I remember reading that most of the fossil fuels on earth were deposited before mushrooms and other fungi evolved which break down organic matter. Before they e

I remember reading that most of the fossil fuels on earth were deposited before mushrooms and other fungi evolved which break down organic matter. Before they existed, organic material did not decay nearly as fast as it does now, so it would just pile up. That's why there is so much fossil fuel around, but it probably wont ever be replenished to the same levels. I forget where I read this, so I could be misremembering. In any case, there's no guarantee that fossil fuels will exist.