Co2 is NOT pollution. It is plant fertilizer.
And it is 1.5x heavier than air. It pools in low areas, get's absorbed by plant life. The reason that you have tree lines in the mountains is because above certain altitudes there is not enough CO2 for trees to grow and above that there are places where nothing grows. Not enough CO2.
The Earth's atmospheric CO2 levels have been on a very long term downward trend. At less than 180ppm we and everything else is toast. CO2 gets sequestered in the ground and thank God humans have come along at just the right time to be able to release enough of it (and gain cheap plentiful energy from it) to save the planet from becoming Mars.
All the Carbon sequestered in the ground used to be in the biosphere when the Earth was not an ice covered, dry, mostly barren planet. The planet was wet and lush with life everywhere. Not a bad place for living things and with carbon based life forms on every inch of the place.
The de-Carbon crowd are the death cult. they want to depopulate the planet and have talked about it for decades. Famines, energy reduction, lower standards of living lead to disease, pestilences and death for billions.