Question

Question 56
Carbon dioxide is necessary for plants. Why do we consider it as a pollutant?

Answer 1

Carbon dioxide is necessary for plants for the process called photosynthesis. This process converts carbon dioxide from the atmosphere or dissolved in water into glucose molecules. But increasing concentration (more than normal) of $C{O}_2$ is harmful and considered as a pollutant. Because it absorbs and retains heat very well, and can, therefore, contribute to the greenhouse effect, which is basically global warming.