[RinaseaofDs]

The molar mass of H2O is less than the molar mass of O2, which is less than the molar mass of CO2. Unless that changes, CO2 isn’t going to trap heat in the atmosphere.

It will continue to help plants develop in the ocean.

That was the point.

[alexander_busek]

The molar mass of H2O is less than the molar mass of O2, which is less than the molar mass of CO2. Unless that changes, CO2 isn’t going to trap heat in the atmosphere. It will continue to help plants develop in the ocean. That was the point.

Don't understand: Why should CO₂ being heavier than air in any way influence its action as a greenhouse gas?

H₂0 (water vapor) is lighter (less dense) than N₂ (constituting 78% of the atmosphere), which in turn is lighter than O₂, which in turn is lighter than CO₂.

So what? The concentrations of these gases does not vary significantly with respect to altitude (at least, not for several hundred kms). The atmosphere is remarkably well mixed.

So what does the density of carbon dioxide have to do with it being a greenhouse gas?

Regards,