The reduction of the carbon-dioxide would be even more gradual.
Then air-rejuvenator apparatus reseparated it from the carbon-dioxide you exhaled, so that you could use it over and over.
A part is expelled by the lungs as carbon-dioxide, or as it is generally though less correctly termed, carbonic acid.
Every molecule of carbon-dioxide that crystallized out took two atoms of oxygen with it, completely out of circulation.
In the form of carbon-dioxide the leaves eat up the carbon and oxygen from the atmosphere.
The warmth and the habitability of the earth's surface is due to the presence of water-vapor and carbon-dioxide in the atmosphere.
They contained a carbon-dioxide cartridge and could be inflated simply by squeezing them, which punctured the cartridge.
Depressions in the carbon-dioxide snow where the hundred-foot pad-feet of ships' landing-legs had pressed down.
But the planetesimal hypothesis has no room for this enormous percentage of carbon-dioxide in the primitive atmosphere.
Whatever excess of carbon-dioxide there may have been in the early atmosphere was cleared by the Coal-forests.