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.