## Consequence for Percentage of Oxygen in Atmosphere of Burning all Biomass and Fossil Fuels

Suppose all the carbon is burnt via the equation:

\[C_2 H_4 +3O_2 \rightarrow 2CO_2 +2H_2O\]

Three times as many oxygen atoms are consumed in this equations as oxygen atoms.

There are a total of 5610 GT of carbon available to be burnt. This is

\[\frac{5610 \times 10^9 \times 10^3}{0.012} = 4.675 \times 10^{17} \: mol\]

We will require three times as many oxygen atoms as carbon atoms. Since oxygen molecules occur as

\[O_2\]

, this means 1.5 times as many moles of oxygen, so we require \[1.5 \times 4.675 \times 10^{17} = 7.01 \times 10^{17} \: mol\]

of oxygen.The mass of 1 mol of oxygen is 32 g, so we need

\[7.01 \times 10^{17} \times 0.032 = 2.243 \times 10^{16} \: kg\]

.The mass of oxygen in the atmosphere is about

\[1.176 \times 10^{18} \: kg\]

This is the total mass of oxygen burn up by burning all the carbon in the biosphere and fossil fuels. It is a fraction

\[\frac{2.243 \times 10^{16}}{1.176 \times 10^{18}}= 0.019\]

of the oxygen in the atmosphere.There are substantial masses of carbon in the soil and oceans (1600 GT and 40,000 GT) respectively. If this is released into the atmosphere as a result of global warming, the calculations above could be substantially different.