Final answer:
The carbon cycle involves the entry of carbon dioxide into the atmosphere through burning of fossil fuels and its absorption by plants through photosynthesis. The stored carbon is released back into the atmosphere over time through natural processes or human activities. The use of carbon through burning fossil fuels and deforestation contributes to the increase of carbon dioxide in the atmosphere.
Step-by-step explanation:
In the carbon cycle, carbon dioxide enters the atmosphere through the burning of fossil fuels and is taken up by plants through photosynthesis. The carbon is then cycled back into the atmosphere through respiration. Long-term storage of carbon occurs when organic matter is buried underground and becomes fossilized. This stored carbon can be released back into the atmosphere through volcanic activity and human emissions.
a. The sink and store cycle of carbon dioxide do not occur in equal amounts of time. It takes a relatively short time for carbon dioxide to enter a sink (such as plants) through photosynthesis, but it can take much longer for the stored carbon to be released back into the atmosphere through natural processes or human activities.
b. Our use of carbon through the burning of fossil fuels and deforestation increases the amount of carbon dioxide in the atmosphere. This is because when fossil fuels are burned, they release carbon dioxide into the atmosphere, and when trees are cut down, they are no longer able to absorb carbon dioxide through photosynthesis.