Excessive release of $\mathrm{C}{\mathrm{O}}_2$ into the atmosphere results in

Carbon dioxide is very important for maintaining the climate which is suitable for our survival.
${\mathrm{CO}}_2$ has the property of trapping heat from the sun. So higher the level of carbon dioxide, the higher will be the heat trapped. This leads to the rise in the temperature of the earth, resulting in global warming.Therefore, we can say excessive release of ${\mathrm{CO}}_2$ into the atmosphere results in global warming.