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The logarithmic forcing relation implies decreasing incremental forcing per additional ppm, explaining the two annual-increment results. It does not imply that a higher total carbon dioxide burden requires less compensation relative to a fixed original climate. The chosen reference and whether an end-of-year, mean-year or steady maintained aerosol burden is intended must remain explicit.

The numerical mass estimates use an unusually simple, stipulated constant albedo-per-mass calibration. Real particle size and lifetime change with loading, aerosol coagulation, injection altitude/latitude and circulation. Sulfate absorbs radiation as well as scattering it and changes stratospheric chemistry. A global-mean shortwave/longwave radiative forcing balance also need not reproduce regional temperature, rainfall or transient ocean heat uptake; it does not undo CO2-driven acidification. Chemistry–climate simulations explicitly resolve some of these competing aerosol-size, temperature and ozone effects.^[ref]

P. Heckendorn coauthored coupled aerosol and chemistry-climate simulations of stratospheric aerosol injection. The study examines effects on stratospheric temperature and ozone, rather than treating injected mass as a fixed amount of cooling.

Particle growth changes scattering and settling, while temperature and chemical changes affect ozone. These coupled responses explain why aerosol amount alone does not determine the climatic outcome.^[ref]