CENTRAL Queensland cattle producer and grazing consultant Mick Alexander has regularly raised questions in response to Beef Central articles reporting that it takes 10 to 12 years for methane emissions to break down in the atmosphere.
Pointing to online videos of presentations given in recent years by ex-CSIRO scientist Walter Jehne, Mr Alexander says the science shows that methane emissions from cows are naturally broken down as soon as they are released from cattle by hydroxyl ions.
Mr Alexander said that despite conducting research for several years he has been unable to find scientific evidence that definitively proves the length of time it takes methane to break down into carbon dioxide.
“It was first mentioned about two decades ago in literature but without any validation as to who or how it was proven – no scientist has been able to show the science,” he said.
In response to Mr Alexander’s inquiries we have asked a number of scientists and experts in the methane emissions field if they can point us to the original scientific research definitively proving that it takes 10-12 years for methane to break down.
Very few of those we have contacted believe there is any dispute that it takes up to 12 years for methane to break down in the atmosphere.
However, while some have pointed to existing studies or webinars that repeat the position that it takes in the order of 10-12 years for methane to break down, examples of the original scientific studies proving the exact claim have not yet been forthcoming.
Many responded with their scientific reasonings to support the 10-12 year breakdown position, which are outlined below.
Their responses also highlight variation in scientific views around questions such as how long it takes for methane to break down and the effect methane emissions from livestock have on atmospheric warming.
If any scientists reading this article can shed further light on this issue and help to put this question to rest, we welcome your contributions in the comments box below.
Mick Alexander says gaining a clear understanding how the often-quoted 10-12 time frame was arrived at is important because the 10-12 year time frame that the powerful greenhouse gas methane remains in the atmosphere is a fundamental component of calls to curb livestock production.
Hydroxl ions ‘have methane for lunch’
In the above video of a 2020 presentation made in New Zealand, ex-CSIRO scientist Dr Walter Jehne outlines his evidence-based reasoning to explain why livestock should be considered a vital part of the solution to managing atmospheric methane levels.
Livestock – or “mobile biodigesters” – play an important symbiotic role in managing green growing pastures and causing them to transpire water molecules, he explains in the video.
When sunlight hits the water molecules photo oxidisation turns them into hydroxyl ions (along with hydrogen ions) which are the “laundry of the air”.
“That is what cleans up the air, they’re free radicals.. they really gobble up pollutants, – polyaromatic, hydrocarbons, particulate carbons – they are the things that clean up the air big time and of course these guys have methane for lunch, no troubles.”
A cow grazing and maintaining a green pasture that is transpiring will produce 100 times the methane free radicals that it needs to oxidise the methane it produces, he said.
“So when they come and want you to pay for methane emissions for your cattle, you have got to pay that.
“But attached to your cheque for the payment, you have got to attach an invoice, and that invoice is for your cow’s management of grasslands to photo oxidise all the other crap that is going up in the air.
“So you have got to send an invoice to the Government to say, right, yes here is my dollar for my methane and here is my $99 claim for photo oxidisation.”
Dr Jehne said that despite there being large populations of methane-emitting herbivores on the planet including bison, antelope and wildebeest, atmospheric methane levels remained steady at 700 parts per billion for the past million years, thanks to this balancing process.
He said recent rises in atmospheric methane levels in recent decades are attributable to fugitive emissions from mining which followed the collapse of the Soviet Union in 1990 and an abandonment of wells, and the introduction of fracking techniques to free up coal seam gas since 2010.
Methane trapped in continential ice shelves a key concern
In another presentation he has also stated that his biggest concern (from 1:29:38 mark of video) relating to methane is that global warming will continue to release huge volumes of methane currently trapped in continental ice shelves.
“There is about 15,000 billion tonnes of methane locked up in methane hydrates on the continental shelves,” he said
“This is methane effectively as ice crystals and as the oceans warm basically a lot of that has already been releasing.
“If we get a massive release of that methane it is game over higher life. It has happened previously, it is a extinction event.
“And the only thing that is going to save the earth potentially from one of these mass methane extinction events, the only thing that can save the earth is have we got enough green actively transpiring pastures at higher latitude maintained by caribous, reindeer, herbivores to give you enough of this photo oxidisation to neutralise that extinction risk.
“So we have an extinction risk and the question is have we got enough hydroxyl radical from these pastures to neutralise (it).”
Responses from scientific sources
As referenced earlier, Beef Central has previously asked several scientists around the world and people with expertise in methane emissions from livestock for their views on how long it takes for methane to break down.
Summations of the key points they provided in response include:
“Hydroxyl radicals do breakdown methane but only when it gets to the upper atmosphere, because that’s where most are formed by the interaction between ozone and water vapour.
“The idea that it’s broken down immediately is wrong – firstly, as they are not produced in the same place and secondly, hydroxyl radicals are used to scrub more than just methane (methane, sulphur dioxide, carbon monoxide, nitrogen oxides and other organic compounds), but the production is fairly constant in the upper atmosphere, which means if we produce more methane than pre-industrial we run out of hydroxyl radicals to cope with the methane (there are even reports of a hole in the upper atmosphere where there is no hydroxyl radicals anymore).”
“Some people have promoted the theory that soil organic matter can produce hydroxl radicals. Hydroxyl radicals can be generated in soils mediated by oxidation of ferrous iron and/or microorganisms and can then oxidize dissolved organic carbon to carbon dioxide.
“BUT technically this also means the more hydroxyl radicals produced by our soils the more we accelerate decomposition of soil carbon (in humid environments) and release CO2.On average it takes about 10-12 years before a methane molecule makes contact with a OH radical in the atmosphere. To say breaks down instantaneously misses the full story.”
“Methane does break down immediately when it makes contact with a OH radical in the atmosphere. But, that is only part of the story. On average it takes about (with the emphasis on about) 10-12 years before a methane molecule makes contact with a OH radical in the atmosphere.”
“Yes methane breaks down under the action of Hydroxyl ions (the “chemical” pathway listed in technical descriptions of the process). Some of these Hydroxyls may be generated indirectly from transpiration of pastures, but this process is diffuse and takes some years to occur in the atmosphere. The best estimate currently from the IPCC is 11.8 +/- 1.8 years.”
The Climate Media Centre also provided a detailed response to Beef Central questions, replying that it had asked Farmers for Climate Action and experts at the Climate Council and was told there is no such thing as instant absorption/breakdown of methane. “And even if methane was able to break down super fast, we’ve now got so much of it in our atmosphere that it’s playing a key part in warming our planet.”
The Climate Media Centre’s response continued:
“There are some differences in methane produced by livestock and rice paddies (biogenic methane) and methane dug up for burning as fuel. And that is to do with fossil fuel methane adding carbon into the atmosphere overall after it breaks down; livestock burps don’t do that, but that’s a long term thing which confuses a lot of people. The key thing experts say is that methane has a heating effect, regardless of the source.”
Mark Howden and Richard Eckard did a recent webinar with Farmers for Climate Action:
Methane & Global Warming Potential Webinar – 9 Nov 2023 (youtube.com)
The break-down times for biogenic methane are addressed about 12:45 in and 15 minutes onwards.
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- They explain that methane has a half life of 11 years so half of it breaks down within 11 years. It’s definitely not all gone immediately.
- Mark Howden explains that biogenic methane (methane from cattle and rice paddies) does behave differently in the atmosphere to industrial methane dug up from the ground. The carbon atoms in methane from cattle are not adding more carbon to the ‘active’ carbon cycle in the way that burning fossil fuel methane does. But that is over an entire life cycle.
- Also in the webinar the scientists explain the really key thing for the climate is that it’s not so much about the chemical composition as the heating effect of these gases. (The heat is mostly absorbed by the ocean, and warmer oceans play havoc with all our weather / climate systems.)
There’s a blog about methane which explains why there’s so much confusion about the numbers:
https://climateer.substack.com/p/methane-lifetime
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- This blog says that on the breakdown times, everything breaks down over time and the half-life of methane is around 8 – 10 yrs meaning it is all mostly gone by 12 yrs.
- A chunk of the methane does get broken down initially but it takes longer and longer for the rest of it.
- The more methane we have in our atmosphere, the more this whole process slows down.
The Journal Nature
https://www.nature.com/articles/d41586-021-02287-y‘
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- The journal article points out that there are some uncertainties about exactly how much methane is about and where it’s coming from
- It points out many steps we can take to reduce methane would save money, including capturing methane that escapes from gas plants and coal mines, landfill and wastewater plants, and adjusting rice farming practices. These would have a big impact and give more time to find solutions for emissions from the cattle/meat industry.
This article in the Conversation
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- “Fully considered using the 100-year GWP and including natural feedbacks, the IPCC’s reportsays fossil sources of methane – most of the gas burned for electricity or heat for industry and houses – can be up to 36 times worse than carbon dioxide. Methane from other sources – such as livestock and waste – can be up to 34 times worse.”
The United Nations Environment Program explains methane here:
Have a view or any thoughts to share? Let us know in the comments box below.
Those who object to mineral methane seem to have forgotten that oil, gas and coal came from buried plant material. So any methane emanating from these billions of tonnes of buried plant matter must be in a chemically compatible form for use by plants today when released and burnt. Hydrogen (heat) and water are released by-products along with C and CH3. Those buried billions of tonnes of plant material logically once survived in a beneficent earth climate for their proliferation and reproduction.
The question is, would the plant-dominated climate they lived in be hostile to or convivial to man? The carbon cycle it produces would have equivalent temperature cycles in synchrony. A 25 percent increase in earth greening in the recent decade of increased carbon emissions would suggest carbon as methane is not detrimental to our climate.
Who has measured our methane gaseous bank and is it increasing, decreasing or stable? It would appear it is a gaseous fertiliser bank free for farmers of the world to use along with nitrogen, hydrogen and oxygen the backbone of carbohydrates and protein for plant animal and human use. Logically as more carbon is produced, more food, pasture and meat can be produced to support 8.2 billion people and growing. Is that counter intuitive to Doomer doctrine?