Pass papers 2014 #4
a) with the aid of a diagram outline 3 processes which return carbon to the atmosphere and 1 which removes (include the form in which carbon is formed in the atmosphere).

Carbon is returned to atmosphere by processes like respiration, decaying and burning. It's absorbed from atmosphere by processes like photosynthesis.

Explanation:

Carbon cycle is a diagramatic approach to explain how the mass of carbon is distributed in our atmosphere, biosphere and earth, and how the cyclic processes run to exchange the carbon mass between themselves.

As far as the pool is concerned, carbon is present as carbon dioxide in the atmosphere. Its from where the carbon is taken from, or is deposited into. Carbon dioxide is given off into atmosphere by means of respiration. Its contributed by each and every living creature which are aerobic and take in oxygen releasing carbon dioxide into the atmosphere. Next process is decaying of organic matters by bacteria and other microorganisms which release carbon dioxide into air. The third process is burning of fuels which releases carbon dioxide and Carbon monoxide into air.

There are several processes by which carbon dioxide is absorbed into the system from atmosphere. One and the most important of them is photosynthesis. This process absorbs carbon dioxide to produce glucose and other organic matters that are then consumed by the whole biosphere as food.