Task: Sentence Ordering
Input (English): Steps: (1) Solar radiation reaches Earth's atmosphere (2) Some is reflected back into space (3) The rest of the energy is absorbed by land and oceans, heating the Earth (4) Heat radiates from Earth to space (5) Some of this heat is trapped by greenhouse gases in the atmosphere (6) This causes more heat radiation to stay trapped in our atmosphere (7) The Earth's temperature rises  
Where does the following step fit into the given list of steps: Human activities such as burning fuel are increasing the amount of greenhouses gases 
Output (English):  After step 5.