cf. public discussion.

I would like to congratulate and thank the authors on what is a really excellent paper : sound science, clear, rigorous, with convincing supporting references, mathematics (with clear notation), and very good careful graphics. The appendices are also very valuable. No doubt that I will handle the paper both graduate and undergraduate students and recommend it to colleagues.

Below a few outstanding technical suggestions, which the authors may accept or reject:

p. 2 : l. 10 : that CO2-concentrations will -> that CO2-concentration trends (?)

p. 3 : ... and not demonstrated with... -> and not formalised within

p. 4, eq.1, eq.2 : avoid the extra line space in your LaTeX file, in order to prevent paragraph indentation after the equation

p. 6, l. 15 : ... implies for near-surface air : implies for near-surface ($h=0$) air :

p. 6. l. 20 : in reality, the diffusion of heat __and turbulent advection__ remove

p. 6, l. 22 : 'in terms of' (bad usage) -> 'by reference to'

p. 11, l. 22 : This implies that at first the upper half mass of the atmosphere is cooled while... (again, avoid the construction 'in terms of')

p. 11, l. 24 : In _radiative_ equilibrium,...

p. 17, l. 11 : This procedure also suppresses further changes to the surface temperature pattern, contributing among others to polar warming amplification. [sea-ice is not the only mechanism : even an aqua-planet has polar amplification, because of latent heat transport, see works by Pete Langen and V. Alexeev)

p. 20, ll. 19 and 20 : use LaTeX symbol $\times$ for CO_2 $\times$ 2

p. 22, l. 7 : straightforward in one word

... I discovered the words minuend and subtrahend. Well done.

p. 28, last sentence of Appendix C : Do to this non-linear additivity ... (?) (or non-linear additive terms ?)