Roger Caiazza
I am announcing my New Year’s resolution here in hopes of getting feedback and to spur others to provide their resolutions when we hear yet another climate talking point.
When I hear anyone say that methane is more potent than carbon dioxide because the radiative forcing produced is greater, I resolve to say that is only true in the laboratory on a molecular basis. In the atmosphere where it counts methane is not nearly as potent.
Discussion
I have heard the methane scare story all over but my primary concern is New York. As part of New York’s Climate Leadership and Community Protection Act (Climate Act) methane is irrationally disparaged as part of the war on natural gas. The rationale used always revolves around the potency of methane relative to CO2. To respond I have developed a page that consolidates reason why methane should not be vilified. I included the following arguments.
Clyde Spender explained that changes to radiation effects occur on a molecule-by-molecule basis in the atmosphere in an article here titled The Misguided Crusade to Reduce Anthropogenic Methane Emissions. The Climate Act tracks emissions by weight. In the atmosphere CO2 is more than two orders of magnitude more abundant than CH4 on a molecular basis. The Climate Act uses the global warming potential that estimates the mid-range, long-term warming potential of CH4 is 32 times that of CO2. However, that equivalence is for equal weights of the two gases! Using a molecular basis (parts per million-volume mole-fraction) to account for the lighter CH4 molecule reveals that the annual contribution to warming is a fraction of that claimed for CO2. Methane emissions on a molecular basis are increasing at a rate of 0.58% of CO2 increases. Therefore, changes in methane emissions have insignificant effects.
Andy May’s excellent summarization of Wijngaarden and Happer’s important paper “Dependence of Earth’s Thermal Radiation on Five Most Abundant Greenhouse Gases” takes a slightly different approach. He explains that the greenhouse effect of methane is not only related to the effect on longwave radiation itself but also the concentration in the atmosphere. Because the atmospheric concentration of methane is so small doubling concentrations change the “outgoing forcing by less than one percent”. In other words, doubling emissions or cutting emissions in half of methane will have no measurable effect on global warming itself.
Ralph B. Alexander describes another molecular consideration ignored in the Climate Act. Each greenhouse gas affects outgoing radiation differently across the bell-shaped radiation spectrum One of the reasons that CO2 is considered the most important greenhouse gas is that its effect coincides with the peak of the bell shape. On the other hand, the effect of CH4 is down in the tail of the bell shape. As a result, the potential effect of CH4 is on the order of only 20% of the effect of CO2.
The residence time of the two gases is different. Methane only has a lifetime of about 10-12 years in the atmosphere. The “consensus” science claim is that 80% of the anthropogenic CO2 emissions are removed within 300 years. (Note however that there are other estimates of much shorter residence times.) This means that CO2 is accumulating in the atmosphere. CH4 is converted to CO2 and is then counted in the monthly CO2 measurements as part of the CO2 flux. Because methane does not accumulate the same way as CO2 it should be handled differently. However, the Climate Act doubles down. Climate Act authors claimed it was necessary to use 20-year global warming potential (GWP) values because methane is estimated to be 28 to 36 greater than carbon dioxide for a 100-year time horizon but 84-87 greater GWP over a 20-year period.
Conclusion
I would love additional arguments why methane is not to be feared, would appreciate any corrections to my arguments, and would like to hear ways to edit my resolution for more impact.
It would also be useful to me and probably others if WUWT readers would provide similar resolutions for publication.
Happy New Year
Roger Caiazza blogs on New York energy and environmental issues at Pragmatic Environmentalist of New York. More details on the Climate Leadership & Community Protection Act are available here and an inventory of over 370 articles about the Climate Act is also available. This represents his opinion and not the opinion of any of his previous employers or any other company with which he has been associated.
Here are some high-resolution spectral numbers posted by Bones here at WUWT 9 1/2 years ago.
LINK
Cross sections for CO2 in cm^2 per molecule
http://vpl.astro.washington.edu/spectra/co2pnnlimagesmicrons.htm
Cross sections for CH4 in cm^2 per molecule
http://vpl.astro.washington.edu/spectra/ch4pnnlimagesmicrons.htm
Cross sections for H2) in cm^2 per molecule
http://vpl.astro.washington.edu/spectra/h2opnnlimagesmicrons.htm
For well mixed atmospheric gas constituents, the fraction of beam absorption per meter of gas column by each type of molecule at a given wavelength will be proportional to the molecule’s cross-section at that wavelength and also proportional to the number of molecules of that type. These have to be summed over the earth surface thermal emission bands in order to see which molecules absorb the most energy. Water vapor, because of its great numbers of molecules is dominant, but there is significant absorption by both CO2. The low numbers of CH4 result in much less energy absorbed by it. It has a fair sized cross-section but very low numbers.
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Here are some additional links to comments in the 9+ year old thread to read as some are from a scientist such as atmosphere chemist Phil who cautions that high resolution numbers show that water vapor doesn’t cover all of CH4 bandwidth.
LINK Willis Eschenbach
LINK Ken Gregory
LINK PHIL
LINK George E. Smith
Story tip…
Spain’s Socialist Government Confirms Nuclear Plant Phase Out Will Begin In 2027 – Climate Change Dispatch
Maybe they will get their night-time electricity from solar… like they did at one stage.
They recently added a 7th LNG terminal at Gijon to the existing ones at Bilbao, Murgados, Huelva, Escombreras, Sagunto and Barcelona. Regularly seeing Russian LNG discharges at all ports (perhaps Europe’s biggest Russian LNG customer at the moment), although they do get supply from other sources too.
Joseph,
New York’s Climate Act is political policy at its worst. New York regulates its GHG emissions using GWP-20 because of methane and that is directly a result of Howarth. The legislators who authored it relied on the scientific input of Robert W. Howarth, Ph.D., the David R. Atkinson Professor of Ecology & Environmental Biology at Cornell University who has claimed authorship of the methane portions of the Climate Act. I have never seen any indication that he is aware of my skepticism and I doubt that he would acknowledge anything I have written. I don’t think he has much background in atmospheric physics and, frankly, I doubt he would ever try to understand all the arguments described here.
I have submitted comments on regulations and reports arguing that methane is not an issue, There has never been a substantive rebuttal to those comments. Technical staff at the agencies have their hands tied because Howarth got a lot of the methane crap into the Climate Act law. There is no room for skepticism in the agencies so they just toe the line and ignore my comments,
As you say no expression of official doubt is acknowledged, tolerated, or allowed to upset the narrative. I should note that there are some politicians, even a few Democrats, that have figured out that there problems with the Climate Act.
Roger
This was supposed to be in response to Joseph Zorin at December 29, 2023 2:34 pm
Worth pointing out that Wijngaarden and Happer produced a separate paper concentrating specifically on methane, available here:
https://co2coalition.org/publications/methane-and-climate/
Great reference – thanks
Actually, I’m usually rather frugal. 🙂
Roger, trees emit methane and in the bark, colonies of symbiotic bacteria eat methane for their life energy and mass. They break carbon-hydrogen bonds with an organic chemical in ther bodies. Apparently they consume about 50% or so of emitted methane. This is a huge! It was discovered over a hundred years ago and little research had been done so far.
https://news.northwestern.edu/stories/2022/03/methane-converting-bacteria/
PThe “huge” part is this: alarmists claim that 60% of methane emissions are due to human actions. Since they are not aware that trees emit the gas, then, with over 3 trillion trees on earth (counted by Google over 10yrs ago) and growing, forests, bogs and swamps, beaverponds, natural seeps, etc., have to be responsible for a huge percentage of the methane in the atmosphere! Indeed, with forests having expanded over 35% in the last 40yrs, it probably accounts for the growing emissions (agriculture has more than doubled output on about 20% less land (gone into new bush)
All living things emit methane. Who knew? Maybe expanding habitat, diversity and the creatures and trees is not a good thing if you’re from the Dark Side!
It wasn’t so long ago that termites were considered to be one of the top two methane producers. Now, they are rarely mentioned.
Not to mention that the amount is so tiny it can barely be measured and something that tiny cannot affect anything let alone something so vast and complex as the climate
The new methane regs are just another chapter in the ever-thicker Democrat playbook for domestic oil and gas harassment. The regulators know it, the industry knows it, anyone paying attention knows it, and the eco-cult and their Chinese supporters know it and love it.