Answer: The net flux of carbon into the atmosphere without including the contribution from burning fossil fuels is positive.
Step-by-step explanation:
The human activity of burning fossil fuels inevitably contributes to the increase in carbon dioxide and other gases in the Earth's atmosphere. As a result of this occurrence, a natural greenhouse appears. The greenhouse effect is the process of warming the Earth's surface and the lower layers of the atmosphere, resulting from the leakage of heat radiation.