If total CO2 in the atmosphere were at equilibrium (it is not currently), there would also be a mean amount of time for CO2 to be sequestered. The ratio of (mean CO2 time / greenhouse breakeven time) would exactly characterize how much worse for the climate energy sources with carbon emissions are relative to zero carbon sources in terms of the total contribution of heat into the environment. With CO2 not at equilibrium, there is probably some fancier model to get a similar characterization.
Finally, it would be interesting to see quantification of different sources of renewable power in terms of thermodynamic impacts. For example, I would expect that solar would lead to energy that would otherwise likely be reflected back to space instead be dissipated into heat. It would probably for example be worse to have a planet that is entirely covered with black solar panels from a radiation perspective. On the other hand, for something like hydroelectric or geothermal, it would seem like we are simply channeling a energy source that is already just about to be dissipated into heat on its own.