Where do you get the 25x from? Wikipedia says it's 80x-100x:

> over a 20-year period, [methane] traps 84 times more heat per mass unit than carbon dioxide (CO2) and 105 times the effect when accounting for aerosol interactions

(from https://en.wikipedia.org/wiki/Atmospheric_methane)

After that 20 years, methane decomposes into CO2 so its long-term contribution is 3x CO2 equivalent (due to the higher mass after acquiring the oxygen atoms), so its lifetime CO2 equivalence can be higher or lower than 25x depending on which timescale you're looking at. Is the 25x an oft-used figure in the industry/literature?