Human additions of CO2 are in the margin of error of current measurements and the gradual increase in CO2 is mainly from oceans degassing as the planet slowly emerges from the last ice age.
Atmospheric CO2 has increased rapidly as a result of human activities. Although human-caused emissions of CO2 are small relative to natural flows into and out of the atmosphere, the human contribution has caused an imbalance in the global carbon cycle that jeopardizes land and ocean ecosystems.