Polymers, such as plastic shopping bags and plastic water bottles, are probably among the most numerous products in landfills.  In addition to filling garbage dumps, these products wind up on the sides of roads and in oceans, where they will dwell for most of eternity.  The problem with polymers is that they don't decay over time.  A wooden table will eventually degrade and rot given enough time.  Banana peels and apple cores will break down, leaving nothing.  Cardboard boxes, newspapers, magazines, and cigarette butts will likely break down into smaller and smaller components until there's next to nothing left.  But plastics stick around forever.  No amount of time, water, wear, or natural heat will cause a plastic to cease to exist. 

The Great Pacific Garbage Patch is an area in the Pacific Ocean, twice the size of Texas, absolutely full of floating plastic garbage.  It's located in an area where different ocean currents and pressure systems cause the water to basically form a giant swirling vortex.  A witness describes it:  "It began with a line of plastic bags ghosting the surface, followed by an ugly tangle of junk: nets and ropes and bottles, motor-oil jugs and cracked bath toys, a mangled tarp. Tires. A traffic cone."  He goes on to say, "Except for the small amount that's been incinerated--and it's a very small amount--every bit of plastic ever made still exists." 

Update:  There's one in the Atlantic Ocean too.

I have a prediction:  In the somewhat near future, the highest-paid job, the most sought-after applicant, and the Nobel prize winner will have something in common:  They'll invent a method of polymer destruction.  It would be even better if the inventor came up with a way to use the destroyed polymer for some sort of good, like energy generation or something like it.  I have two suggestions for the would-be inventor: 
  1. Perhaps try the sun.  That giant ball of fire in the sky puts out quite a bit of heat.  Maybe we can load up a giant missile with tons and tons of plastic garbage and shoot it into the sun, where it'll spontaneously vaporize and probably cause no harm to humans.  That might be a bit expensive though.
  2. Perhaps try a volcano.  Volcanoes pump out tons of heat, and their liquid magma will probably melt anything you put in it.  I can't verify the toxicity of the resulting smoke and soot, but chances are it would be bad.
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