Wednesday, 7 December 2022



How much methane is likely to be released by the melting of permafrost due to Global warming, and what are the likely impacts of this (how bad will the effects be)?

The IPCC exaggerate everything and so don’t take this post as anything remotely truthful, but let’s just see how much methane (CH4) is expected to be released from the melting permaforst, based upon the IPCC’s own figures. In AR5 2013, the IPCC give an estimate of 5 PGs of released methane from permafrost by 2100 (source: IPCC AR5: Biogeochemical Cycles, page 530 to 531). PGs is equivalent to gigatonnes (Gts). See the extract below taken from the link and page above in the IPCC’s report. Now, 5 Gts of CH4 works out at about 1.9ppmv or 1900 parts per billion (ppb) and so 1 Gts of CH4 is equivalent to 0.38ppmv. So, how much effect would this extra 5 Gts of CH4 have? Would it be catastrophic?

Click on image to enlarge.

The formula below can be used to determine how much radiative forcing a given increase in CH4 would have. Where ΔF stands for the ‘increment of radiative forcing’ in W/m²; M is the new CH4 concentration in ppb after the increment is added, and M₀ is the old CH4 concentration before the increment was added.

Accepting that the current CH4 concentration is about 1900ppb (as of 2019) and that the IPCC say another 1900ppb will be added to the atmosphere by 2100 due to the melting permafrost (total of 3800ppb) then that would give us a radiative forcing from the released CH4 of 0.036(38001900)=0.65W/m² which would only be enough to raise the surface temperature by 0.12°C. And that is on the basis of their own figures and formula! It makes you wonder how people can continue to justify ‘the sky is falling’ hysteria about CH4.

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