The majority of carbon dioxide produced by our body cells is transported to the lungs -

$CO_2$ is carried by the blood in three forms.
About 70 percent is carried as bicarbonate.
About 20 to 25 percent is carried by haemoglobin as carbamino-haemoglobin.
About 7 percent is carried in a dissolved state in the plasma.
At the tissues, $CO_2$ diffuses into the red blood cells, where the enzyme carbonic anhydrase catalyses the reaction $CO_2 + H_2O \rightleftharpoons H_2CO_3 \rightleftharpoons HCO_3^- + H^+$
In the alveoli, where the partial pressure of $CO_2$ is low, the reaction proceeds in the opposite direction and $CO_2$ is released.
So the majority of the carbon dioxide is transported as bicarbonates.