Abstract:  Consideration is given to the theoretical matters 
or elements that may affect the percentage amount of 
atmospheric oxygen within the oxygen equilibrium status as 
it is affected by global warming.

Restated:  At what point are we going to unable to breath 
sufficient oxygen to maintain consciousness due to our 
stupidity?  

As you probably know by now, if you have spent hours 
underwater chasing schools of nine and one half feet long 
barracuda in the warm Indonesian waters, mammals require 
oxygen to breath to remain conscious.

When we are conscious we can act substantially rational, but 
when we are unconscious, we can hardly act at all, 
especially in the interest of advancing the suitableness of 
a nurturing mother earth that is appropriate for the 
sustaination of the future generations of our children

rephrased:  The dead got no gitgo.
                                                    
So:  What are the elements necessary in the oxygen 
equilibrium that are necessary to promote life?

Now keep in mind that for a joseph sixpack all these 
equilibrium 'vectors' are merely simple minded 'theoretical 
speculation' and that the real numbers are going to have to 
be worked out by professionals.

Let's start by measuring the volume of the air that contains 
a breathable supply of oxygen.  That would amount to a thin 
spherical of some dimension.  Let's see that would be:


Vmax = 4/3 pi R13 (where 
R1 is the effective net radius in some units of 
measurement of the earth at the top sustainable altitude of 
breathable oxygen plus an extra some undecided amount added 
to R1 to CYA on the ultra thin oxygen content at 
the remainder of the ultra high atmosphere.

Minus (then we subtract)

Vground = 4/3 pi (R23 which 
equals the actual radius of the earth in the same units of 
measurement.

So Vmax - Vground = a thin eggshell of 
atmospheric volume of atmosphere.  Or restated:  a somewhat 
thin volume of atmosphere that is oxygenated and involved in 
promoting life for oxygen breathing fauna.

Now the atmosphere is about 21% oxygen i read 
somewhere.  So we have to multiply the net volume of raw 
atmosphere by 21% (.21) to get the actual amount of 
oxygen involved.

Now the amount of oxygen in the atmosphere that can exist 
but still cannot support our life is an amount that is 
designated or called by climbers, 'the death zone' and that 
amount amounts to around fourteen (14) percent oxygen.  That 
is equivalent to the amount of oxygen that is found at an 
altitude of about 8,000 meters.  And that is the 14% 
amount, or when humans start 'blacking out'.

So if we separate the oxygen from the nitrogen we get about 
21% oxygen and the rest 79% remaining gases:  
nitrogen, CO2, and other gases.

Now looking down at the top of the earth we see or imagine a 
circle of 360°.  Now 21% of that circle contains 
the oxygen which is approximately equals 76 degrees and the 
other 284 degrees contains all the other gases

But if 14% of the atmosphere is oxygen then only 50.4° 
equals the amount of oxygen in the atmosphere.

It's easy to see that 21 - 14 equals 7 so we have to reduce 
the oxygen in the atmosphere by only a third of its 
currently existing volume and we have reached the effective 
'death zone' conditions for mankind and probably a sizable 
percentage of most other mammals as well.

Now the issue becomes:  What is going to reduce the oxygen 
in the atmosphere?

Well, for one, if the ambient temperature of the earth rises 
to the extent that it heats up the surface areas of the 
oceans that contain the items (fauna) that generate the 
oxygen to the extent that it becomes impossible for them to 
exist, then the equilibrium of the oxygen production and the 
oxygen destruction will be shifted downward or towards a 
lesser percent of atmospheric oxygen content.

With oxygen destruction items remaining the same, the oxygen 
percentages within the atmosphere will decline.  To what 
extent and duration of decline, we will have to leave to the 
scientists.  

But off the top of a Joseph_Sixpack's head, lightning caused 
forest fires would reduce the oxygen in the atmosphere.

Enormous amounts of evaporating undersea methane might on 
occasion form a combustible mixture that would further 
reduce the oxygen to CO2 and water.

The plants would love the CO2 and would pump out 
oxygen.  The whole thing is a nightmare of unmeasurable and 
indeterminate variables well beyond a joe.

The only thing to do is to periodically measure the 
percentage amount of oxygen in the atmosphere to see if it 
dropping in a critical fashion to offer some threat to 
mankind if the oceans cease to produce oxygen.

There may be some other issues involved as well if too high 
a percentage of oxygen in the atmosphere is produced 
combined with global warming.