Anthropogenic Decline in Natural Gas

Guest Post by Willis Eschenbach

Well, Nature Geoscience is on a roll. Their latest “scientific study” makes an old claim in a new way. After ascribing the temperature changes in Lake Tanganyika to human actions, in a new paper they are now ascribing the changes in the climate 12,000 years ago to the actions of humans in changing the methane levels …

Figure 1. The real reason for the ending of the Ice Age

No, that’s not from the Nature Geoscience article. We’ll get to that, but first , a short cruise through the historical methane data.

As usual, the NOAA Paleoclimatology site has the goods.  The data shows an interesting thing. This is that, like CO2, the amount of methane in the air is a function of the temperature. Figure 2 shows the relationship.

Figure 2. Relationship between temperature and methane, Vostok ice core data, last half million years. Image Source

As you can see, temperature and methane are tightly coupled. The relationship is that when temperature raises by 1°C, the methane concentration in the atmosphere goes up by about 24 parts per billion by volume (ppbv). The reasons for this are not entirely clear, but the methane mostly comes from natural fermentation in wetlands. And as anyone knows who has made the prison liquor called “swipe” from potato peelings in a mason jar, fermentation increases with temperature … or that’s what I’ve read, at any rate, I wouldn’t know about that myself …

So what did the Nature Geosciences article say about methane? It is entitled “Methane emissions from extinct megafauna”, by Smith et al. (hereinafter S2010). You have to pay them $18 to have the privilege of reading it. My advice is, don’t waste your money.

Their claim is that the drop in temperature about 12,000 years ago known as the “Younger Dryas” is due in part to the loss of methane from the eeeevil humans killing off the large animals of North America. This reduced the amount of methane from the … well, let me call it “spontaneous release of large parcels of intestinal gases” of the extinct “megafauna”, the ground sloths and mastodons and wooly mammoths and the like. Here’s their graphic of the event:

Figure 3. Graphic from the S2010 paper.

Note how they clearly show that humans come to North America, and very quickly the methane concentration dropped. (As an aside, don’t they know that Jim Hansen said that American temperatures are meaningless because America is only a few percent of the planet’s surface area? Also, note that they claim that species loss could be responsible for “12.5 to 100%” of the methane decline. Now that’s what I call a robust confidence interval, a variation of eight to one. But I digress …)

I showed above that methane concentration is driven by temperature changes, and has been for a half-billion years. However, they say that this particular event is unique. Why? Not because suddenly the temperature/methane relationship broke down. After all, the methane concentration during the Younger Dryas event is totally predictable from the temperature, just like the during the rest of the half billion years.

Figure 4. Methane levels in the Younger Dryas, featuring the usual flatulent suspects. Methane data from NOAA, showing Greenland ice core methane levels. Note that the temperature changes correlate very well with the changes in methane. Temperature changes inferred from d18O levels. Difference in dating from Figure 3 is because this chart shows years BC.

So why blame megafaunal methane for the drop? Well, because the methane levels drop so fast. I kid you not. In their words:

Moreover, the changes in methane concentration at this time seem to be unique. A comparison with the five largest drops over the past 500,000 years shows that the Younger Dryas transition was characterized by a methane decrease that was two to four times more rapid than any other time interval (Supplementary Table  T3, P  < 0.01 to P  < 0.001), which suggests that novel mechanisms may be  responsible.

Now, they ignore the fact that among the historical drops in methane levels, one has to be the largest, so finding the largest one means nothing. And they ignore the well-known and aptly named “Noah Effect”, whereby the largest of a group of natural phenomena is often much, much larger than the second largest of the same phenomena. These together are more than enough to explain the rapidity of the methane drop at the start of the Younger Dryas.

Instead, following the Rahm Emanuael dictum, “Never let a serious crisis go to waste”, they have blamed the precipitous drop in methane at the start of the Younger Dryas on human meddling with the biosphere. We killed the mammoths, their argument goes, which stopped them from cutting loose with … large spontaneous emissions of biomethane … and that made the atmospheric methane levels plunge off of the proverbial cliff. QED.

Now, I suppose that their claim is theoretically possible, and they do a lot of plain and fancy tap dancing to show that it is so, but I’m just a cowboy, so that gives me the right to ask the dumb questions:

1. If missing mammoth methane was the cause of the extremely rapid drop in methane … then what was the cause of the following extremely rapid rise in methane? I mean, the megafauna didn’t suddenly become un-extinct and start passing gas again. So why did the methane suddenly rise again?

For this one, I have no answer other than the obvious one … both the drop and the rise in methane were caused by a drop and rise in temperature. The authors of S2010, however, show no interest in this important question … if the cause of the rapid drop in methane during the Younger Dryas is not temperature but a deficiency in ground sloth gas, then what is the cause of the rapid rise in methane?

2. Is the change in methane forcing significant enough to create such a large temperature change? The S2010 paper says:

Ice-core records from Greenland suggest that the methane concentration change associated with a 1  °C temperature shift ranges from 10 to 30  ppbv, with a long-term mean of about 20  ppbv (ref. 13).Thus, empirically, the 185 to 245  ppbv methane drop observed at the Younger Dryas stadial is associated with a temperature shift of 9 to 12  °C. The attribution and magnitude of the Younger Dryas temperature shift, however, remain unclear. Nevertheless, our calculations suggest that decreased methane emissions caused by the extinction of the New World megafauna could have played a role in the Younger Dryas cooling  event.

Well, yeah … but the IPCC says that methane forcing varies linearly with  concentration. It also says that a change in methane of 100 parts per billion by volume (ppbv) leads to a change in forcing of 0.05 Watts per square metre (W/m2). Given the methane change in the Younger Dryas of ~200 ppbv, this would result in a methane forcing change of a tenth of a watt per square metre (0.1 W/m2).

Now, the IPCC says that a forcing change of 3.7 W/m2 (from a doubling of CO2) would lead to a temperature change of 3°C. I think this is way too large, but we’ll let that be and use their figure. This means that the Younger Dryas change in methane forcing of 0.1 W/m2 would lead to a temperature change of 0.08°C …

Eight hundredths of a degree? These people are hyperventilating over eight hundredths of a degree? I spent eighteen buck to read their !@#$%^ paper for eight hundredths of a degree? That trivial change in forcing is supposed to have “played a role in the Younger Dryas cooling  event”?I weep for the death of science.

(And since you ask, yes, I do marvel that I was able to get through this without once saying the dreaded phrase “mammoth far…” … hey, wait a minute, whoa, that was close, you almost got me there …)

[UPDATE] There’s another oddity I just noticed about the paper. They use the following formula to calculate the methane emissions:

(4) DMIe = BMe^0.75 *[ (0.0119*NEma^2 + 0.1938)/NEma] where BMe = body mass in kg, and NEma = estimated dietary net energy concentration of diet in MJ/kg

Now, one of the rules of math that was endlessly drummed into our heads by my high schoo chemistry teacher (thank you, Mrs. Henniger) was that the units follow the same rules as the numbers. For example, here’s the formula relating distance (S), acceleration (A) and time (T)

S = 1/2 A * T^2

With S in metres, A in metres/second^2 and T in seconds, this is

metres = metres/second^2 * second^2

or

metres = metres

So far, so good. Now let’s look at the units in their formula:

kg = kg^0.75 * [ (MJ/kg)^2 / (MJ/kg) + 1/(MJ/kg) ]

Simplifying, we get

kg = kg^0.75 * [ (MJ/kg) + 1/(MJ/kg) ]

kg = kg^-0.25 *MJ + kg^1.75 /MJ

Well, that’s certainly a fascinating combination of units, but it is definitely not kilograms as advertised.

So I looked to see where they got the formula … and as I should have guessed, it is from the IPCC

Mrs. Henniger would not approve, she used to wield her red pencil like Thor’s own hammer on this kind of nonsense.

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Dennis Wingo

Willis
Small comment, it is Younger Dryas in the text, not “Little” as was written.
Otherwise great article!

PJB

Science may be dead, but the Agenda lives on…

These scientists are absolutely mad!
How many grant money do they recieve for sh*t (methane!) like this?
Now, I propose this study for one of 2010 Ignobels: http://improbable.com/ig/
Ecotretas

stumpy

Another point worth raising, it the mamoths would eat plants for food, this would then break down in the digestive system and result in the release of methane, but the food they ate would have been a sink of co2. Methane is more potent then co2, but doesnt it change to co2 in the atmosphere within a short period of time from release? What they are talking about is the “contemporary carbon cycle”. No one was digging up historic co2 / methane locked deep underground and putting it in the atmosphere, what the mamoths are releasing comes from their food and their food absorbs it from the atmosphere. Its as stupid as the cow farts cause warming myth Greenpeace constantly talk up so we all go vege for them.

Mark Nutley

Pure Flatulance 🙂

Tom in Florida

That may be the best $18 I never spent. Thanks for the savings.

stan stendera

Echenbach’s Hawk floats on a cloud of Mastodon far…wait methane!

Policyguy

The Clovis were also part of that extinction event. I doubt they turned on themselves while they had so much megafauna to abuse.
And Nature printed this? Yet another peer reviewed piece that will now be cited over and over as accepted truth. Gag.

vboring

The methane emissions could have started to rise again because of the increase in populations of domesticated sheep, pigs, and cows.
I don’t know exactly when that happened, but it should be around the right sort of time frame.

Al Gore's Holy Hologram

I didn’t even need to read most of this. The number of humans and wooly mammoth in North America and Siberia was miniscule. Not even imaginably close enough to affect global methane levels and temperature.

Willis Eschenbach

Dennis Wingo says:
May 27, 2010 at 1:22 pm

Willis
Small comment, it is Younger Dryas in the text, not “Little” as was written.
Otherwise great article!

Thanks, fixed.
w.

Tommy

I tried to find more info about “swipe” but it makes a poor search term. I did find a funny article about a related substance: MAKE YOUR OWN PRUNO AND MAY GOD HAVE MERCY ON YOUR SOUL.
So, if extinction of megafauna results in cooling, then why aren’t the Nature Geosciences guys recommending extermination of all giraffs and elephants to save the world from CAGW?

Patrik

So.. To save us from catastrophic warming, all we have to do is…
Kill all elephants?
😉

D.S. Overcast

So I always wonder about the methane causing effects of Global Warming that the AGW proponents spout forth and think if what they say is true, then did we stop a Global Catastrophy by nearly wiping out the Buffaloe when we colonized America? If so…is that a good thing? 🙂

Phyllograptus

Just a question. It sure looks like on Figure 2 that the rise in Methane concentrations pre-dates the temperature rise, which would imply cause-effect of methane concentration increase leads to temperature increase, rather than as discussed in the post of temperature increases causing methane concentration increases. However I admit without vertical lines it is difficult to accurately judge which rise precedes the other in Figure 2

Flask

A peer-reviewed paper?
Very robust flatulence.

Johnny D

Perhaps you should submit your thoughts as a comment to Nature Geoscience, where it will be printed, if it truly does have merit, along with the authors’ response. (I won’t be holding my breath, however.)
Clearly, the authors, editors, and peer reviewers, likely experts in paleoclimatology, thought it was a worthwhile analysis. I’m going to trust their judgment more than I trust some blogger’s.

MattN

It is utterly amazing the crap they publish. This article isn’t worth lining my bird’s cage…

kwik

It could also be that the Clovis people changed from eating roots to eating Mammoths.
And thereby the clovis people’s farting frequence and amplitude dropped dramatically?
Yes? Its possible? Within, say, 5 to 95% confidense interval? Robustly?
But seriously, what do real Scientists say about the reason for the Younger Dryas?
The Cometh was a coming?

P.G. Sharrow

Just one more proof that a Phd has been wasted on people without the intelligence of good sense. I know that the religion of human caused climate change needs all the arguments they can raise, but stupid is as stupid does. In nearly 60 years this is not the first time that I have seen a lame conclusion drawn from the facts.

Enneagram

No more doubts!, this paper conclusively demostrates that farting goes after warming.

Dave Wendt

I’ve always had some problems with the notion that over hunting by our wily ancestors was responsible for the extinction of the Mammoths. I’ve always wanted to see an experiment done, where we gather about a dozen of the proponents of this theory together, arm them with stone tipped spears, and lock them in a pen with a bull elephant wrapped in a coat of shag carpet, just to see which species would prove to be a more likely candidate for extinction.

John in NZ

Good article Willis.
Small typo. “about 24 parts per billion by volume (ppmv).” should that be be (ppbv)

Dave Andrews

AL Gores H H
“I didn’t even need to read most of this. The number of humans and wooly mammoth in North America and Siberia was miniscule. Not even imaginably close enough to affect global methane levels and temperature.”
Presumably that’s why they said the loss of these species could be responsible for 12.5 to 100% of the methane decline (pretty wide margin) 🙂

Milwaukee Bob

Ok, all sing along:
Home, home on the range. Where the sloths and mastodons roam.
Where seldom is heard……
….. Hmm, what is that smell?
Oh, yes. The paper. Forget the song, they’re long gone anyhow.
Well, we are gathered here around the camp fire…..
What is that smell?
As I was saying, ….. around the camp fire to peer-review this “scientific study” that makes an old claim in…….
What IS THAT smell!?!
Jimmy! You been in the beans again? No?
Then what is that smell?
…..
PHEW! It’s coming from this paper!! Quick! Throw it in the fire!

Ray

Strange how organic material decomposition is also directly related to temperature… when the temperature is high things decompose and produce methane (except for rocks!!!), and when the temperature drops the decomposition slows down and even stops at a certain temperature. Strange how the biosphere grown also reacts favorably with temperature increases… the more organics, the bigger the methane reservoir.

Mike

I found this, it gives a little more detail:
http://www.physorg.com/news193847219.html (There is a typo where 2-40 should be 2-4, I think.)
Willis asked: “If missing mammoth methane was the cause of the extremely rapid drop in methane … then what was the cause of the following extremely rapid rise in methane? I mean, the megafauna didn’t suddenly become un-extinct and start passing gas again. So why did the methane suddenly rise again?”
I’ll make a guess. Smaller animals would increase in population to fill the void. They fart too! For example, maybe buffalo became prevalent in the next view hundred years. I bet they can cut lose! One test of this is to see if methane levels declined after Europeans killed off most of the buffalo.
There is another line of research that suggests comet activity caused the YD and the decline of megafauna. See:
http://www.sciencemag.org/cgi/content/abstract/323/5910/94
See also a response here:
http://www.realclimate.org/index.php/archives/2009/01/the-younger-dryas-comet-impact-hypothesis-gem-of-an-idea-or-fools-gold/
So, it seems there is no consensus on the cause of the YD event.
http://en.wikipedia.org/wiki/Younger_Dryas#Causes_of_the_Younger_Dryas
Probably more than one factor was involved and these may have had feedbacks with effected each other.

Tilo Reber

So we can assume that the new North American immigrants had no problems with flatulence themselves.
In any case it’s obvious to me that the only way to rescue mother earth is with the complete extinction of all mankind. The number of people in North America at that time was absolutely tiny. So if mankind is so virulent to the planet, the only solution is to get rid of mankind. Al Gore and his friends will be the exception. Someone has to stay behind, fly around, and make sure that no one cheats when we all take the Jim Jones elixer.

Enneagram

Los que trabajan en espacios cerrados, por lo general los modelos jugando en sus computadoras, son propensos a padecer enfermedades pulmonares causadas por la inhalación de una alta concentración de H2S CH4 ans. Su ingesta continuada provoca “delirio climatologicum extremis”

Bruce Cobb

“Eight hundredths of a degree? These people are hyperventilating over eight hundredths of a degree?”
Yes, but you’re forgetting that this tiny negative forcing was caused by eeevil humans, thus upsetting Gaia’s delicate balance, resulting in self-reinforcing negative feedbacks, a tipping point and a death spiral of climate. Since we weren’t driving Hummers back then, there was nothing to counter-balance that negative feedback.
Ack. I need to stop channeling Alarmists. Not good for the psyche.

AnonyMoose

vboring says:
May 27, 2010 at 1:38 pm
The methane emissions could have started to rise again because of the increase in populations of domesticated sheep, pigs, and cows.
I don’t know exactly when that happened, but it should be around the right sort of time frame.

Searching for your “domesticated sheep” phrase: Sheep and goats, cattle and pigs: 9000-7000 BC
So you missed it by 3,000 years. Dogs, however, were 12,000 years ago according to that source. But the domestication of dogs by hunters should have only made hunting better, thus the killing-leading-to-cooling should have gotten worse.

H.R.

Megafauna and methane?
Not all of the bubbles that whales blow are from their lungs ;o)
I can develop a good proxy for whale gas by studying kids in swimming pools. Where’s my grant money?

OT
Volcanic plumes generate lightning from the electrification of plume particles.
Electrification of volcanic plumes provides a spectacular source of lightning.
……….findings demonstrate that charge exists well within a volcanic plume, the origin of which is not readily attributable either to the eruption directly or subsequent fair weather charging. ….. Charged particles can cause aircraft radio interference and, if introduced into aircraft cabins, charged ash may present an electrostatic hazard to occupants or aircraft systems.

http://iopscience.iop.org/1748-9326/5/2/024004/fulltext#SECTIONREF

Paul Linsay

Must have been Blazing Mammoths that caused the high temperatures.

Leon Brozyna

Another study full of … hubris.
Mankind’s impact on the climate may be no greater than the impact of fleas jumping on an elephant’s backside as it jogs through the savannah. The difference is that the fleas don’t imagine they’re having an impact on the course of the elephant’s movements.

Steve Fitzpatrick

Willis,
A very good analysis; you go right to mindless stupidity of it all. Another in the long line of “mankind is always bad” climate science papers. How the heck did you bring yourself to spend the $18 on such nonsense?
Since you are clearly spending some time on paleo climate data, have you looked at the divergence of ice core temperature trend and ice core CO2 starting about 8 Ky ago? Looks like rising CO2 (which was significant) is the opposite of what would be expected from the downward trend in temperature over the same period. Watts with that?

Casper

I think the methane comes mainly from the oceans, to be more precisely from the methane clathrates. At first, it becomes hotter and then methane is released into the atmosphere. Just look on the first diagram. This is the Henry’s law!

Reed Coray

I want to know who paid for this “stinking study.”

Willis Eschenbach

Phyllograptus says:
May 27, 2010 at 1:46 pm

Just a question. It sure looks like on Figure 2 that the rise in Methane concentrations pre-dates the temperature rise, which would imply cause-effect of methane concentration increase leads to temperature increase, rather than as discussed in the post of temperature increases causing methane concentration increases. However I admit without vertical lines it is difficult to accurately judge which rise precedes the other in Figure 2

Exact dating of the ice core data is problematic, so we can’t conclude much from those kinds of very small differences.

Willis shouts: “I spent eighteen buck to read their !@#$%^ paper for eight hundredths of a degree?”
Your loss is our gain, Willis! Many thanks for this highly entertaining and entirely reasonable post. :o)

Tom Bakewell

Gosh, I thought this was a serious submission to the Journal of Irreproducable Results. It sure reads like a serious submission to the JIR (RIP) .Or maybe that should read ‘submission to the serious JIR’.

Larry Fields

Willis, great anal-ysis! Sorry, I can’t resist the temptation to make a bad pun. The Flying CO2 Monster made me do it!

Willis Eschenbach

Johnny D says:
May 27, 2010 at 1:52 pm

Perhaps you should submit your thoughts as a comment to Nature Geoscience, where it will be printed, if it truly does have merit, along with the authors’ response. (I won’t be holding my breath, however.)
Clearly, the authors, editors, and peer reviewers, likely experts in paleoclimatology, thought it was a worthwhile analysis. I’m going to trust their judgment more than I trust some blogger’s

Trust climate scientists? That’s charmingly naive, Johnny. Me, I don’t trust anyone … including myself. If you think I’m wrong, I invite you to show me where.
Finally, if you think “authors, editors, and peer reviewers” are the judge of scientific validity, you don’t understand the scientific method. A large percentage of papers printed in peer-reviewed journals, which have been approved by “authors, editors, and peer reviewers”, are shown to be false within a few years of publication.

Joe Crawford

I can’t imagine the drop in “Methane emissions from extinct megafauna” 12,000 BC were any greater than that lost from the 25 to 30 million bison (at approx. 2,000lb each) that were killed off in North America between the 1700-1900 AD. Shouldn’t we see a climate change comparable to the Younger Dryers starting around 1750 or so?

Willis Eschenbach

John in NZ says:
May 27, 2010 at 2:10 pm

Good article Willis.
Small typo. “about 24 parts per billion by volume (ppmv).” should that be be (ppbv)

Thanks, John, fixed.

Michael

What is the life span of those animals 25 years or so? They all would have died in a relatively short period of time any way without any help from man, thus making what happened 12,000 years ago happen without mans help and would still have contributed to whatever it is they are talking about. So what is their point?
In other news;
Iceland President Warns That “Significant Eruption At Katla Volcano Is Close
http://www.zerohedge.com/article/iceland-president-warns-significant-eruption-katla-volcano-close

how do they even get crap like that published? i mean, it’s utterly ridiculous, in its entirety.
science has been so hopelessly politicized.

Willis Eschenbach

Enneagram says:
May 27, 2010 at 2:26 pm

Los que trabajan en espacios cerrados, por lo general los modelos jugando en sus computadoras, son propensos a padecer enfermedades pulmonares causadas por la inhalación de una alta concentración de H2S CH4 ans. Su ingesta continuada provoca “delirio climatologicum extremis”

Y eso es una enfermedad muy común en estos dias …
w.

Dave Wendt

The conventional number for methane concentration at present is about 1800 ppbv. About a decade ago Evans and Puckrin did a study to which used spectral analysis of downwelling longwave radiation to quantify the contribution of the various GHGs to the greenhouse effect.
http://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
They used a model to predict the preindustrial atmosphere’s response and claimed about a 30% increase in present time based on their measurements, although the data they listed didn’t really seem to support that very well. The point is that neither their model or their measurements indicated that methane contributed more than 1.3 Wm2 to total DLR which ranged from 150Wm2 in winter to 270Wm2 in summer at their Canadian location. That would suggest that if methane disappeared from the atmosphere entirely the most that could be expected would be about a 1Wm2 decrease in the greenhouse effect, which wouldn’t seem sufficient to generate an event like the Younger-Dryas

Willis Eschenbach

Steve Fitzpatrick says:
May 27, 2010 at 2:48 pm

Willis,
A very good analysis; you go right to mindless stupidity of it all. Another in the long line of “mankind is always bad” climate science papers. How the heck did you bring yourself to spend the $18 on such nonsense?
Since you are clearly spending some time on paleo climate data, have you looked at the divergence of ice core temperature trend and ice core CO2 starting about 8 Ky ago? Looks like rising CO2 (which was significant) is the opposite of what would be expected from the downward trend in temperature over the same period. Watts with that?

I’ve noticed that in my past investigations, no idea why it exists. I’ll look at it again.