Plastic bags sit in landfills, not moving, not biodegrading.  But that’s not actually a bad thing.  True, oil can’t be renewed.  But the plastic bags themselves can be efficiently burned as a fuel source.  Most incinerators used currently aren’t designed for this, but it can be (and on a small scale IS) done.
Paper bags kill trees, plastic ones don’t.  And paper bags weight more than 10 times as much, meaning the fossil fuel costs to ship them is exorbitantly higher.  My Plastics and Materials professor argues that plastic bags are, in the long term, possibly BETTER for the environment.

The big problem is oil… and embodied energy.  Burning plastic instead of recycling it is a terrible waste and very polluting.  Tom

I like to take my plastic bags and scoop up as many fish as possible, then tie it up and drop it back in the water.

A ban on plastic bags isn’t a ban on plastic. Plastic is incredible useful, particularly in medical fields, however it’s nothing but irresponsible to surround ourselves with it. Think of it this way: litter wouldn’t be a problem (as in contributing to our continent of plastic soup building in the pacific and making our communities appear neglected) if it was biodegradable. There really isn’t any decent excuse for it (it takes a helluva lot more processing to make a plastic bag than it does to make a bag out of paper, hemp, tweed, or another plant fiber that hasn’t been rotting under the earth for millions of years). Laziness isn’t going to get the human species anything but dead in half a dozen generations–it’s time to step up and concentrate on things that actually need done, for the betterment of all.

This is why problems don’t get solved.

Legalize marijuana! (sarcastic but probably true!)

Well what will I use for my garbage bags?  Those need to be disposable. 

Here in our country, stores are already converting to paper bags.

@Alba, no plastic is not more eco-friendly than paper or cloth due to the process by which it is made. The chemical waste of the processing process alone is an environmental travesty, to say nothing of the fact that most people do NOT recycle their plastic bags/bottles. Stop stating opinions as if they are facts and do your scientific research before you speak. 

Or you could revert to the 50′s and store everything is old paper grocery bags, or simply put everything in the trashcan outside without the bag. The concept of a trashcan in the kitchen is simply convenience. The gross organic stuff can be composted (including coffee grinds) and the metal and plastics can be washed and recycled. People have been disposing of their trash for millions of years just fine without their plastic bags. 

My brother in law in Germany has a company that makes a biodegradable additive that goes into the bags described in this article. After 90 days, the plastic bags are 90% biodegraded. If you are interested in finding out more on this topic, the name of the company is BIOP Biopolymer Technologies AGNot surprisingly, when he was trying to find investors for developing this technology, the only parties willing to help finance construction of facilities were those located in the Middle East and Asia. 

Plastic it’s good, people just don’t know how to use it…

And then I will have to buy garbage bags to dispose of my household waste.  This needs some thought.

If you do that in my area, they will not remove your trash (even though I pay over £25 per month in tax for them to do so).

All trash in my area and across nearly all of the UK, as well as many other developed countries Ive stayed in, requires trash to be self contained in individual trash bags when placed in a trash can.

Actually, alba is correct and you are wrong.  You should do some research before you post.

In my post above, I gave a link to detailed information, but surprisingly, paper bags, in the manufacture stage as well as the degrading and recycling stage, consumes more energy.

This is because, the paper needs to be treated to be resistant to tears, safe to hold enough weight, repel water and branded to be sold to naive fools like you.

The world already has it, as I mentioned above.  90 days is indeed impressive for 90% degradation, but bags in supermarkets for the past five years have been shown to degrade by over 95% after 180 days.

Plastic cleaned up it’s image a long time ago, unlike your ignorance.

No it won’t.  All it does is tax environmentally concious people (those that do use plastic).

People who “forget”, are the kind of people who may “forget” many things, hence being acclimatised to paying for convenience.

Buy a cloth bag a shut up.

Then what are those things flapping from the tree limbs?

I fail to see your point?

People litter all the time.  Instead of banning all packaging, so nothing can be sold in shops, just on the fear of someone littering or banning pets because people foul, we should instead educate society on general respect and correct disposal of items.

Banning plastic does not stop litter.  Slapping litter louts is a better route to follow.

After you.

You are partially correct, and your professor is correct.

This is a bit necrotic, but it needs rebutted, even if two months later:

Plastic BAGS are also a PART of modern medicine, and that’s WHY they are decidedly useful and inexpensive in general use in our societies.

If the government banned plastic bags or required merchants to charge obscene amounts for them, the problems you just described would be exactly the same, only, the costs of ordinary goods and services would be much higher; either (1) out of reach of ordinary wage earners, or (2) made worse by unjust fines or criminalizing this use after the fact (and that would include re-use), and that too, you will note, includes Health care use.

Liberalism kills. Obama’s expanded Bush-Doctrine is proof, militarily, and then there are the people who want us all to be “equal”… equally impoverished, equally powerless, and equally hopeless, socially.

No, thank you.

Kindly re-read “Animal Farm” by ‘George Orwell’… also, your factual errors and misgivings about plastics and petroleum and biodegradability are easily found at a site like wikipedia.