How is excessive content of `CO_(2)` responsible for global warming ?

Explanation

During combustion, `CO_(2)` is produced. It is used by plants during photosyntheses and `O_(2)` is released in the atmosphere.As a result of this `CO_(2)` cycle, a constant percentage of `O_(2) (21%)` is meantained in the atmoshere. However, if the concentration of `CO_(2)` increases beyond a certain level due to excessive combustion, some of the `CO_(2)` will always remain unutilised. This excess of `CO_(2)` absorbs heat radiated by the earth. Some of it is dissipated into the atmosphere, while the rest is radiated back to the earth and other bodies present on the earth. As a result, the temperature of earth and other bodies on the earth increases. This is called greenhouse effect and `CO_(2)` is called a greenhouse gas. As a result of greenhouse effect, global warming occurs which has serious consequences.