Question

Carbon dioxide is necessary for plants. Why do we consider it as a pollutant? [2 Marks]

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.
[1 Mark]
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.
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