When the plastics reach the apex of second half-life they will lose all mass and become weightless misshapen orbs of light, floating up out of the depths of the oceans to disperse and litter the skies, eventually forming a vast blanket around the planet and reflecting the sun’s energy back into space. By this time humans will have devolved into tadpoles incapable of abstraction and the petrochemical winter will blot out most of the higher life forms.
Somewhere, in a self-sustaining cryogenic chamber, one man will survive to fight back against the coming end of civilization. That man will be played by Vin Diesel. No, no. Nicolas Cage.