Radiative Forcing of Methane in Shortwave

[Graeme M]

I was doing some reading about the extent to which methane absorbs in bands already dominated by water vapour and came across this paper. Two things stand out for me - first is that according to the authors the RF of methane is increased by 23% due to previously underconsidered shortwave absorption, and secondly their observation (in section 3.4 Uncertainties) that assuming zero aerosols (and therefore lowered albedo) results in a reduction in shortwave forcing of 10%.

Does anyone know if the authors' revised calculations have been agreed? Also, am I correct to think from this that higher aerosol concentrations would lead to increased shortwave forcing of CH4? Would that suggest that higher aerosol concentrations in the recent past (mid 20th century) would have contributed to larger total RF from greenhouse gases than has been thought? I had previously read (I think) that high aerosol concentrations had limited the rate of atmospheric warming.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL071930

 

[jim mcnamara]

This is not my area. But. The paper you linked to has a nice feature called "cited by". In this case there is a number "91". This shows papers that cite, or "followup" on the paper you read. Click on the "91". You might see something useful.

Quite honestly some of the mentors have read the paper. Because of the way the authors seem to abbreviate two terms as "RF", we have trouble understanding things: RF as in shortwave and RF as in radiative forcing. Maybe we are totally off. Won't be the first time.

So I'm going to ping @Genava, who has a better understanding, and let's see what we get.

 

[Graeme M]

Thanks Jim. Looking at some of those references indicates this paper has been accepted (for example, one paper notes that the authors "...use the latest well-mixed greenhouse gas (WMGHG) radiative forcing (Etminan et al. 2016; Meinshausen et al. 2017) "