Question

What is the cause for fluctuation of carbon concentrations in short term and long term carbon cycles?

Answer 1

If the amount of C14 in a given amount of carbon (C12) has changed in a particular time period has changed then the results of carbon dating would change, One would have to examine the reasons for changes in the amount of C14 present in a given amount of C12.

Answer 2

Answer: Much of this variation happens because of the role of plants in the carbon cycle

Explanation:

The amount of CO2 found in the atmosphere varies over the course of a year. Much of this variation happens because of the role of plants in the carbon cycle. ... Respiration occurs all the time, but dominates during the colder months of the year, resulting in higher CO2 levels in the atmosphere during those months.