Inconvenient: worms, clams, release as much greenhouse gas as 20,000 dairy cows

From CARDIFF UNIVERSITY and the “inconvenient critters” department.

Baltic clams and worms release as much greenhouse gas as 20,000 dairy cows

New study shows that oceans with worms and clams enhance the release of methane into the atmosphere up to eight times more than oceans without them

Scientists have shown that ocean clams and worms are releasing a significant amount of potentially harmful greenhouse gas into the atmosphere.

The team, from Cardiff University and Stockholm University, have shown that the ocean critters are producing large amounts of the strongest greenhouse gases – methane and nitrous oxides – from the bacteria in their guts.

Methane gas is making its way into the water and then finally out into the atmosphere, contributing to global warming – methane has 28 times greater warming potential than carbon dioxide.

A detailed analysis showed that around 10 per cent of total methane emissions from the Baltic Sea may be due to clams and worms.

The researchers estimate that this is equivalent to as much methane given off as 20,000 dairy cows. This is as much as 10 per cent of the entire Welsh dairy cow population and 1 per cent of the entire UK dairy cow population.

The findings, which have been published in the journal Scientific Reports, point to a so far neglected source of greenhouse gases in the sea and could have a profound impact on decision makers.

It has been suggested that farming oysters, mussels and clams could be an effective solution against human pressures on the environment, such as eutrophication caused by the run-off of fertilisers into our waters.

The authors warn that stakeholders should consider these potential impacts before deciding whether to promote shellfish farming to large areas of the ocean.

Co-author of the study Dr Ernest Chi Fru, from Cardiff University’s School of Earth and Ocean Sciences, said:

“What is puzzling is that the Baltic Sea makes up only about 0.1% of Earth’s oceans, implying that globally, apparently harmless bivalve animals at the bottom of the world’s oceans may in fact be contributing ridiculous amounts of greenhouse gases to the atmosphere that is unaccounted for.”

Lead author of the study Dr Stefano Bonaglia, from Stockholm University, said: “It sounds funny but small animals in the seafloor may act like cows in a stable, both groups being important contributors of methane due to the bacteria in their gut.

“These small yet very abundant animals may play an important, but so far neglected, role in regulating the emissions of greenhouse gases in the sea.”

To arrive at their results the team analysed trace gas, isotopes and molecules from the worms and clams, known as polychaetes and bivalves respectively, taken from ocean sediments in the Baltic Sea.

The team analysed both the direct and indirect contribution that these groups were having on methane and nitrous oxide production in the sea. The results showed that sediments containing clams and worms increased methane production by a factor of eight compared to completely bare sediments.

###

0 0 votes
Article Rating
118 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
SMC
October 13, 2017 1:04 pm

Where do I get a cow with a flame thrower butt? :))
The picture is hilarious.

rocketscientist
Reply to  SMC
October 13, 2017 1:05 pm

I was chuckling as well.

Bob Hoye
Reply to  SMC
October 13, 2017 3:43 pm

If you think the picture is hilarious, try it in real time.
Twenty years old, heading up a survey party for the Dept of Highways. One evening one of the “kids” in the crew talked about it. I was doubtful.
Outside the bunkhouse and into the failing light of dusk.
It works!!!!!!
Best to leave the underwear on–flashback.
The most hysterical and falling down laughter in my lifetime.

JustAnOldGuy
Reply to  Bob Hoye
October 13, 2017 5:09 pm

It’s all fun and games until someone loses an eye…..or somethin’. And think about the trade-off, methane for CO2 and water vapor from the combustion.

Greg
Reply to  Bob Hoye
October 14, 2017 10:59 am

sure it works , great party trick but make sure you have a strong pair jeans with no holes. A blow-back will explode your bowel and likely kill you. Then you look less funny.
BTW really rank farts don’t burn.

Baltic clams and worms release as much greenhouse gas as 20,000 dairy cows

So WTF? There are feeding lots which have more than 20,000 beasts, that is insignificant.

drednicolson
Reply to  Bob Hoye
October 14, 2017 12:52 pm

Use the bathtub trick to catch your payload in a bottle before igniting. Same results, no risk of literal explosive diarrhea. :]

Philip of Taos
Reply to  SMC
October 13, 2017 4:12 pm

Sure it sounds fun but the insurance is really expensive.

Greg
Reply to  Philip of Taos
October 14, 2017 11:00 am

Fine gauge, metal gauze, spark-arresting underpants recommended.

Reply to  SMC
October 15, 2017 7:28 pm

except of course that cows belch methane. 🙂

rocketscientist
October 13, 2017 1:05 pm

But the worms and clams are much harder to milk.

SMC
Reply to  rocketscientist
October 13, 2017 1:32 pm

I can understand trying to milk worms… They kinda, sort’a, maybe look like teets (depends on how drunk and cross eyed you are). But, do clams even have teets? 🙂

Gabro
Reply to  SMC
October 13, 2017 2:01 pm

But clam juice and tomato juice in beer are like mother’s milk to me.

Paul Penrose
Reply to  SMC
October 13, 2017 2:08 pm

Gabro,
Doesn’t sound too appetizing to me. Now a good stout aged in a bourbon barrel…now that’s a different story – yum, yum.

Paul r
Reply to  SMC
October 13, 2017 8:58 pm

We need a clam tax. There problem solved.

AndyG55
Reply to  rocketscientist
October 13, 2017 5:55 pm

“But the worms and clams are much harder to milk.”
Mate, those climate scientist and their fellow left wing politicians….. can milk ANYTHING !!

rocketscientist
October 13, 2017 1:11 pm

Termites have them beat by a long shot.
Scientists estimate that, worldwide, termites may release over 150 million tons of methane gas into the atmosphere annually.
And termites are 5 times the biomass of all humans.

Nigel S
Reply to  rocketscientist
October 13, 2017 1:32 pm

Thanks, that was what I wanted to say too, hard working creatures, an example to us all.

Gary Pearse
Reply to  Nigel S
October 13, 2017 2:54 pm

Old saying, having personally lived through the end of the era of the dray horse and steam locomotive, “A farting horse never tires.” This was because a working horse was fed oats. Otherwise, they ate only hay and grass. In those days, they noted that on Mondays, a horses urine turned brown after a feed of oats. It was rich feed until he got into his workday. I’ll bet the methane was thick in those days.

rocketscientist
Reply to  Nigel S
October 13, 2017 3:18 pm

Flies too.

johchi7
Reply to  rocketscientist
October 14, 2017 11:57 am

http://www.bioone.org/doi/10.3958/059.042.0201
.” CO2 emissions from as few as 50 termites ranged from 442.6 to 660.9 ppm, a net increase of 33% between time zero and 60-minute sampling events. Fifty termites emitted similar increases in CH4, from 2.6 to 5.7 ppm during 60 minutes, a 55% net increase.”
http://www.thehexapodacollection.com/about/insects-amazing-facts/
“It is estimated there are 30 million different species of insects, making up almost 90% of all living things on the planet.
· Insects would outweigh all other animals by weight.
· The world’s Termites outweigh the world’s Humans 10 to 1.
· About one-third of all insect species are carnivorous and most hunt for their food rather than eating decaying meat or dung.
· Insects have been present for about 350 million years – Humans for only 130,000 years.
· There are more insects in one square mile of rural land than there are human beings on the entire earth.”
Over the past I have commented that the exponential increase of Bio-Mass since the Last Ice Age is the main cause of the increased Carbon Dioxide in our environment. With increased Carbon Dioxide it creates a greener Earth of exponentially increased Flora that Exponentially feeds more Fauna that produce more CO2 that creates more Flora. Humans are just a tiny percentage of that exponential increase as members of Fauna and even our uses of Fossil Fuels GHG’s are minute compared to the rest of the Bio-Mass.
Even if humans were to stop all uses of Fossil Fuels the rest of the environment would exponentially increase GHG’s and therefore the alarmist want to hold humans as demons intent on destroying the planet for our contributions…and yet our Fossil Fuels contributions have increased Bio-Mass health to the environment. The insignificant “Warming” is their creation to demonize Capitalism, while they are promoting Capitalism by the creation of all these “Green Energy” and “Renewable Energy” sources that have increased the amount of Carbon Dioxide in the environment for decades in their manufacturing of them from the Fossil Fuels they demonize, for the ideology that they will reduce Carbon Dioxide in the future by replacing common reliable Energy Sources that use Fossil Fuels directly for the energy needs of the here and now. Progressivism is a Mental Defect of Today’s Liberal Mind. How can Alarmist care about how much Carbon Dioxide has increased the Global Temperature since the Industrial Age, while pumping more Carbon Dioxide into the environment NOW, to address the future increase of GHG’s and Climate Changes created by Global Warming that is – to them – going to happen too soon?

eyesonu
October 13, 2017 1:28 pm

Worms and clams seem to make a warm and happy union and not much concerned about global warming.
Now .. about all those wildebeest in Africa. Kill the wildebeest to save the African prairie and thus the earth! And besides that they are mean and aggressive bullies.

SMC
Reply to  eyesonu
October 13, 2017 1:34 pm

But if you kill the wildebeast then the crocodiles will starve. Then we’ll have to protect the endangered crocodile. Maybe we should put them on the endangered species list proactively.

drednicolson
Reply to  SMC
October 14, 2017 1:16 pm

Nah, they’ll just eat people instead. One Egyptian saltwater croc in particular, nicknamed “Gustav”, is reputed to have killed and eaten over 200 human victims.

Reply to  eyesonu
October 13, 2017 1:58 pm

The best way is to do what was done in Yellowstone, reintroduce the predators.

October 13, 2017 1:50 pm

If it was CO2 that these worms and bivalves released, that wouldn’t increase the GHG effect at all, as all CO2 released by all living creatures was captured by photosynthesis out of the atmosphere a few days to a few decades before.
In this case, CO2 was captured by plankton out of the oceans mostly near the surface and as the ocean surface is in close contact with the atmosphere (exchange rate less than a year), mostly out of the atmosphere.
There is some increase in GHG effect, as methane is an about 20 times more potent GHG carbon per carbon. On the other side, CH4 is readily broken down to CO2 in the upper troposphere by OH radicals from the splitting of water molecules by UV light. Half life time about 10 years.
Thus all together, the natural breakdown of food and feed by microbes, molds, insects, animals,…) is of little influence on the GHG effect and not the cause of the current increase of CH4 or CO2 in the atmosphere as, according to the oxygen balance, the total biosphere (land + water plants and what feed on them), is more CO2 sink than source:
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf

Samuel C Cogar
Reply to  Ferdinand Engelbeen
October 14, 2017 9:10 am

So claimith: Ferdinand Engelbeen – October 13, 2017 at 1:50 pm

There is some increase in GHG effect, as methane is an about 20 times more potent GHG carbon per carbon.

So, ….. claiming 20 times more potent potentially above, …… whereas claiming 28 times more potentially potent below.
Excerpted from article:

Methane gas is making its way into the water and then finally out into the atmosphere, contributing to global warming – methane has 28 times greater warming potential than carbon dioxide.

Would someone please make up my mind for me so that I can be as smart as they are.
If CH4 (methane) has 20/28 times greater atmospheric warming potential than CO2 (carbon dioxide), ….. then how many times greater than atmospheric CO2 is the atmospheric warming potential of water (H2O) vapor?
I shur hope that was not too tuff a question to be asking, …… but I will be greatly surprised iffen anyone admits to knowing the answer.
And the next obvious question is, …… if the measured temperature of the near-surface atmosphere in the temperate latitude is at 75 degrees F, which of these three (3) gas types contain the most thermal (heat) energy, ….
CH4 (methane) ——- @ 1.745 ppm
CO2 (carbon dioxide) @ 400 ppm
H2O (water vapor) — @ 27,000 ppm
Ya’ll get three (3) guesses and your 1st two guesses don’t count.

Greg
Reply to  Samuel C Cogar
October 14, 2017 11:08 am

AR4 said 22x IIRC, but this is all matter of knowing how long each species remains in the atmosphere and CO2 alone I’ve heard values ranging from 50 to several 1000 years.
Like most of this crap you just make it up and chose a figure which best suits you argument.

Carbon BIgfoot
Reply to  Samuel C Cogar
October 14, 2017 2:06 pm

Here is the best presentation I’ve experienced. You’ll be smarter than anything.

Samuel C Cogar
Reply to  Samuel C Cogar
October 15, 2017 3:49 am

Greg – October 14, 2017 at 11:08 am

but this is all matter of knowing how long each species remains in the atmosphere and CO2 alone I’ve heard values ranging from 50 to several 1000 years.

Shur nuff, Greg, …… shur nuff.
And I’m here to tell you, …….. so that you can also claim you heard, ……… that those AGW CO2 molecules bring released into the atmosphere …… are EXACLY similar to ……. the raindrops that fall onto the surface water of Lake Tahoe, Nevada, …… with a few of those raindrops flowing out of Lake Tahoe and down the Truckee River in less than 8 hours after falling on the surface waters …… whereas some of the other raindrops will remain in Lake Tahoe for several 1,000 years.

Reply to  Samuel C Cogar
October 16, 2017 2:30 am

Samuel,
It doesn’t matter much if the GHG potential of CH4 is 20 or 22 or 28 times CO2, it does only matter if the levels change. In this case emitting CH4 molecule per molecule CO2 taken away out of the atmosphere has a small effect.
The same for water vapor: even if water is the most important GHG, as long as its content in the atmosphere doesn’t change, it is not important.
Next, thermal energy of the GHGs is of little interest either, only how much energy is retained by the different GHGs and put into knietic energy of all surrounding air molecules and how much is reflected back to the earth surface is important.

Reply to  Samuel C Cogar
October 16, 2017 2:48 am

Carbon Bigfoot,
Sorry but that story from Dr. Segalstad is completely outdated and refuted on so many points, that I don’t even want -again- to start any rebuttal here. Just hear what he said about ice core CO2 in the Siple Dome, as based on the writings of Dr. Jaworowski. The researchers didn’t arbitrarely shift the data to match the Mauna Loa data, Jaworowski and Segalstad simply were wrong as they didn’t take into account the difference in average age between ice and enclosed air in ice at the same depth: they looked at the column of the ice age, not the gas age…
See further:
http://www.ferdinand-engelbeen.be/klimaat/jaworowski.html

Samuel C Cogar
Reply to  Samuel C Cogar
October 16, 2017 4:32 am

Ferdinand Engelbeen October 16, 2017 at 2:30 am

Samuel,
It doesn’t matter much if the GHG potential of CH4 is 20 or 22 or 28 times CO2, it does only matter if the levels change. In this case emitting CH4 molecule per molecule CO2 taken away out of the atmosphere has a small effect.
The same for water vapor: even if water is the most important GHG, as long as its content in the atmosphere doesn’t change, it is not important.

Ferdinand, …… your “weazelwording” talent is utterly amazing.
Anyone that can speak/write as much as you can without actually stating anything of factual OR scientific importance …… has no compelling need of being “science literate” in any discipline in order to achieve “status & position” in today’s 21st Century Academia wherein “pal approval” is one’s Mark of Excellence.
You are ABSOLUTELY correct, ….. Ferdinand, …… iffen the atmospheric content/quantity of carbon dioxide (CO2) and water (H2O) vapor NEVER CHANGES from day-to-day, …. month-to-month …… or century-to-century, …….. then the “fear mongering” claims of catastrophic AGW would never have been thunked up and touted as science “fact”.
But all designated GHG (radiative) atmospheric gasses are “quantity” variable gasses …… with their atmospheric quantities varying from day-to-day, …. month-to-month, …… year-to-year …… and/or century-to-century, …….. with the atmospheric water (H2O) vapor having THE GREATEST change in day-to-day, week-to-week, …. or month-to-month ppm quantities (15,000 to 40,000+ ppm).
Ferdinand, there is no way in ell that that the AGW effect that is attributed to carbon dioxide (CO2) is even remotely comparable to the AGW effect that can be attributed to water (H2O) vapor.

Barbara
October 13, 2017 1:57 pm

ON Nature, Winter 2008/2009
“The Mussel Crisis”, 4 pages with photos
Re: North American native Mussels.
“Shockingly, more than half of North America’s freshwater mussels are in danger of going extinct.”
The Great Lakes have suffered a great loss of native freshwater clams.
There is much more up-dated information on this subject online.
In the past, freshwater clam shells were used to make pearl buttons which were stamped-out circles from clam shells.
http://ontarionature.org/protect/PDFs/Mussels_W08.pdf

Juice
October 13, 2017 2:02 pm

Are they saying that the entire methane output by clams and worms in the entire Baltic Sea is as much as 20,000 dairy cows? Um well, ok. Not sure why they made that comparison. I guess the next step is to try to estimate the total number of clams and worms and their methane output and compare that to all cattle. Wild buffalo too? What about mountain goats? I mean, what’s the point?

rocketscientist
Reply to  Juice
October 13, 2017 3:57 pm

everybody poops.

Capn Mike
Reply to  Juice
October 13, 2017 6:57 pm

I keep thinking about those accounts of the American Plains being dark with limitless herds of Buffalo before the wicked white man came. Well, didn’t they fart? What about all that greenhouse gas? Was the climate sultry tropical in Nebraska before Buffalo Bill? That’s a serious question, BTW.

Reply to  Capn Mike
October 13, 2017 7:18 pm

Wild buffalo did not eat corn.

Griff
Reply to  Capn Mike
October 14, 2017 1:58 am

There is an argument that until the native population were decimated by European diseases, there weren’t any huge herds of buffalo.
Idea is buried in this long and thought provoking article somewhere https://www.theatlantic.com/magazine/archive/2002/03/1491/302445/?single_page=true

DB
Reply to  Capn Mike
October 14, 2017 3:35 am

Methane emissions from bison—An historic herd estimate for the North American Great Plains
Kelliher and Clark
http://www.sciencedirect.com/science/article/pii/S0168192309002846
Abstract:
Enteric methane (CH4) emissions were estimated from 30 M bison (Bison bison) across the North American Great Plains before contact with European settlers….
The historic herd’s emissions were 2.2 Tg CH4 per year. On 1 January 2008, 36.5 M cattle were located in 10 American states occupying the historic bison range. Cattle emissions were 2.5 Tg CH4 per year….

Samuel C Cogar
Reply to  Capn Mike
October 16, 2017 5:10 am

@ DB October 14, 2017 at 3:35 am

Enteric methane (CH4) emissions were estimated from 30 M bison (Bison bison) across the North American Great Plains before contact with European settlers….

Me thinks the 60 million estimate is more realistic, to wit:

30 – 60 Million: Estimated North American herd size prior to 1600.
https://bisoncentral.com/bison-by-the-numbers/

Anyway, we should not forget the CO2 emissions of literally billions of Passenger Pigeons, …… that would “darken” the sky during migrations, …….. that were once residents of North America before the influx of and contact with European immigrants.

Samuel C Cogar
Reply to  Capn Mike
October 16, 2017 5:23 am

There is an argument that until the native population were decimated by European diseases, there weren’t any huge herds of buffalo.

Only an “education deficient”, …… “bluntest crayon in the box” ….. or ….. a worst-case ”learning disabled” person would mimic such an asinine statement as noted above.

Reply to  Juice
October 14, 2017 1:57 am

Juice,
The point, apparently is that cows are on the bad creature list. Animal products that humans consume which result in CO2 or CH4 emissions. …….need to be cut back.
Unlike beneficial CO2 which is increasing and greening up the planet, it’s hard to make a similar case of beneficial CH4 to offset any negatives to modest global warming that has happened or if the busted global climate models used for political agend were right and there is going to be dangerous warming.

Uncle Gus
Reply to  Juice
October 14, 2017 5:47 am

Only man-made methane is actually *evil*. Natural methane, from free, unsullied natural animals may also cause global warming, but only the good kind.
You’ve got to learn to doubleplusgoodthink.

Michael S. Kelly
October 13, 2017 2:03 pm

But don’t clams sequester CO2 by taking it out of the water to form their calcium carbonate shells?

Gunga Din
Reply to  Michael S. Kelly
October 13, 2017 5:01 pm

Let them do that then nukem before the expel their last meal.

willhaas
October 13, 2017 2:05 pm

By far, the primary so called greenhouse gas released by the oceans is H2O. If you believe in a radiative greenhouse effect provided for by trace gases with LWIR absorption bands then the effect of all other so called greenhouse gases is trivial compared to that of H2O. But the reality is that a radiative greenhouse effect has not been observed anywhere in the solar system including the Earth. The radiative greenhouse effect is science fiction as is the AGW conjecture. In terms of heat trapping, the non-greenhouse gases are more prone to hold heat in the Earth’s atmosphere because they are such poor LWIR radiatiors to space. Heat energy transfer within the troposphere is dominated by conduction, convection, and H2O phase change and not LWIR absorption band radiation. This is all a matter of science.

The Reverend Badger
Reply to  willhaas
October 13, 2017 4:08 pm

Have you got a bot to copy/paste for you yet Will? It must feel like you are banging your head on a brick wall round here.
I would like to suggest to Anthony that we have one day a month where we SPECIFICALLY debate whether or not there is , or is not, such a thing as a GHG or GHG warming effect. This seems pretty fundamental to the (C)AGW debate.
Sure WUWT can be a broad church with some lukewarmers as well as NO-GHG adherents. But surely it would be both useful AND instructive to have a good debate about the science behind both trains of thought. We might all learn something fro it as there are clearly a lot of clever and qualified people on here.
How about it, Anthony ?

Samuel C Cogar
Reply to  The Reverend Badger
October 16, 2017 6:07 am

The Reverend Badger October 13, 2017 at 4:08 pm

I would like to suggest to Anthony that we have one day a month where we SPECIFICALLY debate whether or not there is , or is not, such a thing as a GHG or GHG warming effect.

Reverend B, doing said t’wouldn’t make one iota of difference simply because the lukewarmers, as well as many of the NO-GHG adherents …… will still harbor their adolescently nurtured AGW Religious belief and will not “give-it-up” out of an innate emotion “fear” that they will be in dire trouble iffen they do.

Uncle Gus
Reply to  willhaas
October 14, 2017 5:56 am

So, you’ve changed your ground.
I assume you Flat Greenhouse freaks have quit deliberately mixing up radiative *flux* with radiative *emmission*, and have started saying “Oh well, yes, there *is* such a thing as a radiative greenhouse effect. But it’s NOT IMPORTANT!”
(Anthony, you have not only serious scientists but actual geniuses attached to this blog. Couldn’t you get them organised to cream these weirdos? They make us look bad.)

Samuel C Cogar
Reply to  willhaas
October 16, 2017 5:49 am

The radiative greenhouse effect is science fiction as is the AGW conjecture.

Exactly right you are, Willhaas, ….. 100% fictional, like all nurtured Religious beliefs.
And “YES”, when one measures the temperature of the near-surface atmosphere they are ACTUALLY measuring the temperature of the non-greenhouse gases.

JohninRedding
October 13, 2017 2:12 pm

All this shows is nature is a bigger factor than anything man can do. Time for environmental wackos to get a life.

Bruce Cobb
October 13, 2017 2:17 pm

More importantly, how many angels can dance on the head of a pin, and for bonus points, how much CO2 and/or methane will they expel doing it? Science is fun.

Gary Pearse
October 13, 2017 2:18 pm

S’Truth! Okay, it is interesting but when they talk about amelioration of a natural source of methane, they reveal a sub 100 IQ!
comment image
We are talking about 1.8 ppm! If I knew the atmosphere had this amount and that it LEVELLED OFF with the PAUSE after 1998, I wouldn’t need to be a climate scientist to opine that it was mostly from the ocean. BTW, Science guys, this graph is independent support for the Pause, don cha know as are a number of other independent data sets.
Also the entire flatus of the world – kine, swine, lambs, clams, brines, canines, felines rams, dams… before 2007 has already converted itself into CO2. Oh and 38times less than one ppm is pretty close to zero effect with CO2 a little bit more than zero.

J
Reply to  Gary Pearse
October 13, 2017 2:35 pm

Can you find a copy of that graph with 10-12 more years of data?
I recall seeing one (probably here on WUWT) showing the methane pause is over, and the concentration is rising again.
2ppm is not much to worry about, especially given the shorter half life in the atmosphere.

Reply to  Gary Pearse
October 13, 2017 2:42 pm

Gary Pearse October 13, 2017 at 2:18 pm
We are talking about 1.8 ppm! If I knew the atmosphere had this amount and that it LEVELLED OFF with the PAUSE after 1998, I wouldn’t need to be a climate scientist to opine that it was mostly from the ocean.

Here’s the data you left off the graph, the missing 12 years don’t appear to support your idea of the pause.comment image

Gary Pearse
Reply to  Phil.
October 13, 2017 5:54 pm

You know that the pause has been temporarily interrupted by El Nino and you know that using parts per BILLION gives STEEP slopes? Oh and the 12years of “steep” rise is ~50PPB in total, or 1/20 of a ppm! That’s,… er… 4ppb/year! Let’s see, multiply this by the real equivalent number of about 20x CO2 strength and it makes 1ppm equivalent CO2. More over, in eight years, it it’s all converted CO2.
If CO2 is less than a third as effective a warmer (3x overwarming compared to observations), then methane is negligible. Oh, and the clams used a lot more CO2 in making their shells. Than the CO2 they emit.

D. J. Hawkins
Reply to  Gary Pearse
October 13, 2017 2:42 pm

To be fair, since about 2008 it’s been steadily increasing:
https://www.esrl.noaa.gov/gmd/webdata/ccgg/trends/ch4_trend_all_gl.pdf

rocketscientist
Reply to  D. J. Hawkins
October 13, 2017 4:04 pm

More greening…more dead wood…more termites?

Craig T
Reply to  Gary Pearse
October 13, 2017 11:36 pm

So the pause that started with the 1998 El Nino was interrupted by the 2016 El Nino? If 1999 to 2005 methane emissions independently supports the Pause then the emissions since 2005 support the end of the Pause. Well, that and the temperatures since Feb 2016.

Reply to  Gary Pearse
October 13, 2017 11:51 pm

Gary, there was a very slight increase of CH4 over the whole Holocene, probably due to the increase of rice cultivation by humans. The CH4 increase parallels the industrial years, with in the first years mainly from coal mining and in later years natural gas use. I don’t think that natural releases have much to do with it:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_ch4.jpg

October 13, 2017 2:33 pm

Digressing slightly, yet more evidence that the warmists’ CAGW/Climate Change theories are not matched by the ongoing evidence. In this case, the problem is not warming but cooling.
https://www.msn.com/en-gb/news/weather/thousands-of-tiny-baby-ad%c3%a9lie-penguin-starve-to-death-as-changing-weather-forces-parents-to-travel-for-food/ar-AAtn2mn?li=AA9SkIr&ocid=spartandhp.
Whole colonies of penguins in the Antarctic are dying off because of increasing sea ice. Apparently the same disaster happened only a few years ago.
Silly me, Climate Change can mean cooling; in other words any “change” in temperature, and both created by CO2 emissions. Who needs science, the warmist religion simply demands great faith from its followers!

Gabro
Reply to  macawber.
October 13, 2017 2:56 pm

Totally predictable that global warming would be blamed for extensive and thick West Antarctic sea ice.

Reply to  macawber.
October 13, 2017 4:05 pm

Macawber
It’s hilarious – do these people even know what they are saying??
“A colony of 18,000 pairs of Adélie penguins in Terre Adélie, Antarctica suffered the catastrophic breeding failure earlier this year, according to the WWF. The incident happened because unusually extensive sea ice forced their parents to travel further in search of food, leaving their chicks at home to starve, a reminder of the horrifying effects of the changing climate.”
What was horrifying and why? Was it horrifying to warmists that attention was drawn to growing, not shrinking, Antarctic ice?
Yes cooling is more “horrifying” than warming. So what conclusion does that lead to in regard to CO2?

AndyG55
Reply to  macawber.
October 14, 2017 12:39 pm

Yet Antarctic sea ice was at its lowest in many years, last year. DOH !!
(Currently pretty near its usual average peak extent.)
And look at the picture.. Where is all this sea ice?
Someone has been smoking penguin poop !!

commieBob
October 13, 2017 2:47 pm

The annual human emissions are around 0.1% of all the CO2 in the atmosphere. link For ease of arithmetic let’s suppose that humans have emitted the same amount of CO2 over the last 100 years (which they have not). That would mean that 10% of the CO2 in the atmosphere would have been contributed by humans. The problem is that atmospheric CO2 has increased from 290 ppm to 400 ppm. That’s an increase of 38%.
Humans have contributed way less than 10% of the CO2 in the atmosphere. The CO2 in the atmosphere has increased by 38%. Something else is causing atmospheric CO2 to increase.
We keep finding things like inconvenient worms that point out that we do not understand the CO2 cycle very well. ‘They’ claim they can do the budget within 1%. Bosh crap!
Am I missing something here? Burning fossil fuels does not explain the increase in atmospheric CO2. It could still be human caused, land use, pollution, etc. Even if higher CO2 were a problem, we would have to address the actual cause. Blaming coal is barking up the wrong tree. (Ain’t gonna get no possums if yer dog is barkin up the wrong tree.)

Reply to  commieBob
October 13, 2017 3:10 pm

commieBob October 13, 2017 at 2:47 pm
The annual human emissions are around 0.1% of all the CO2 in the atmosphere. link For ease of arithmetic let’s suppose that humans have emitted the same amount of CO2 over the last 100 years (which they have not). That would mean that 10% of the CO2 in the atmosphere would have been contributed by humans. The problem is that atmospheric CO2 has increased from 290 ppm to 400 ppm. That’s an increase of 38%.

Apparently you’re unable to read your own source which says that human emissions are around 1%, so your calculations are in error by a factor of ten!

Gabro
Reply to  Phil.
October 13, 2017 3:27 pm

Phil,
While you’re in the right ball park, the 1.11% cited for AD 2002 was as per the amount of CO2 in the air in AD 1750. There was about 40% more atmospheric CO2 in 2002 than in 1750, so based upon that link, the correct figure would be around 0.7% rather than 0.1 or 1.11%.
When you factor in that human fossil fuel burning added much less CO2 to the air in the first half of the last century than since then, there is still “missing” CO2. And like the missing heat, it obviously isn’t hiding in the oceans.

commieBob
Reply to  Phil.
October 13, 2017 4:02 pm

This link gives the annual human emissions at 29 GT, ie. 30 x 10^9 GT. The total atmospheric CO2 is 3 x 10^12 GT. That’s 1%, oops!

Reply to  commieBob
October 14, 2017 12:06 am

Commiebob,
Human emissions indeed are around 1% of what is already in the atmosphere, but the rest of your reasoning doesn’t hold:
If all that human CO2 remained in the atmosphere, the current CO2 level would be +80%, not +40%, as yearly (and total) human emissions are about twice the observed increase in the atmosphere.
In average some 50% of human emissions (as mass, not the original molecules) are removed into the sinks (vegetation and oceans).
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_emiss_increase.jpg
The removal of the extra CO2 above the ocean surface temperature driven equilibrium (290 ppmv in the atmosphere for the current ocean surface temperature) is slower than what humans emit each year and that is what remains in the atmosphere.
Ocean temperature increase since 1850 is about 0.8ºC, good for about 13 ppmv increase (16 ppmv/ºC over the past 800,000 years). The rest is from human emissions…

David S
October 13, 2017 2:47 pm

Methane is the main constituent of natural gas and it makes a great fuel. Isn’t there some way of collecting it and using it to run gas turbines or heat our homes? Each molecule of methane burned produces one molecule of CO2 which is 38 times less effective as a greenhouse gas. Seems like a win win situation.

Gabro
Reply to  David S
October 13, 2017 3:06 pm

Ah, but what of the water vapor?
CH4 + 2 O2 –> CO2 + 2 H2O
I know, still less effective at retarding radiation than methane. Those short (wave) bus, slow photons really get bullied by those big, mean diatomic, three-atom molecules!

Gary Pearse
Reply to  Gabro
October 13, 2017 6:08 pm

Gabro , if burning methane increases manmade H20, it causes natural water vapor to condense because the water in the atmosphere is in equilibrium with ocean and other sources. Theoretically, relative humidity is ~constant.

rocketscientist
Reply to  David S
October 13, 2017 4:10 pm

Yeah its called Biogas. It’s produced in many parts of the world.
https://en.wikipedia.org/wiki/Biogas

rocketscientist
Reply to  David S
October 13, 2017 4:14 pm

Our were you suggesting some how capturing the methane as it exits the livestock?
um…I’ll let you hold the hose.

Reply to  David S
October 14, 2017 10:41 am
gwan
October 13, 2017 3:02 pm

Cows have no effect on climate .
The rough estimates are that about 100 million tonnes of methane is emitted from farmed livestock each year .
The total methane emitted into the atmosphere from all sources is about 600 million tonnes
Methane levels in the atmosphere are slowly rising at the moment by about 10 million tonnes per year .
The calculation is that at least 590 million tonnes is broken down into CO2 and water vapor each year in the upper atmosphere .
The average life of methane in the atmosphere is 8.4 years .
The CO2 and water is absorbed by vegetation and with photosynthesis carbohydrates are formed which is the basis of all life on earth.
Ruminant livestock are vegetarians and as they consume plant matter a small amount of methane is released mainly through belching .
The methane that the cows belch comes from the bacteria in the cows stomachs that digest the plant material in anaerobic conditions ( in the absence of oxygen ) and then the bacteria pass to the next stomach where they are absorbed as food for the cow .
The methane is a cycle from cow to the atmosphere then broken down into CO2 which is absorbed by vegetation then eaten by cows .
CO2 contains one atom of carbon and two atoms of oxygen .
CH4 contains one atom of carbon and four atoms of hydrogen .
Therefore no more carbon is added to the atmosphere .
Methane in the atmosphere is said to have 25 times the global warming potential of CO2 but the cows are not ADDING any extra methane to the mix .
Methane is very slowly rising in after a leveling off around the turn of the century. The rise is not coming from livestock .
Some of the rise is probably natural but some would be emitted from gas fields and installations and coal mining is a large emitter and of course transport fuels with more traffic on all roads .
How did cows get the blame ?
I was told on good authority that the first and second global warming summits in Austria and Brazil by John Maunder who attended both summits as a delegate that methane from livestock was never mentioned .This was introduced at Kyoto and it has never been questioned .
Why has it never been challenged .
There are activists in the UN who have the notion that livestock are degrading the planet .They probably are vegetarians but have they tried living on grass salad .Livestock turn low quality forage into high quality protein to feed the world .
New Zealand has of 4.6 million people and we export enough food to feed 45 million people mainly high quality protein from farmed animals .

Derek Colman
Reply to  gwan
October 13, 2017 5:05 pm

Looking forward to eating more of that delicious NZ lamb here in the UK like we did in the old days, once Brexit goes through, and it becomes affordable again without EU protectionist tariffs.
As for the subject in hand, before we turned large tracts of land into dairy and beef farms, those lands were inhabited by large herds of ruminant animals, both on the plains and in the forests. These greenies banging on about methane from cattle seem to forget that. Have we really increased the amount of methane produced, or just changed the source of it?

Barbara
Reply to  Derek Colman
October 13, 2017 6:45 pm

CNN.com, Nov. 10, 1999
“Don’t forget methane climate experts say”
“World leaders established the Kyoto Protocol in 1997 to create standards to stabilize six greenhouse gases in order to lessen global climate warming.”
More at:
http://cnn.com/NATURE/9911/10/methane.enn

Edwin
Reply to  gwan
October 13, 2017 5:29 pm

Do all the ungulates that humans raise equal all the ungulates that existed on the Great Plains of North America, plains of Africa or the steppes of Eurasia? I have had this debate with far left environmentalists, usually not just vegetarians but radical vegans. Only one ever admitted that they had not thought about that, but still argued that cows were bad. Cows were worst than sheep and goats for some reason in their minds. As for aquaculturing shellfish and causing extraordinary methane production, most of the aquacultured shellfish are primarily replacing long depleted natural stocks. At the turn of the 20th Century there were enough oysters in Chesapeake Bay to filter all the water in the bay several times a day. Now the oysters are so depleted that it would take weeks or months to filter the water once. All the bays in the Florida Panhandle, especially Apalachicola, also had very larger oyster populations that are now a remanent of what existed in the 1930s.

Matthew R. Epp P.E.
October 13, 2017 3:36 pm

Just curious if anyone on here knows. How much methane is released into the atmosphere by treating sanitary sewage at the 10’s of 1,000’s of sewer treatment plants in the USA?
How much methane is released through ventilation of the millions of septic tanks?
The sewer systems are sized based on 100-200 GPD/ person depending upon locality, septic systems at 2000 GPD for average sized family.
What is the best estimate for the amount of solid/ sludge that is anaerobically digested creating methane? I’ve read a few articles on line, but most of them are talking about biogas to generate electricity for X many homes, etc., without discussing gas composition, concentrations, amount of sludge converted to gad in digestion, etc.
My thinking is we humans generate far more “ass gas” through treatment of effluent than the cows and shellfish worms, etc. combined.
Thoughts?

Matthew R. Epp P.E.
Reply to  Matthew R. Epp P.E.
October 13, 2017 4:23 pm

If you keep looking, a study appears.
http://users.ugent.be/~evolcke/pdf/2012_Daelman_WaterRes_MethaneEmissionsFromMunicipalWWtreatment.pdf
According to study (paragraph 2.1) “The plant treats the domestic wastewater of 360,000 population
equivalents” (PE) and generates (paragraph 3.1) “The daily average methane emission from the entire treatment plant at Kralingseveer during the measuring campaign (from 14 October 2010 until 28 September 2011) was 302 kg CH4/ day, with a standard deviation of 83 kg CH4/day”
302kg + 83kg = 385 kg/day divide by 360,000 PE = 1.069g/day/ PE
302kg – 83kg = 219 kg/day divide by 360,000 = 0.608g/day/PE
This data was collected from the Kralingseveer WWTP in the Netherlands.
“Assuming” comparable numbers for “average” USA (gotta love weasel words), with a population of 330 million
330,000,000 PE x 1.069 g/PE/day x 365 days/ year = 128,700,000,000 g/year = 128,700 Tonnes
330,000,000 PE x 0.608 g/PE/day x 365 days/year = 73,200,000,000 g/ year = 73,200 Tonnes
Based on the numbers from @gwan(posted above) My assumptions are full of “ass gas” source material.
***Please note PE in the calculations refers to Person Equivalents, not Professional Engineer, although we tend to be full of disproportionate amounts of source material***
Matthew R. Epp PE

Gary Pearse
Reply to  Matthew R. Epp P.E.
October 13, 2017 6:15 pm

Still negligible at under 2ppm total in the atmosphere and added 4ppb (PARTS PER BILLION) /yr over the past 12yrs, after a pause of about a dozen years. Storm in a tea cup.

October 13, 2017 3:39 pm

What about the output of humans? I’m a serious contributor…

Reply to  John
October 13, 2017 4:01 pm

One good fart is worth nine doctors – Old Yugoslav saying

John M. Ware
October 13, 2017 4:03 pm

What I get from this article and the comments is that there is a lot of “greenhouse gas” besides human-generated CO2. This additional gas has been produced by animals and other sources for as far back as our history goes. So far, the total effect has been negligible, as far as actual scientific evidence can show. (Actually, I like “nugatory” better than “negligible.” It sounds so learned.) In any event, showing that clams, mussels, and their ilk fart or otherwise exude methane or CO2 or any other greenhouse gas doesn’t worry me in the least. In fact, I’m glad the little critters are keeping busy; it must make their lives seem more worthwhile. The more sources of greenhouse gas are found, the less significant the already nugatory CO2 concentration becomes.

Gary Pearse
Reply to  John M. Ware
October 13, 2017 6:18 pm

What claims release is negligible compared to the CO2 they take in to make their carbonate shells whole they are living. Very bad science.

michael hart
October 13, 2017 4:26 pm

The methane-from-cows catastrophe is another scare story that never passed the smell test (pardon the pun). The organisms and chemical processes that occur at the base of the ecological pyramid have significant methane fluxes. Their total scale is vast. To imagine that a relatively small number of large herbivores sitting near the top of the same pyramid of life can dominate all the processes underneath, defies most versions of experienced reality in chemistry and biology.
It is a classical example of simplistic environmentalist calculations that inflate the importance of certain specific quantities, while ignoring the relatively large uncertainties in other quantities that actually comprise “the elephant in the room”. The dishonest and the incompetent love uncertainty when it can apparently be made to work in favor of a pre-determined result.

Gary Pearse
Reply to  michael hart
October 13, 2017 6:30 pm

Yeah, we should be congratulated for killing off the woolley mammoth, mastodons, poaching elephants and rhinos and the prairie buffalo. We just replaced them with beef. The IPCC should have an award for hunting game, getting our meat and mitigating climate change.
Real science and engineering understands mass balance. Farting clams let off carbon but take in more in making their shells. Using hardwood pellets to replace coal in UK is done because new trees will grow and pick up all the carbon. For the cow, it’s exactly the same. The grass they eat takes up more than the farts they release. It’s all kindergarten science and they don’t know it.

Gabro
Reply to  Gary Pearse
October 13, 2017 6:37 pm

Except that burning wood releases more CO2 than coal, coal more than oil and oil more than gas. The ratio of H to C goes up with each fuel.

Reply to  michael hart
October 14, 2017 4:41 am

Remember the Gillard Government in Australia that said it would prevent Climate Change? The Gillard government promoted and enacted a Carbon Tax on fuel used in Australia, while Australia mines and exports millions of tons of Coal each year to China to be used as fuel. Apparently the irony escaped them. Then these Aussie geniuses decided that they should exterminate all the camels that roam wild in Australia, because camels produce methane in their farts.
Gillard and her cohorts were turfed in the next election, and the Carbon Tax was repealed. Last I heard, there remain many camels roaming the outback.

Uncle Gus
Reply to  Al Tinfoil
October 14, 2017 6:08 am

It’s surprising how often these greenards’ obsessions move around to killing something…

CRS, DrPH
October 13, 2017 4:26 pm

Few mention wetlands as a source of methane emissions, please see this graphic: comment image
I learned about this in the 1980s from Dr. Anita Baker-Blocker of University of Illinois, and it stayed with me all these years. Of course, wetlands are good for waterfowl, recharging aquifers etc., but bad for methane production.
Can’t make an omelet without breaking eggs.

Gabro
Reply to  CRS, DrPH
October 13, 2017 5:00 pm

Why does it not surprise me that “climate scientists” haven’t heard of swamp gas?

gwan
Reply to  CRS, DrPH
October 13, 2017 6:10 pm

Thats one of the reasons Trump wants to drain the swamp

October 13, 2017 4:39 pm

Can no one get on top of the out of control farting of those pesky worms, clam and termites for us before we are totally stunk out?

Earthling2
Reply to  ntesdorf
October 14, 2017 8:12 pm

That is part of why the seaside smells so great along with the salty windy ocean spray and decomposing plant and animal life. It is all natural and all good. How did CO2 and Methane get such a bad rap, especially making the climate so terrible? Actually, the climate is rarely as optimum as it has been the last 150 years, enabling billions of people to be born practically overnight. Most of the last 2.6 million years has been in a deep ice age with some short sporadic interglacials in the NH. This is as good as it gets. Thanks to warmth and CO2/CH4.

Gunga Din
October 13, 2017 5:04 pm

CO2 was the excuse for “The War on Coal”.
Will Methane be the excuse for “The War on Beans”?

AndyG55
October 13, 2017 6:00 pm

Really is a bit silly, isn’t it.
Its all just part of the CARBON CYCLE that is ABSOLUTELY ESSENTIAL to everything living thing on this miraculous planet of ours.
Just like COAL is part of the carbon cycle, releasing accidentally sequestered carbon back into the cycle that keeps the world ALIVE !!
Without CARBON and the CARBON CYCLE………. that’s it . folks !!

Phil R
October 13, 2017 8:54 pm

Anthony,
May be slightly OT and not sure where else to post (and late Friday after a couple bevvies), but just wondering who does the graphics/picks the photos for the thread? I was wondering if someone could take this cow, reverse the photo, and combine it with the one with Algore flaming the earth (cow flaming Algore). Now, that would be funny right there…

J Mac
October 13, 2017 9:16 pm

Remain clam! The planet ain’t gonna overheat because of buffalo methane flatulence or CO2 plant food!
You gotta be really gullible to believe the planet is ‘endangered’ by the essentials of life!

J.H.
October 13, 2017 10:14 pm

Worms, Clams destroying the Earth! That’s it…. We’re going to have to Nuke it from Orbit. It’s the only way to be sure.

J.H.
October 13, 2017 10:16 pm

… aw forgot the link…. https://www.youtube.com/watch?v=aCbfMkh940Q

Reply to  J.H.
October 14, 2017 1:51 pm

But that would be dangerous.
Here’s the safe way.

October 13, 2017 10:20 pm

…. methane has 28 times greater warming potential than carbon dioxide.

Every time this meaningless statistic is brought up people need to ask what it means in terms of increasing global temperature? The answer is not very much. A doubling of CH4 might run temperature up a few hundredths of a degree – maybe.
A doubling of methane would be an increase of around 2 ppm and a similar increase of 2 ppm of CO2 won’t run temperatures up by any measureable amount. In other words nothing, and 28 times nothing is nothing.

gwan
Reply to  Steve Case
October 13, 2017 11:41 pm

Steve Case
That is why I have challenged anyone to bring forward proof that methane from livestock can warm the planet by more than .05 degrees C over the next 20 years .I will then get the evidence peer reviewed .
I have had no takers yet only a few dumb statements

Griff
October 14, 2017 1:59 am

There has not, in recent geologic time, been an increase in worms etc excreting methane
There has been an increase in domestic cattle, methane from fracking and CO2 from vehicles and power stations

gwan
Reply to  Griff
October 14, 2017 4:39 am

Another dumb statement Griff ,
Methane is measured in parts per billion in the atmosphere because 1.9 parts per million does not sound very scary ..In the last 40 years methane has increased by .one third of one part of one millionth of the atmosphere . Probably within the error bars of the measuring instruments and sampling methods .Back in the nineties there was rumored that methane was leaking from gas pipes and gas fields in Russia after the fall of the Iron curtain.Canadians in the far north were getting readings across the Arctic .The rise in methane slowed for a few years but it has moved up again .It is non problem as it is broken down into CO2 and H2O and most of the methane has come from natural causes and I include livestock emissions as natural .And the carbon cycle keeps on working as if humans could intervene
See my posting above .

AndyG55
Reply to  Griff
October 14, 2017 11:02 am

“not…..been an increase in worms”
And you know this? how?
You are just MAKING UP NON FACTS, like you always do.

October 14, 2017 3:53 am

Griff October 14, 2017 at 1:59 am
There has not, in recent geologic time, been an increase in worms etc excreting methane
There has been an increase in domestic cattle, methane from fracking and CO2 from vehicles and power stations

So what? How much is that increase in methane going to run up global temperature?

Uncle Gus
October 14, 2017 5:58 am

Let us not forget…
The Global Warming Cowfart Panic started out as a *joke*…

The Original Mike M
Reply to  Uncle Gus
October 14, 2017 8:06 am

Look how many people actually believed the Russian spoof that the Belgian government had helicopters flying around to monitor backyard charcoal barbecues? https://sputniknews.com/world/2007040362999935/

The Original Mike M
October 14, 2017 7:59 am

Nature is not just keeping up with our rate of increase of carbon emissions – it is exceeding that rate at the moment according to this study – https://www.nature.com/articles/ncomms13428

The continued enhancement of the terrestrial carbon sink during the recent slowdown in global warming led to a pause in the atmospheric CO2 growth rate, and a decline in the fraction of anthropogenic emissions that remains in the atmosphere.

The more carbon we add – the more life is responding to it by pumping up the carbon cycle. Nature appears to welcome having more carbon whether it’s from CO2 or methane.

ddpalmer
October 16, 2017 10:11 am

So, if there are “ridiculous amounts of greenhouse gases to the atmosphere that is unaccounted for” and the models (that don’t account for this) are already running too hot. Then if the models DID account for this ‘ridiculous amount’ they would be even more wrong!
I think any logical person would have to conclude that if models missing a ‘significant amount’ of GHG emissions are already too hot, then the current models are significantly wrong (dare I say they are significantly insignificant), and/or the entire AGW theory is wrong.

HK
October 16, 2017 4:21 pm

By stating that the Baltic Sea represents 0.1% of the Earth’s oceans, it can be quickly extrapolated that these creatures release GHGs equivalent to 20 million cattle. But this dramatic result is not backed up by the literature, as it does not claim or suggest that these macrofaunae are present in the same population consistently across the globe. Additionally, cattle populations have been steadily increasing with human populations while crustaceous populations are not farmed on such a large scale. Finally, GHGs released “naturally” are a part of the carbon cycle, essential to life on Earth, however, humanity’s excessive production of GHG’s from cattle farming goes far beyond this natural cycle’s limits. It does not make sense to suggest that climate change is not caused by humans by proving that other animals also release GHGs. If these clams and worms were releasing amounts exceeding all human activity, then it would be a cause for concern, but as it seems these releases barely meet the output of 1% of the UKs cattle population.

Steve Zell
October 16, 2017 4:43 pm

[Quote from the article] “The authors warn that stakeholders should consider these potential impacts before deciding whether to promote shellfish farming to large areas of the ocean.”
That shouldn’t be too much of a problem. Shellfish are currently only “farmed” in shallow water near the coasts, where it is not too difficult to harvest the shellfish. A comparison of the volume (1.335 billion km^3) and surface area (362 million km^2) of the world’s oceans shows that the average depth of the oceans would be about 3.7 km, so that most of the area of the oceans is much too deep to allow practical “farming” of bottom-dwelling shellfish.
[Quote from the article]“What is puzzling is that the Baltic Sea makes up only about 0.1% of Earth’s oceans, implying that globally, apparently harmless bivalve animals at the bottom of the world’s oceans may in fact be contributing ridiculous amounts of greenhouse gases to the atmosphere that is unaccounted for.”
The Baltic Sea has a relatively long coastline for a relatively small surface area, meaning that most of its water is relatively shallow. If the Baltic Sea represents only 0.1% of the surface area of the Earth’s oceans, the methane production of its bivalves cannot be extrapolated to the vast area of the much deeper Pacific, Indian, and Atlantic Oceans. Clams and worms cannot survive at the bottom of deep oceans, because the sun doesn’t penetrate to that depth, and there would be much less food supply (plankton) for them than in the shallow waters where they thrive.