Primordial soup was when the earths early atmosphere contained small amounts of ammonia and nitrogen and stuff. Lightening struck this, and formed simple amino acids, which eventually evolved into microorganisms and the such.
The earth used to have mainly volcanoes and a carbon rich atmosphere. The earth cooled down, and oceans were formed and plants evolved, which did photosynthesis and stuff
Then yea. Not much carbon anymore bc plants and limestone and stuff
Remember this buddy ;^)