Atmospheric O2 Depletion

Since we are still burning carbon based fuels for energy and the amount of CO2 produced is changing the oceans acidic levels, I was wondering if we are slowly depleting our air of oxygen. In cars 1 pound of fuel requires 14 pound of oxygen and considering all other fossil fuel usage we are bonding an enormous amount of oxygen into carbon dioxide. Considering the increased use of fossil fuels by China and other developing countries what are your thoughts on this issue? Ed