It's erroneous to apply 20th century logic to the ancient world when the environment was so drastically different then that it's impossible to compare the 2. There was little if any polution, wood was a lot newer because trees were newer and there were many more different tree genera than there are now!
Man still cannot explain how the first cells, molecules, atoms, etc. got here but they nevertheless exist. So just because man cannot understand the ancient world doesn't at all mean it didn't exist!