What are the two ways that carbon enters into the atmosphere?

Animals and plants need to get rid of carbon dioxide gas through a process called respiration. Carbon moves from fossil fuels to the atmosphere when fuels are burned. When humans burn fossil fuels to power factories, power plants, cars and trucks, most of the carbon quickly enters the atmosphere as carbon dioxide gas.

Animals and burning fossil fuels

Explanation:

animals need to get rid of carbon through respiration

carbon emissions are a byproduct of burning fossil fuels and other organic matter