UNs IPCC Reports https://www.ipcc.ch/site/assets/uploads/2018/03/Chapter-5-Hydropower-1.pdf See fig 5.15. The outliers are the concern (and yes, it's pretty much methane)
Edit: I reread the parent comment, the above won't address what you asked for, but is interesting nonetheless so I'll leave it
Wait, I'm still catching up. Why would it have been illegal?
UNs IPCC Reports https://www.ipcc.ch/site/assets/uploads/2018/03/Chapter-5-Hydropower-1.pdf See fig 5.15. The outliers are the concern (and yes, it's pretty much methane)
Edit: I reread the parent comment, the above won't address what you asked for, but is interesting nonetheless so I'll leave it