1.1. The diagram below shows a representation of the carbon cycle.

Explain how carbon is returned to the atmosphere at the stage labelled Y.

1.2. The diagram in part (a) is missing many details of the carbon cycle.

Label the diagram as follows to show where each of the processes occurs within the carbon cycle. 

(i) Use the letter R to show where respiration occurs.

(1)

(ii) Use the letter P to show where photosynthesis occurs.

(1)

(iii) Use the letter F to show where feeding occurs.

(1)

1.3. Carbon from fossil fuels enters the atmosphere during combustion.

(i) Explain how this process contributes to rising average global temperatures.

(2)

(ii) Explain how cutting down trees during deforestation increases the problem described in part (i).

(1)