I wonder if the plastic we deposit into the environment will form oil/coal deposit layers in a few million years? Or will microbes develop means to digest all those energy rich hydrogen carbon bonds those polymers are composed of. Much like our coal/oil deposits date back to before evolution a means to metabolize cellulose.
>To form coal you need two basic conditions: wet tropics and a hole to bury organic matter in for a long period of time,” Boyce says. During the formation of Pangea, collisions between continents raised mountain ranges while downwarping adjacent crust, which created massive basins. These basins became ideal depositories for wet organic plant matter, which was buried, compressed and cooked over geologic time to form coal. Similar conditions likely also produced coal deposits during the Mesozoic Era, and the Paleocene and Eocene epochs, often in conjunction with mountain-building episodes such as the formation of the Rocky Mountains.
Everything is a compromise: making pants slightly stretchy makes them fit better, but like everything, there's a downside, being reduced lifetime in this case.