Why does it take so long for trash to decompose in a land fill?

Answer 1

You'd think because our trash isn't a complex living organism it would decompose faster than a human might. Because much of our waste is man-made and not naturally created (along with the fact that we don't just bury it in the ground) plastic and aluminum take a much longer time to break down.

Another factor is that organisms leach, losing soluble carbon compounds by losing water. Trash doesn't retain water the way a plant does, so it doesn't go through this process.

Animals break down through autolysis, where the body's own chemicals and enzymes and bacteria breaks down the tissue. Again, trash doesn't naturally contain anything acidic enough on its own to break itself down, which is why it sits there.