Volcanic activity puts a great number of gaseous materials into the atmosphere so any warming as a result of severe volcanic events would be more likely a result of increasing
overall atmospheric density rather than just being attributable to CO2 emissions.
The only things that can change that resultant point of temperature equilibrium significantly are changes in solar radiance coming in and changes in
overall atmospheric density (a function of mass and pressure) which affect the radiant energy going out or a change in the speed of the water cycle which, because of the unique characteristics of the phase changes of water altering the speed of energy flow through the system is capable of exerting a powerful regulatory effect.
The speed of release is again dictated by
overall atmospheric density because greater density renders it less likely that the neighbouring molecules are cool enough for a release of radiant energy to occur.
On Earth the proportion of CO2 is so small that it can not affect
overall atmospheric density even if it increases by many multiples of the current level.
The only things that can change that resultant point of temperature equilibrium are changes in solar radiance coming in or changes in
overall atmospheric density which affect the radiant energy going out.
i) CO2 and other trace gases are too small a proportion of the atmosphere to make a significant difference to
overall atmospheric density even if their volumes were to be multiplied many times over.