How quickly are we changing our ways?

While gardening this morning, I dug up an old plastic supermarket bag. How do I know it's old? Certainly not by the condition of the plastic. A wipe with a damp cloth and it was as good as the day it was carried from the checkout to the car. I know it's considerably more than ten years old because it was buried in an area of my property that hasn't been disturbed in the ten years since I acquired it. In fact, when I moved to this place, it was apparent from the overgrowth that the area hadn't been disturbed for many a year before that.

Now, gardening always sets me to thinking. That's part of why I find it therapeutic. But this subterranean find gave me something to think about. Have a look at the proud claim made by the chest-beating grocery chain of the day:

On the positive side, some (former?) perpetrators of eco-vandalism have progressed from a world where credit could be claimed for saving resources and providing a use for previously used materials, to a world where some of them provide disincentives to the use of environmentally harmful materials - e.g. charging for plastic bags. But on the negative side, it's slow progress indeed. The other point worth considering is the seemingly indestructible nature of the material. If it's still in perfect condition after 10-20 years in the soil, how many generations is it going to be before it disappears - if ever?