NOS and CO2 are very different. NOS is referring to nitrous oxide which is N2O or two Nitrogen atoms and an oxygen atom. CO2 is a carbon attom and two oxygen atoms.
Furthermore, the way that these two molecules (CO2 & N2O) behave is very different. Though CO2 easily dissolves in water when under pressure (such as in soda or carbonated drinks like lemonade), N2O readily dissolves in fat when under pressure. This is why N2O (nitrous oxide) is used to whip cream (cream with a high fat content) as the N2O from a nitrous oxide cream charger dissolves into the fat when in the whipped cream dispenser where it is under pressure and then when the cream is released from the dispenser into a lower pressure it expands inside the cream fat and ‘whips’ the cream making it light and fluffy.