Question

$C{O}_2$ is necessary for plants. Why do we consider it as a pollutant?

Answer 1

Though CO2 is necessary fro plants, it is considered as a pollutant because carbon dioxide is a green house gas and its excessive amount in the atmosphere results in global warming.

Higher concentration of carbon dioxide may cause suffocation, choking in humans. It increases the overall temperature of the earth, which has lead to the changes in the earth’s climate.