Re: VRD - Atmospheric Oxygen decrease

I am taking a meteorology course from a professor at South Dakota School of 
Mines and Technology. He discussed this topic about 3 weeks ago. His 
statement was that the amount of O2 in the atmosphere fluctuates by small 
amounts, but has been relatively stable  since our planet first developed 
an atmosphere. I was surprised at this, since I thought one of the reasons 
to quit burning rain forests was to keep plants to produce ozone, but I was 
wrong. When plants die, they decay, and that consumes O2, just as burning 
does. Plants also use O2 in their metabolism, although they produce more O2 
than they burn. So , no, the amount of O2 in the atmosphere is not 
radically decreasing.