=> First celebrated world environment day in 1974 with the theme of "Only one Earth".

=> Atmosphere: Air and currently 20.94% of the oxygen available on earth.

=> Drinkable water level only 2.5% available on earth.

=> Natural environment and human relationships are important and in between balancing are most impotent. 

=> WHO divided 3 types of human and nature 1. Physical 2. Mental 3. Social 

=> Effective factors over-population, pollution, burning fuels,  and deforestation.

Our responsibility to use reusable natural resources and how we can overcome to use.