and buy heftier bags for trash. But this doesn't sit well with environmental groups worried about resources going to landfills.
"We simply have to stop the free distribution of bags" - all bags, said Allen Hershkowitz, a senior scientist with the Natural Resources Defense Council, a national nonprofit.
But he can't support a ban. "Millions of people every day use some disposable bag," he said. "We can't take that convenience away from people without expecting a huge backlash against environmental causes."
He wants to see fees. The money collected could fund education and, as in D.C., river cleanups.
If the experience of the Weavers Way Co-Op stores in Chestnut Hill and Mount Airy is any indication, people might accept it.
The co-op offers no plastic grocery bags. It charges for everything else - two cents for plastic produce bags, four cents for a small paper bag, and 15 cents for a large paper bag with handles.
"We don't get any flak about it," said general manager Glenn Bergman.
In my own house, we've had a race on for more than a year - trash vs. bags.
We're fairly vigilant about reusable bags, but if someone forgets, it's not a crisis.
We reuse the plastic bags we do get as trash bags. With recycling and composting, we don't need many of them anyway. And with less trash, they don't have to be very big - even a little grocery bag in the bin under the kitchen sink lasts for days.
I've been waiting to see if we'll ever have more trash than bags. I suppose this says a lot about the ubiquity of the bags: We've never run out.
GreenSpace: Plastic Bags and More . . .
Below is a list of materials besides plastic bags that can be recycled in special bins at some groceries, big box stores, and more.
Dry cleaner bags
Product wrap (from paper towels, toilet tissue, napkins, soda bottles)
NOTE: Plastic bags CANNOT be recycled curbside in this area. Putting other recyclables
in a plastic bag causes problems. Waste Management Inc. reports that at its new sorting facility in Northeast Philadelphia, the machinery has to be shut down for 30 minutes every four hours so workers can clear the plastic-bag clogs.
"GreenSpace" appears every other week, alternating with Art Carey's "Well Being" column. Contact staff writer Sandy Bauers at 215-854-5147, firstname.lastname@example.org,
or @sbauers on Twitter.
Visit her blog at www.philly.com/greenspace.