The numerator integral must decline rapidly as a function of TH unless the radiative efficiency is a strong function of time, which seems unlikely. Most of the

The numerator integral must decline rapidly as a function of TH unless the radiative efficiency is a strong function of time, which seems unlikely. Most of the actual warming effect of a methane release would occur in the first three decades, after which there would be a long tail of slight warming. Methane is not irrelevant, but "global warming potential" seems to obscure the actual time varying nature of the relative impacts. Methane is actually a much stronger greenhouse gas than carbon dioxide in the short run and less strong in the long run that global warming potential would indicate.