The combustion of oil makes up about 36% of the total anthropogenic carbon dioxide emissions. Coal (40%), natural gas (20%) and other sources (4%) account for the rest of human carbon dioxide emissions. What kind of anthropogenic carbon dioxide sources would fall under the category of "other"?

Question: What is the increase in atmospheric carbon dioxide concentration as a result of human activity over a one year period? Express the answer in ppm CO2.

We know that the mass of carbon released from the combustion of oil is approximately 3.40 Gt C/year (calculated in the "Your Turn" on the previous page). In moles this is:

The atmosphere contains about 1.8 x 1020 moles of gases. We can now calculate the fraction of CO2 relative to the entire atmosphere:

To express this ratio of CO2 to the whole atmosphere in ppm, the ratio must be multiplied by 1 million. We find that the concentration of CO2 released into the atmosphere from the combustion of oil is 1.6 ppm/year.

However, we need to take into consideration the other sources of anthropogenic CO2 in order to calculate humanity's total yearly carbon footprint. We know that the 1.6 ppm of CO2 released from combustion of oil makes up around 36% of total yearly CO2 emissions. This can be used to calculate the total yearly anthropogenic CO2 emissions: