Quick! What's the housing of your computer screen made out of? What about the dash of your car?
If you struggled for a moment, I wouldn't be surprised. The first question is ripped directly from the pages of an interesting book I'm reading by Geoff Nunberg of NPR fame called, Going Nucular[sic]. I'm still at the beginning but it's proving very enlightening. Nunberg, a linguist who specializes (according to Wikipedia) in lexical semantics, writes about the various ways our word-choice has transformed over the years- shaped by our environment and culture. I bought his book on a lark, literally picking up the first paperback with an interesting title because I had to break a hundred.
At the very beginning, he hits upon something anyone with an interest in synthetics has considered, however obliquely. He talks about how the word "plastic" shifted from something that indicated status and modernity to a word that has fallen out of vogue, a word that indicates superficiality, the cheap, the disposable, and waste. However, chances are, most everything in your modern life has some quantity of plastic in it. Even something like a spiral bound notebook, a very basic invention, might have a thin layer of plastic on the cardbard cover. Pens, which used to merit the actual business of "pen repair" are now throwaway plastic tubes. Even in more expensive pens that use refill cartridges, those cartridges will have some quantity of plastic.
Of course, not all plastic is created equal. In the AMC hit show, Breaking Bad, where the main character is a chemist who is forced by his cancer and financial situation to make and sell crystal meth, this is illustrated when they want to dispose of a body by dissolving it in acid. This scene will be with me for the rest of my life simply because it was so satisfying for me to watch. He specifically requests his partner (a non-chemist) get a large plastic tub with a resin identification code that labeled it as LDPE. These are the little "recyclable" icons with a number inside that you see on plastic products.
Plastics are made up of long chains of molecules called polymers. This gives plastic its characteristic flexibility. In the case of LDPE, the plastic is fairly non-reactive with concentrated acids. (Though if you throw an organic solvent on it, it will practically "thaw" before your eyes). His partner, repulsed by the thought of having to cut the body up to fit into the two containers, decides to use the bathtub. The bathtub is made of conventional ceramic (basically clay that has taken on a structure similar to glass) and is attacked by the strong hydroflouric acid solution and we get a (literal) bloody mess when the partially decomposed body pours through the floor into the hallway below. Hydrofluoric acid, I might add, is extremely dangerous. Most simple, strong acids will merely burn you. HF is absorbed through the skin very easily and acts as a poison since the fluorine binds strongly to the calcium ions in the bloodstream. These ions are critical to the function of our nervous system and muscles. It's essentially a rudimentary neurotoxin (though some neuroscientists may prefer to use the term more restrictively).
It's the characteristic nonreactive nature of plastic that makes it so useful, and so harmful to the environment. While recent studies have shown that plastic can in the right conditions, degrade naturally, the vast majority of plastic waste will continue to pose an environmental hazard indefinitely. Plastic breaks down mechanically over time, mixing with soil and entering the food chain. This is how plastic got to be such a dirty word. Plastic was the material of the future for a while. Disney had an exhibition called "House of the Future" where the entire structure was made of plastic. Legend has it that the wrecking ball essentially bounced off of it when the time came to tear it down. With increasing environmental consciousness (and presumably, hippies) the plastic craze died down.
Despite the fact that plastic can be recycled (the resin codes I mentioned earlier were designed to facilitate recycling) it's an energy intensive process- one that inevitably leads to more emissions. This is why the mantra of the environmentally conscious is, "Reduce. Reuse. Period." Some attempts are being made at creating plastics that do chemically degrade. The only problem with this is that one of the things that makes plastic so useful is the fact that it doesn't break down easily over time. Still this may prove useful for such things as single-serving beverage bottles, disposable cups, straws, etc.
Alas, modern life is simply not possible without plastic. Remember the computer and your car's dash. Laptops are affordable and portable because they are made of plastic. They're also more resilient and tolerant of drops and shocks than they would be otherwise. Similarly, in an accident, if your airbags fail, you don't want to slam your face into a wood, steel, or aluminum surface. Also, imagine the money you save on gas driving a car not entirely made of metal and wood.
I'm not saying that it is entirely impossible or futile to eliminate synthetic plastics from our world, but it does no good to be in denial of the challenges that face scientifically-sound environmentalism. There needs to be acknowledgment on some level that plastic isn't going anywhere. We should be reducing and reusing as much as possible until a more permanent solution is found. A metal canister/cans for drinks, paper cups, and less packaging are all steps that can be taken to reduce the amount of plastic that ends up in the ecosystem. Energy-efficient systems and infrastructure for plastic recycling and disposal are going to have to be critical areas of development in the future.