Save the trees! Use plastic instead of paper!

Oops, sorry, wrong decade. Hard to believe that was once the cry of environmentalists, isn't it? But the road to hell is paved with good intentions, and we soon discovered plastic bags have their own environmental baggage.

New York City now goes through more than 5 billion plastic bags each year, which pollute the seas and highways, and endanger fish and wildlife. Usually crammed into landfills at a cost of millions yearly, the plastic bags are virtually indestructible. Now, the City Council is considering a 10-cent-per-bag charge at supermarkets and other grocers to limit the use of plastic and protect the environment.

Who could possibly quibble with that? Funny you should ask.

Let's start with the law of unintended consequences. For example, we can agree that alcohol abuse leads to accidents, health problems, broken homes and other mayhem. To counter this, the U.S. government decided to enact Prohibition in the 1920s. Did people stop drinking? Ha! This misguided effort strengthened organized crime, which took over the then-illegal trade.

Will the proposed law have similar consequences? Perhaps. Some key questions must be answered. Such as, how will you lug your groceries home? In canvas bags, which most grocery outlets would sell. When you buy chicken, for instance, most stores put it in a separate plastic bag to prevent contamination of other food. But forget to wash your canvas bag, and you'll be "going green," all right.

One of two things will happen: People won't wash the canvas bags regularly, which will make them bacteria traps, or they will, which will increase the use of water, detergent and electricity. Not exactly great for the environment.

Meanwhile, how will you throw out your garbage? Pick up your dog poop? People already reuse their plastic bags for these purposes. If the law passes, New Yorkers will still be buying more plastic garbage bags -- from the same supermarkets that will be charging them for using plastic bags.

Something must be done about the proliferation of plastic bags, and the proposal aims to do that. But let's also keep in mind the law of unintended consequences.