Currently oxygen is about 20% of the atmosphere. In the Carboniferous period, 60 million years ago, it’s thought to have gotten as high as 30%.
Oxygen is highly reactive, and the O2 configuration is not particularly stable, so over time it gets locked up in other molecules, which are then burred or deposited at the bottom of bodies of water.
Oxygen has always been plentiful on earth, but for most of geologic history it was bound up in solid molecules in the crust. Nearly 2.5 billion years ago, bacteria began “unlocking” gaseous O2 as a byproduct of the nitrogen based chemical reaction they lived on.
How much was the oxygen and where has it gone since then?
Currently oxygen is about 20% of the atmosphere. In the Carboniferous period, 60 million years ago, it’s thought to have gotten as high as 30%.
Oxygen is highly reactive, and the O2 configuration is not particularly stable, so over time it gets locked up in other molecules, which are then burred or deposited at the bottom of bodies of water.
Oxygen has always been plentiful on earth, but for most of geologic history it was bound up in solid molecules in the crust. Nearly 2.5 billion years ago, bacteria began “unlocking” gaseous O2 as a byproduct of the nitrogen based chemical reaction they lived on.