What are the factors affecting production of CO2 and uptake O2 in non – humans?

By "non-humans", I assume you mean life forms other than human beings, such as plants and animals. Aerobic life forms consume oxygen and produce carbon dioxide during the process of aerobic respiration. In this process, food substrate (such as glucose, proteins, etc.) is broken down, and carbon dioxide and energy molecules are generated. An example is the breakdown of glucose, as shown by the following chemical reaction:
C_6H_12O_6 +6O_2 -> 6CO_2 + 6 H_2O + ATP
ATP molecules represent the energy.
One of the factors affecting the production of CO2 and uptake of oxygen is the food substrate, since each substrate may have a different ratio of carbon to oxygen and hence a different amount of oxygen may be used and a different amount of CO2 may be generated. Temperature is another factor that can modify the rate of oxygen uptake and CO2 generation, since higher temperature means a faster rate of reaction. Similarly, lower ambient temperatures mean lower rates of reaction. The energy needs of the organism will also dictate the amount of oxygen consumed and CO2 produced, since a higher exertion level requires more energy. The availability of CO2, oxygen, light, etc., may also affect the oxygen uptake and CO2 production. For example, higher CO2 levels cause lower rates of aerobic respiration.
Hope this helps.