According to wikipedia (CO2):
As of January 2007, the earth’s atmospheric CO2 concentration is about 0.0383% by volume (383 ppmv) or 0.0582% by weight. This represents about 2.996×1012 tonnes, and is estimated to be 105 ppm (37.77%) above the pre-industrial average.
CO2 concentration by weight is obtained by the formula below:
0.0383 V% x [44.0095/28.97] = 0.0582 m% CO2
whereby molar mass=44.0095 g/mole
and mean molar mass of air=28.97 g/mole
Then, to obtain the total mass of CO2, via wikipedia: according to the National Center for Atmospheric Research, “The total mean mass of the atmosphere is 5.1480×1018 kg.
Thus, the total weight of CO2 = 0.0582% x 5.1480 x 1015 tonnes
= 2.996×1012 tonnes.
By applying the same formula, 4 other different values of CO2 concentration at different timeline as listed in the table below. Year 1750 is used for pre-industrial era (Industrial Revolution), 310 ppmv is obtained via the graph in 1960, and 2 predictions for year 2100 done by IPCC. The corresponding CO2 by total weight is calculated.
From year 1750 to 1960, additional 250 000 million tonnes CO2, or at the rate of 1190.48 million tonnes per year are added into atmosphere.
From year 1960 to 2007, another 570 000 million tonnes of CO2 are dumped into atmosphere, at much higher rate: 12127.7 million tonnes per year, which is about 10 times faster than the previous 2 centuries!
As of year 2002, human activities, especially fuel burning released 24,126.1 million tonnes of CO2 per year. This number is twice (2x) higher the rate calculated above. Could it mean that half of the CO2 released by human activity is managed to absorbed by carbon sink agents and thus not accounted into the CO2 concentration reading?
Let’s look at the future. IPCC gave 2 scenarios of the CO2 concentration (ppmv) by the year of 2100, 93 years away.
- To achieve 571 ppmv, the additional CO2 needed to add into atmosphere is 1.235 ×1012 tonnes, or 13 279.6 million tonnes per year. This is half of the rate of CO2 we are releasing today.
- To achieve 970 ppmv CO2 concentration, 4.558 x 1012 tonnes CO2, or 49 333.3 million tonnes per year is released. This is twice (2x) the number on CO2 emission rate what we are doing today!
Another perspective of looking at these numbers. At 2002, human activity released 24 216.1 million tonnes of CO2. Compared to the total CO2 mass in year 1750 (assuming it is in the state of equilibrium by then), that is accounted only 1.11%. What could this number mean?