oxygen is created by photosynthesis and net emission
due to burial of atmospheric carbon (CO2)
oxygen is consumed by both living beings and the
net uptake of oxygen due to weathering of fossilized carbon
...... where does most of the oxygen in the Earth
system reside?
most of the Earth's oxygen resides
in mineral oxides of the crust
a small fraction resides in the atmosphere
and an even smaller fraction resides in the biosphere
still the biosphere is crucial to understanding
the atmospheric oxygen budget as it controls short term exchanges between
sediments and the atmosphere