Select the appropriate option regarding forest conservation.

Which energy source does not release $CO_2$?

Select the correct option for 'Ecosan'.

Choose the correct option regarding the following statements:
$(1)$ $CO_2$ contribution in global warming is $60\%$.
$(2)$ Greenhouse effect occurs due to deforestation.
$(3)$ Due to the greenhouse effect,the present average temperature at the surface of the Earth is $15^oC$.
$(4)$ The amount of $DDT$ in small fish is $0.05\ ppm$.

Which one of the following pairs is mismatched?

What is found in photochemical smog?