By Paul Homewood
https://www.bbc.co.uk/news/science-environment-60203683
The BBC article on methane makes an interesting claim:
An IPCC study last year suggested that 30-50% of the current rise in temperatures is down to methane.
The study referred to is AR6, which estimates that increased levels of methane in the atmosphere have contributed 0.5C to global warming since 1850-1900:
https://www.ipcc.ch/report/ar6/wg1/
Given that even IPCC reports have accepted that some of the warming since the 19thC has been naturally caused, that does not leave much which can be due to CO2.
Even without taking those natural factors into account, net of aerosols only about 0.6C of warming is man-made, once methane is excluded from the equation:
It therefore seems that CO2 is a vanishingly small problem.
Methane, which is 84 times as powerful as a GHG per unit than CO2, has an extremely short life span, declining in the atmosphere by half every decade.
Consequently we don’t have to start drastically reducing emissions now. Merely maintaining current emissions will mean that atmospheric concentrations will level off quickly:
Indeed, if the current push to cut methane emissions is successful, we would likely see rapid global cooling, assuming of course the IPCC calculations are right.
Given the reactions of the world’s leaders and scientists in the 1970s following three decades of global cooling, that might not turn out to be such a clever idea at all!
FOOTNOTE
I should point out that some scientists believe that methane is virtually irrelevant as a GHG, because its emissions spectrum is already fully filled by water vapour.
See here.
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February 5, 2022 at 06:33AM
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