Subhadrika Sen
Afforestation: Those plant-a-sapling and afforestation drives that are held often is key in restoring oxygen balance in the atmosphere.
Stop felling of trees: Go digital if you have to! But the more trees you cut, the lesser oxygen you have in the air.
Switch to non-polluting commute: Cars usually consume fossil fuels, petroleum oil etc which are polluting the air and depleting oxygen. to combat that, one can switch to walking, sharing vehicles, solar / battery powered cars, etc.
Solar -powered panels : Using Solar panels reduced the pressure on carbon usage, giving oxygen levels a chance to flourish in the air.