would also be interesting to see the methane concentrations in that context.
writes on that:
>Methane is created near the Earth's surface, primarily by microorganisms by the process of methanogenesis. It is carried into the stratosphere by rising air in the tropics. Uncontrolled build-up of methane in the atmosphere is naturally checked — although human influence can upset this natural regulation — by methane's reaction with hydroxyl radicals formed from singlet oxygen atoms and with water vapor. It has a net lifetime of about 10 years, and is primarily removed by conversion to carbon dioxide and water.
where  is:
Boucher, Olivier; Friedlingstein, Pierre; Collins, Bill; Shine, Keith P (2009). "The indirect global warming potential and global temperature change potential due to methane oxidation". Environmental Research Letters 4 (4): 044007. Bibcode 2009ERL.....4d4007B. doi:10.1088/1748-9326/4/4/044007.