Puzzled by the lack of information flowing from Toronto City Hall about the ban on shopping bags, I wanted to get to the bottom line on how I will be lining my garbage and composting containers in the future. And there's that little matter of carrying my food and booze home...

I know, I know. Bring a reusable shopping bag with me. Sure, fine. But sometimes I impulse shop. I will be out for a walk and decide I want a to make something and I need groceries or a billboard will catch my eye and I will run right in and buy some booze (Yeah, right.)

Grocery stores are charging a nickel for the killer bags and the LCBO is handing out paper bags instead of plastic bags. Really bad idea. (But I will get to that later.) Canadians go through tens, possibly hundreds, of millions of plastic shopping bags every year. Only a small percentage of plastic packaging is recycled; the rest ends up in landfills or as litter.

Vast quantities of plastic bags are blown away from landfills before they can be buried. Aside from being unsightly, this litter is lethal. Many birds and marine animals die every year from ingesting plastic bags. Even after the animal has decomposed, the bag remains intact.

Paper Bags Are Not the Answer

At first glance, paper bags seem to be the solution: they're made from a renewable resource, and they're biodegradable and recyclable. But in many ways, paper bags are even worse than plastic bags. Paper bags consume many times more energy to create and transport than plastic bags. Manufacturing paper bags also puts out a considerable amount of air pollution and consumes a lot of water, producing 50 times more water pollutants and generating much more CO2 than plastic bags in their production. It takes 91 percent less energy to recycle a pound of plastic than it takes to recycle a pound of paper. And paper bags can't even be used in composting programs. And come on, they're useless in wet weather!

Early Attempts at Biodegradable Bags

The clear solution is a bag that combines the ruggedness and low bulk of plastic with the biodegradability of organic materials. The first attempts at such a bag were made a couple of decades ago. But these early "eco" bags often didn't disintegrate completely, and left behind large plastic flakes, pellets, or resins. Some of those bags are still sold today, though they don't measure up to modern industry norms for biodegradability or compostability.

The Solution

Plastics based on renewable feedstocks from companies like Metabolix and Novamont show tremendous potential and promise to alleviate many municipal solid waste concerns. Metabolix is based in Cambridge, MA, and signed a joint venture with agribusiness giant Archer Daniels Midland (ADM) to develop its corn sugar-based biodegradable polymer, while Novamont is already a supplier to Bio-Bag® producer Bio-Bag USA.

But until recently, biodegradable plastic bags have cost at least three times more and fallen short on performance, but the picture is changing. Currently, most biodegradable plastic bags are produced by blending plant starch with petroleum-based polyesters, which improves the bag's strength and processibility but continues our dependance on foreign oil and leaves those pellets or resin behind. And, these so-called bio bags cost three to four cents more than the one-to-two-cents-per-bag cost of polyethylene.

But a true corn sugar-based biodegradable bag, (And just so we're clear here, the process is basically taking a cob of corn apart by breaking it down to corn starch and corn sugar, then reanimating it in the shape of a shopping bag) has the potential to cost less, reduce our oil dependance, use less energy, produce two-thirds less greenhouse gasses than the manufacture of plastic bags and leave no trace once degraded in 12 to 24 months.

Surely these corn-bags will become the sweetheart of curbside organic-waste recycling programs across North America.

Or Will They?

Corn-Bags, as I like to call them to avoid confusion, seem like a good idea, but they have their detractors who believe significant downsides exist. Some of their information may not apply to Corn-bags specifically, but their concerns are:

• Corn-Bags do nothing to address the consumption part of this problem which lies at the heart of this issue. We're still burning energy and natural resources to produce them.
  
  
• Grocery chains would love to save several pennies per shopper by not having to hand out bags of any kind. Thinking that a Corn-Bag is harmless may result in increased instances of littering.
  
  
• When used Bio and Corn-bags become litter and blow into streams, rivers, lakes and oceans, the breakdown of the starch-based films in the water consumes oxygen, resulting in oxygen depletion that contributes to algae blooms and the death of marine life. Birds and animals will still become entangled in the discarded bags and if ingested, they would suffocate before the bags have time to decompose.
  
  
• Currently, mixing biodegradable bags in with conventional plastic bags in recycling systems designed for conventional plastic bags only creates a sorting nightmare and can render entire batches of recyclable plastic useless.
  
  
• While water, soil, and crop contamination could result from the use of compost with chemical residues from petroleum based biodegraded bags, it is as yet unknown what high levels of corn starch and modified corn sugars will do to things like the pH balance of soil or what the biodegrading process will result in long term with respect to soil, water and air quality.

Hopefully municipalities like Toronto will get it right someday. You know, the day they ban all plastic and petroleum based bags, INCLUDING those rolls of bags you see in the grocery store vegetable isle, and retrain citizens to bring their own reusable bags. Then, they can allow retailers to provide people who forget or impulse shop to use FREELY PROVIDED Corn-Bags.

Until then, do the right thing and BYOB - bring your own bag!

This Just In!!!

Are plastic bags actually greener than paper?

I find certainty a little dubious.

Somehow, nothing has ever seemed that certain on this earth, so when people--especially scientists or green activists--claim they know everything, my skeptical muscle goes all Cirque du Soleil.

So please raise an eyebrow with me to a stimulating article in the Independent newspaper. It reveals the existence of a report, commissioned by the U.K. government, that concludes that plastic bags are actually less harmful to the environment than either paper or cotton versions.

I know that doesn't sound right, does it? I live the merest gust of wind away from San Francisco, where plastic bags are banned. I have always been told that paper is green, recyclable, and the finest way we can make use of the Amazon forest.

So how could it be that high-density polythene is actually greener?

Might they be greener after all?

Well, this report, created by Chris Edwards and Jonna Meyhoff Fry at the behest of the U.K. Environment Agency, reportedly says that ordinary plastic bags are 200 times more climate-friendly than those cotton carriers favored by so many environmentalist preachers.

If that isn't exciting enough for you to question your precepts and sanity, the report also reportedly claims that these put-upon, downtrodden plastic carriers emit one-third of the carbon dioxide of paper bags.

The researchers made a very simple conclusion--that plastic bags are greener because they're far lighter.

Here's what I find slightly curious about this study: it hasn't been published yet. Even though it was reportedly presented a year ago. It is still being reviewed by peers, although the U.K. Environment Agency promises it will see encounter the public eye soon.

The agency also created a frisson of excitement when it told the Independent that the reviewers "questioned some aspects of the original draft, although much was about emphasis and balance."

I am sure there will be many emphatic, balanced, and sober scientists all over the world who will await this report with some glee.

The plastic bag has been such a universally useful invention that it would be a shame to see it disappear. It can hold so much of your life in one eminently foldable item. It can even keep your possessions--especially when you've been kicked out of an apartment and are walking the streets in despair--mostly dry.

To merely imagine that it might be greener than all the items barkingly suggested by the Green Police might give some curious hope for the future. I know there are many who crave the days when, after being asked "paper or plastic?" they were proud to say the latter.