About 70 \% of total global carbon is found in

The atmosphere is the source of carbon dioxide, which is utilized by plants in photosynthesis reduced to form carbon compounds. The total mass of carbon currently in the atmosphere is about $7 \times 10^{17} \mathrm{~g}$, ie, 700000 million tonnes. Oceans regulate the $\mathrm{CO}_2$ content in the atmosphere and thus play a very important role. Sea water contains 50 times more $\mathrm{CO}_2$ than air, ie, about $70 \%$ of total global carbon is found in oceans. This is in the form of carbonates and bicarbonates.