CO2 is carbon dioxide.
And CO2 and all plays a part in the greenhouse effect, warming the Earth's surface, keeping the temperature perfect for all living things. That's why CO2 is called the "greenhouse gas."
However, if there is too much of this "greenhouse gas," the whole Earth's temperature gets too high and it causes big problems for living things. So, if we want to help wildlife, we must make efforts to reduce our use of CO2.