Natural? Artificial? It's all just atoms and the distinction is only in our minds. Discarded snail shells are also pollution. You may say that they break down a

Natural? Artificial? It's all just atoms and the distinction is only in our minds. Discarded snail shells are also pollution. You may say that they break down and plastic doesn't but bacteria are evolving that eat plastic. Coal only exists because when trees first evolved there was initially no life that could break down dead wood.