Guest essay by Phillip Mulholland
Late Carboniferous to Early Permian time (315 mya — 270 mya) is the only time period in the last 600 million years when both atmospheric CO2 and temperatures were as low as they are today (Quaternary Period ). Temperature after C.R. Scotese http://www.scotese.com/climate.htmCO2 after R.A. Berner, 2001 (GEOCARB III) 
In a previous thread on WUWT published on 13 September titled Claim: atmosphere heats the oceans, melts Antarctic ice shelf, Sridhar Anandakrishnan, Professor of Geosciences, at Penn State is reported as saying:-
“Eventually, with all that atmospheric heat, the oceans will heat up.”
Well, that statement may or may not be true, but one thing we can be certain about, it does not apply to the seas around Antarctica.
A former colleague of mine had on the wall of his office a standard map of the World with the continents coloured by surface elevation. Unusually his map showed the icecaps of Greenland and Antarctica, not as featureless white regions, but instead coloured by the true elevation of the ice surface. What his map showed is the dramatic height of this surface, both over the bulk of Greenland and also over the vast majority of Antarctica, with layers of ice piled high into the atmosphere forming a plateau as tall as the mountain ranges of other continents.
His map demonstrated why Antarctica at 2,500m has the greatest average surface elevation of all the continents. With its high surface elevation that reaches a plateau maximum at Dome A of just over 4,000 metres, Antarctica stands taller in the atmosphere than any other landmass. With thin dry transparent air above it and the long months of the Austral winter, the ice surface of Antarctica acts as a gigantic thermal radiator that short circuits the atmospheric greenhouse effect and exhausts surface radiant energy directly into Space.
Throughout the winter season of darkness in Antarctica the thermal cooling of the ice surface generates copious amounts of cold dry dense air, this bitterly cold tropospheric air flows north off the icecap towards the Southern Ocean, descending to sea level as a gale force katabatic wind. The wind that Captain Scott referred to when he wrote “Great God this is an awful place”.
When the dense cold air reaches the coast at the Weddell Sea, its temperature is sufficiently low to flash freeze any open surface sea water, but the wind’s continuous force directs any newly formed ice north, away from the coast, creating a permanent open water gap The Latent Heat Polynya.
Oxygen is a reactive gas vital for the survival of animal life. In the oceans, oxygen can only be created either by biological activity in the surface waters of the photic zone or be directly dissolved from the atmosphere by the turbulent mixing of surface waves. In the planetary ocean sea water is layered by density and cold dense water is found throughout the bulk of the modern deep ocean. One of the challenges for Oceanography is to explain the presence and distribution of dissolved oxygen gas in the ocean deeps, given that it cannot have been formed there.
The explanation for the presence of this deep ocean oxygen lies in the existence of the Latent Heat Polynya in the Weddell Sea and elsewhere along the coast of Antarctica. Here, in the polynya, cold dense sea water is created, chilled and oxygenated by the katabatic winds of Antarctica and salted by the key process of brine rejection – dense salty water expelled from the continuously formed sea ice. This chilled sea water descends into the ocean as a gravity driven flow of high salinity brine that carries the dissolved oxygen vital for deep marine life down into the ocean depths. Truly it can be said that the polar icecaps are the lungs of the deep ocean.
The current climate paradigm recognises two distinct and separate states for world climate, the Icehouse World and the Greenhouse World. The Icehouse World is characterised by low atmospheric carbon dioxide levels, cold ocean deeps with high levels of dissolved oxygen and of course, polar continental icecaps with consequent low global sea levels. The Greenhouse World by contrast is characterised by high atmospheric carbon dioxide levels, warm ocean deeps with low levels of dissolved oxygen, no polar continental icecaps and therefore high global sea levels.
Geology shows us that in the past during the Cretaceous period, at a time when the world did not have any polar continental icecaps and global sea levels were high, the ocean deeps were filled with warm +15C dense salty oxygen-poor water creating the required conditions for global marine anoxia and the deposition of Sapropel, (biological carbon) in deep ocean muds of, for example, the Cretaceous Boreal Ocean. The implication here is clear, because warm sea water has a low dissolved gas carrying capacity, anoxia is preferentially associated with warm world conditions and the presence of sapropel in the Geological record is considered to be diagnostic of a Greenhouse World.
This dichotomy is a fundamental tenet of climate science. That climate can be in one state, either global cold – the Modern world, or global warmth – the Cretaceous world, but not in both states simultaneously. However this tenet is wrong and Geology proves that it is wrong. It is indeed possible to have a world with a massive continental polar ice cap, an Icehouse World diagnostic, and simultaneously anoxic prone warm water ocean deeps, a Greenhouse World diagnostic, and that world was the Carboniferous period.
Imagine a world with no South Atlantic Ocean, instead South America is joined directly to Africa, a world with no Southern Ocean, instead Antarctica is joined directly to Australia and also no Indian Ocean with instead the Indian landmass (along with Madagascar) filling the jigsaw puzzle gap between South America/Africa/Arabia and Australia/Antarctica. This southern continent is called Gondwana by Geologists. Imagine this gigantic Gondwana continent covered with an ice sheet that at its maximum extended from the South Pole across an area equivalent to all of Antarctica, Southern Australia, India, Madagascar, south & east Africa and southern South America combined. This continental icecap existed throughout the Carboniferous period. The modern world’s single polar ice continent of Antarctica is puny in size compared to this ice monster.
Victorian geologists were very interested in the Carboniferous period; the coal won from these rocks powered their industrial world. Studies of the Carboniferous strata in north Yorkshire demonstrated the existence of Cyclothems, repeated patterns of marine sedimentation that start with a coal seam, the remains of an equatorial forest being drowned and then often overlain by marine limestone. The limestones were then in turn overlain by river delta sediments as the coast moved seaward and the shallow sea retreated. Eventually the swamp forests regrew and another coal seam was created. The Victorians recognised that this rhythmic depositional cycle seen in the Yoredale deposits of Yorkshire was controlled by eustatic sea level change. That is global sea level variations controlled by the waxing and waning of a major continental icecap. We now know that the icecap responsible for the Carboniferous cyclothems was located on the Gondwana continent.
So the deep oceans of the Carboniferous world were filled with cold oxygenated seawater created by the katabatic winds of the Gondwana icecap, just like those from the modern world’s Antarctica? Well no actually the deep ocean of the Carboniferous world was anoxic just like the later Cretaceous ocean. Again thanks to the Victorian geologists who studied the Culm deposits of Devon they recognised that the Carboniferous Culm contained radiolarian chert, pseudomorphs of calcite and abundant organic carbon. They concluded correctly that Culm was a deep ocean deposit, and although they did not recognise the true size of the ocean they were studying, we know because of their work, that the muds were bathyal sediments deposited below the carbonate compensation depth far from land. The carbon content of Culm proves that the Carboniferous world ocean was anoxic and that abundant marine sapropel was created and deposited in Carboniferous marine sediments which now form part of the oil and gas shale resource which supplies the hydrocarbon fuel used to power our modern industry and commerce.
So how can we resolve this paradox of the Carboniferous with its simultaneous continental icecap of Gondwana and an anoxia prone global ocean? In Geology, the present is often the key to the past, and we have a key to unlock this conundrum. That key is the modern Red Sea.
The Red Sea is situated in the northern hemisphere tropics between Africa and Arabia. Under modern climatic conditions, located beneath the Hadley Cell, the Red Sea experiences high insolation, high evaporation and low fresh water input. These features combine to produce a Red Sea marine bottom water with the highest temperature (21.7C) and salinity (40.6 psu) in the modern world, even with its current low carbon dioxide atmospheric conditions.
Although the outflow volume of Red Sea high temperature bottom water into the Indian Ocean does not impact the modern deep water temperatures of the World Ocean, the key point is that Red Sea deep water produced under a modern tropical climate has a higher density at 1028.579 kg/m3 than any of the cold deep water currently produced in Antarctica by the modern world’s polar climate. For example Antarctic Bottom Water has a minimum temperature of -0.8C, a peak salinity of 34.6 psu and a consequent density of 1027.880 kg/m3.
If these two bottom waters, cold oxygenated polar deep water and warm high salinity low-oxygen carrying tropical bottom water, were allowed to meet, the density stratification principle requires that the densest marine water will occupy the deepest part of the ocean. Red Sea bottom water is denser than the coldest water Antarctica can produce. In a straight contest between the Red Sea and the Weddell Sea, the Red Sea wins every time.
So consider now the Carboniferous period with its shallow tropical seas and vast coastal equatorial coal swamps and remember that half of the surface area of our planet is located between 30 degrees North and 30 degrees South. The shallow seas of the tropics are huge solar energy collectors producing warm dense marine brines. Even in the Carboniferous with its gigantic Gondwana icecap the world was warm because in Oceanography marine water salinity trumps marine water temperature every time.
The Carboniferous shows us that with open ocean conditions the natural state of the world’s climate is as follows-
A polar continental icecap that produces cold oxygenated mid-level ocean water. This sea water is less dense and therefore is layered above the warm dense saline and anoxia-prone tropical water of the bathyal ocean depths.
I leave you with this conclusion. The Carboniferous was a warm ocean world, with low gas solubility in the deep sea. This produced an atmosphere suitable for land plants as they had an abundance of carbon dioxide gas to consume. Not for nothing does this period of Earth’s geological history have as its name the Carboniferous and yet in the mid-ocean above the deep abyssal anoxia, the pelagic fish also had an abundance of dissolved oxygen to breathe thanks to the presence of the Gondwana icecap and its coastal latent heat polynya.
This essay proposes that a fundamental tenet of climate science, that the world’s climate can be in one of two separate and distinct modes, either the Icehouse world or the Greenhouse world, is false.
Hi. A quick google/facebook search reveals that Mr. Mulholland is a very private person. Can anyone post a quick Resume for Mr. Mulholland?
grumpyoldmanuk says:
October 6, 2013 at 9:53 am
Hi. A quick google/facebook search reveals that Mr. Mulholland is a very private person. Can anyone post a quick Resume for Mr. Mulholland?
Is it difficult taking the facts in from what is written and referenced without knowing the writer? There is a reason that the author of ‘The emperors new clothes’ chose a child to be the one to point out the fallacy and not a revered academic.
http://governmentshutdown.noaa.gov/
Panic over “Only web sites necessary to protect lives and property will be maintained.”
(;>)
In case others were as interested by that presentation you described of the elevation including ice caps, this makes the point nicely: http://upload.wikimedia.org/wikipedia/commons/thumb/9/93/Elevation.jpg/1280px-Elevation.jpg
With this legend: http://upload.wikimedia.org/wikipedia/commons/9/90/Elevationscale.JPG
Though this also puts things in a better perspective, showing only the “interesting” high elevations in lighter colors: http://upload.wikimedia.org/wikipedia/commons/thumb/1/15/Srtm_ramp2.world.21600×10800.jpg/1280px-Srtm_ramp2.world.21600×10800.jpg
Makes sense to me.
What a fascinating essay. Thanks.
Ian W says:
October 6, 2013 at 10:03 am
“Is it difficult taking the facts in from what is written and referenced without knowing the writer? There is a reason that the author of ‘The emperors new clothes’ chose a child to be the one to point out the fallacy and not a revered academic.”
I found the paper a compelling read which agreed with my preconceptions and prejudices . The next stage is to test the background of the writer to aid in forming an opinion. The estimable Mr Eschenbach frequently points out the Emporer’s nakedness and is far from a revered academic, but I’ve got to know and trust his writings over the years. Mr Mulholland is not known to me, so I’m asking the question. If you can nose give me a proper answer, I’d be grateful.
Mr.
Obviously the government shutdown is only affecting information as the web site needed to provide that warning could, if desired, provide useful information. The character of your leadership is revealed by how they prioritize in a crisis.
Back to the topic – does the adiabatic heating of the katabatic wind result in a transfer of energy between the continental interior and the surrounding atmosphere/ocean or is that a net zero sum?
I think too that katabatic winds take on the same characteristics as a long runout land slide (such as that which buried Pompei) at some point, existing on inertia alone to move “the last mile” or so. There should be signature atmospheric pressure waves in such a process. “The last mile” as suggested here is an unquantified but finite distance used to populate a problem/solution set in communication and power distribution engineering.
The ultimate irony is that the hydrocarbons we use today, the source of all this teeth gnashing, were created during much more warmer lusher periods, when the biosphere was much more productive than it is today.
I have a bumper sticker on my SUV that says: Powered by Naturally Occurring Bio-fuel
I know who Mr Mulholland is. He is a guy who writes some very interesting stuff
Philip, a thoroughly enjoyable article, with references to a name we have all heard of (Cpt. Scott). Basically what you are saying is that the climate of the Earth has more complex features than just CO2? The graph shows absolutely no correlation with CO2 levels and global temperature, or that CAGW, which according to the experts should be inevitable at 1000ppm/CO2, has not happened 400 million years ago, so is unlikely to happen in the future.
Are you also saying that without at least one mountainous polar cap, life on Earth would have impossible, this would imply that life on other planets without the same land mass conditions would be impossible too?
The ocean currents, wind currents and continents were all in different places than now.You cannot, then, compare the two.
Plants evolved because of the high C content. That’s why the CO2 falls in the Devonian. There were no humans cuttiing down these trees, so CO2 fell.It is the very presence of the ice caps that keeps the ocean currents circulation, and ensured the great blossoming of the Devonian, and life today.If we continue to pump out fossil CO2 by burning carbon stored millions of years ago we will raise global temperatures and lose these icecaps, and the icehouse world or the greenhouse world will happen.We have gone from 280 PPM CO2 to 380 PPM in 200 years. The icehouse and Greenhouse happen anyway, because of the Earth’s movement through space.Just every few million years.The O2 in the bottom of the oceans is there because of cold water sinking and hot water rising.And as the article says, salinity. But dump in lots of fresh water from melting ice, and that salinity decreases. You say that’s not important, but If the denser, warmer and less O2 concentrated and more saline water drops to the bottom (it contains less O2 so supports less life) then ocean anoxia SURELY follows in the oceans . If the icecaps are the lungs of the earth, shouldn’t we be doing everything we can to stop producing CO2 and increasing temperatures which mean the loss of ice and ultimately, the loss of life; When the currents change, the wind changes, the climatic zones change, and the climate changes. Simples! Currents will change when they warm or become cooler, or more/less salty.
Even if all the scientists are wrong, isn’t it better to have a cleaner planet? In the end, the pollution will cause population crashes, as Malthus observed.
grumpyoldmanuk says:
October 6, 2013 at 10:32 am
” The next stage is to test the background of the writer to aid in forming an opinion.”
Not really if you believe it believe it… if you don’t don’t… if your unsure CHECK FOR YOUR SELF. Your line of thinking is called the logic fallacy of the appeal to authority. First check his facts then worry about who he is.
OMG, check the graphic I created by reconstruction in 2005
http://www.kogagrove.org/sams/agw/images/paleomap.png
From my site:http://www.kogagrove.org/sams/agw/agwmain.html
idreamofthought,
Sorry, but the planet says your conjecture is wrong.
As CO2 continues to rise, global temperature continues to decline.
Thank you for this great post.
temp says:
Your line of thinking is called the logic fallacy of the appeal to authority.
===========
agreed. the expert, knowing 1000*N/infinity about their subject, imagines they are much more capable to predict the future as compared to the amateur that only knows N/infinity about their subject.
the amateur at least has the common sense to recognize that N/infinity is very close to 0%, while the expert mistakenly believes that 1000*N/infinity is very close to 100%. It is this mistaken estimate on the part of the expert that routinely leads science astray.
this article also makes no sense to me.
cor, this article makes sense to me.
But are the mixed conditions of Carboniferous, as described, only possible with a “Gondwana sized” continent in that location relative to the equator? Probably not, …..but wondering nonetheless.
“I have a bumper sticker on my SUV that says: Powered by Naturally Occurring Bio-fuel”
I would say that’s its more Powered by sun energy, old or New?
Before I believe that story, a credible explanation should be given about the process converting organic sediments, basically carbohydrates to hydrocarbons close to thermodynamic equilibrium, which invariably occurs in buried sediment layers. That chemical process just would not happen spontaneously with no free energy input whatsoever, not even in hundreds of million years. Chemical potential of organic matter is too low for it compared to that of hydrocarbons.
idreamofthought says:
“Even if all the scientists are wrong, isn’t it better to have a cleaner planet? In the end, the pollution will cause population crashes, as Malthus observed.”
If by pollution you mean CO2, how will increased greening of the planet make it less “clean” or cause the population to crash? It is higher energy costs caused by the attempt to limit CO2 that will harm the population. Your Malthus theories are misplaced nonsense. Dream on.
idreamofthought says:
October 6, 2013 at 10:58 am
“Even if all the scientists are wrong, isn’t it better to have a cleaner planet? In the end, the pollution will cause population crashes, as Malthus observed.”
How did Malthus observe something that WILL happen?
DirkH
So many people have the strange disconnect that we humans are not part of nature. We are, and who is to say what we are doing on this planet is not part of nature and it’s unknown future outcome?
@Berényi Péter 12:03 pm
Chemical potential of organic matter is too low for it compared to that of hydrocarbons.
Vegetable Oils (as well as animal fats) are the primary components of Biodiesel.
Organic matter deposited in anoxic conditions has plenty of chemical potential to form hydrocarbons.
@Phillip Mulholland
Thank you for a delicious geohistory yarn. I love it when the pieces come together. The secret to good geology is to recognize the present is NOT the key to the past. It only hints at the key. History doesn’t repeat itself — but it rhymes. The fun is in identifying the crucial differences.
Just wondering , would all the coal gas and oil now underground , and left untouched , still release all their carbon dioxide etc into the atmosphere when the rock they are contained in slides down into the magma during plate tectonics ?
First I must say thank you to Anthony for publishing my essay.
Max™ @ October 6, 2013 at 10:09 am
Yes, that is the topographic map I was looking for. Thanks for the link.
grumpyoldmanuk @ October 6, 2013 at 9:53 am
Is this the sort of grumpy response you would expect?
Philip Mulholland is my legal given name. There is plenty of information about me contained in my posts on WUWT.
Dear Phillip. Thank you for a civil reply to a civil question. I did enjoy your essay, particularly the rather startling (to me at any rate) conclusion. i’ll now go through the library and read more of your work.
Regards, GOM
idreamofthought says:
October 6, 2013 at 10:58 am
“.If we continue to pump out fossil CO2 by burning carbon stored millions of years ago we will raise global temperatures … ”
Exactly what is the evidence to support your claim ?
Mr. Mulholland, thank you, now that was a very fascinating article and I see no reason to doubt the conclusion. Density trumps any temperature differences but I do wonder how just how much energy is transferred between these two layers since they are constantly being replenished each year cycle. Any insight? Would think that energy is being used by the life in the upper layer.
Absolutely fascinating. I wonder how much of the planet’s climate history is driven by how much coast line and land mass there are at given latitude.
@idreamofthought
You can dream if thinking if you like……
……but how about actually doing it for a change.
” wayne says:
October 6, 2013 at 1:33 pm
Mr. Mulholland, thank you, now that was a very fascinating article and I see no reason to doubt the conclusion. Density trumps any temperature differences but I do wonder how just how much energy is transferred between these two layers since they are constantly being replenished each year cycle. Any insight? Would think that energy is being used by the life in the upper layer.”
Well, here is a reference for water having a thermal conductivity of .58 W/(m*K):
http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html
Presumably, you could work it out from that.
Mr. Mulholland writes:
“I leave you with this conclusion. The Carboniferous was a warm ocean world, with low gas solubility in the deep sea. This produced an atmosphere suitable for land plants as they had an abundance of carbon dioxide gas to consume. Not for nothing does this period of Earth’s geological history have as its name the Carboniferous and yet in the mid-ocean above the deep abyssal anoxia, the pelagic fish also had an abundance of dissolved oxygen to breathe thanks to the presence of the Gondwana icecap and its coastal latent heat polynya.
This essay proposes that a fundamental tenet of climate science, that the world’s climate can be in one of two separate and distinct modes, either the Icehouse world or the Greenhouse world, is false.”
I admit up front that I have an axe to grind. It seems to me that Mr. Mulholland’s article reveals to all of us a science of the oceans and CO2 that the Alarmists among climate scientists could never imagine. He has given us an introduction to the complexity of the questions that must be answered if anyone is to make sense of the claim that heat is now being sequestered in the deep oceans. The big conclusion for me is that treating the deep oceans as everywhere uniform is scientific folly of the highest order. And that brings me back to a point that I have made and will make time and again. If Trenberth believes that heat is sequestered in the deep oceans then he must undertake empirical investigation of mechanisms that are peculiar to the oceans and capable of transporting (mixing, if you like) heat to the deep oceans. Unlike claims about heating the atmosphere, there is not some simple set of deductions from a theory of radiation exchanges among Earth, Sun, and manmade CO2 that can explain how the heat gets into the deep oceans.
idreamofthought
Malthus?
Please. How can one call upon cleanliness and Malthus all at once? Isn’t Malthus the real problem here? Let’s clean house and start with Malthus. Pollution of conscience.
Count_to_10 says:
October 6, 2013 at 1:39 pm
“Absolutely fascinating. I wonder how much of the planet’s climate history is driven by how much coast line and land mass there are at given latitude.”
Well said. All we get from the Alarmists is the robotic claim that climate is determined by the radiation budget among Earth, Sun, and manmade CO2 in the atmosphere. The same old, same old.
Berenyi Peter sez:
“Before I believe that story, a credible explanation should be given about the process converting organic sediments, basically carbohydrates to hydrocarbons close to thermodynamic equilibrium, which invariably occurs in buried sediment layers. That chemical process just would not happen spontaneously with no free energy input whatsoever, not even in hundreds of million years”
There’s no big mystery here. The energy needed to convert dead organic material into fluid/gaseous hydrocarbons is geothermal. Burial alone transfers ocean-bottom sediments to crustal depths where geothermal heat promotes the organic-chemical transformations. Add in the conductive heat from radioactive decay and mantle-heat transfer, along with a little magmatic activity, and there is abundant heat to transform dead plants into coal, oil, and natural gas.
Exploration geologists are keenly interested in the geothermal history of basins. Too little heat and the organic carbon remains immobile and locked in the rock. Too much heat and the basin gets “cooked” and economic hydrocarbons are driven out.
And, BTW, geologic history allows millions of years to accomplish all this hydrocarbon fractionation.
In many ways, it’s amazing that fluid hydrocarbons remain underground rather than being “exhaled” into the atmosphere. Fracking opponents take note – most rock units are extremely impermeable, meaning the infinitesimal amounts of emulsifiers and solvents that are injected during fracking (at depths generally greater than a mile) have little chance of returning to the surface.
Absolutely brilliant.
An intellectual tour de force.
For those of you who would like to know more of “Mr Mulholland” so as to judge the worth of his paper, I support you in that.
It could be said that an argument should be able to stand or fall on its merits. However, when it comes to the credibility of an opinion, the standing of the person expressing the opinion matters a great deal for most of us in terms of the vaulue we put on it.
I would make the same comment about ‘Just the Facts’ who opines at times on this blog. As he is hiding behind a non de plume I discount the credibility of his opinion, even more so than that of Phillip Mulholland who at least provides a name.
The Red Sea is a long narrow body of water with a relatively tiny discharge point at the Southern end. Its volume is approximately 55,000 cu mi. and with little input the residence time must be quite high. There is a long axial trench which is very deep and no doubt allows the more dense water to accumulate; much of the Red Sea is shallow. My understanding is that the prevailing winds for 6 to 8 months are from the southeast which pushes ocean water into the Red Sea, limiting the discharge. For this reason, the northern end has high salinity (around 41 ppt) while the southern end is more like 36 ppt (average ocean water is 35 ppt). My point is that Mr Mulholland is illustrating a known density concept with an anomalous water body that is less than 0.018% of the ocean volume. My question is what impact does this small body of water have on deep ocean temperatures and where else can this be found in the world? Seems to me that the volume of water around the Antarctic trumps any little impact of the Red Sea. Sorry, but while the concept is good, I fail to see any practical application of the Red Sea situation in the grand scheme of deep ocean temperatures.
I’d never play soccer with you. Why? Because you would like to play the man and not the ball. Attack what Mhlholland says. Show him to be wrong. That’s what matters, isn’t it.
Example, what if a homeless ex-carpenter person had written a theory that helicopter pylori caused most stomach ulcers, would you decide on that basis that he is wrong, or would you try to show him why he is wrong? Play the ball and not the man. Warmists do this when they can’t think of anything else.
heliobactor pylori…otrher than that, youre sopt on.
grumpyoldmanuk; Rab McDowell, etc says:
“For those of you who would like to know more of “Mr Mulholland” so as to judge the worth of his paper, I support you in that.”
In 1905, an unknown examiner at the patent office in Bern, Switzerland, published four articles in Annalen der Physik. This unknown writer was Albert Einstein and the four articles published in 1905 contributed significantly to the foundation of modern physics and changed views on space, time, mass, and energy. I suppose there might have been some who wanted to know just who this nobody was before wasting time evaluating what he had written on its merits.
Mr. Mulholland, thoroughly enjoyed this. Thanks.
“Dr Burns says:
October 6, 2013 at 1:27 pm
idreamofthought says:
October 6, 2013 at 10:58 am
“.If we continue to pump out fossil CO2 by burning carbon stored millions of years ago we will raise global temperatures … ”
Exactly what is the evidence to support your claim ?”
Dr. Burns
Please note, idreamofthought doesn’t claim to think –
only claim is to dream of thinking, so don’t be surprised to be presented with dreampt up evidence.
🙂
I enjoyed the article. One sentence in the article brought a question in my mind. The quote: “What his map showed is the dramatic height of this surface, both over the bulk of Greenland and also over the vast majority of Antarctica, with layers of ice piled high into the atmosphere forming a plateau as tall as the mountain ranges of other continents.”
I know from readings that ice sheets and ice caps have been and can be upwards of two miles (10,560 feet, 3219 meters) thick and snow can fall or be blown onto the summit of Mt. Everest (29,000+ feet). The more weight of the ice, the more it depresses the land underneath.
Is there a theoretical or practical limit to how high above sea level that an ice sheet, ice cap or glacier can become before the moisture carrying capacity of the atmosphere cannot overcome the sublimation of the snow and ice and it ceases to gain anymore height above sea level.
Panic over “Only web sites necessary to protect lives and property will be maintained.”
What does it actually take to maintain a web-site that’s up? Nothing! To take it down while still being paid is an act of sabotage.
@Berenyi Peter, @GeologyJim, @Stephen Rasey,
My understanding is that no biological molecule can exist at a temperature higher than the critical temperature of salt water (somewhere around 384 C). The critical temperature of salt water is reached at a depth of 3 to 5 km [1.86 to 3.12 miles], depending on whether you’re in a continental or marine environment.
http://web.archive.org/web/20111025151824/http://www.gasresources.net/Kenney-NPR.mp3
So how do you explain the creation of hydrocarbons at the depth of the crust or the mantle?
About 400MYA, the Solar System entered the Norma spiral arm of the galaxy and the ice started to form. It took about 70MY to traverse the arm, with cooling all the way. The Carboniferous ice cap peaked approx 290 MYA, about 40MY after leaving the arm. It declined rapidly over the next
20MY. Cosmic rays along the front of the Norma arm may have been pretty fierce.
The Scutum Crux arm was next at about 190MYA or about 100MY later. It generated a double
humped glaciation which doesn’t look to have been particularly strong.
There’s an interesting graphic detailing this at Nir Shaviv’s blog, sciencebits.com.
(MY = MegaYears)
LOL. Thanks. A helicopter would be quite “otrher” problem altogethreer. 😉
Is it helicobacter or heliobactor pylori?
http://www.mayoclinic.com/health/h-pylori/DS00958
http://www.medisuite.ir/medscape/a1891351-business.html#a1
policycritic sez [October 6, 2013 at 3:56 pm]
“My understanding is that no biological molecule can exist at a temperature higher than the critical temperature of salt water (somewhere around 384 C). The critical temperature of salt water is reached at a depth of 3 to 5 km [1.86 to 3.12 miles], depending on whether you’re in a continental or marine environment.”
Your question is a red herring
We’re not talking about “creation” of hydrocarbons. When organic organisms (plant/animal) die in the ocean, their remains fall to the sea floor where they get covered by sediment and the remains of countless other lifeforms. Over geologic time (millions of years), those dead organic hydrocarbons get buried to sufficient depths that they get cooked by geothermal heat. In the cooking process, long and complex carbohydrate molecules get reduced to smaller and smaller hydrocarbon molecules according to well documented organic-chemical reactions. They turn into things like propane, ethane, methane, and CO2, among others. All of this transmutation occurs inorganically, just as a result of thermal effects on formerly-living organic matter,
It’s not that complex, really
Folks
“Don’t ask a geologist what would they know anyway…” states journalist; AND backed up by a biologist:
http://www.theguardian.com/commentisfree/2013/oct/01/bbc-betrayed-values-carter-scorn-ipcc
Of course palaeoclimatology, a branch of geology, is not worth considering. After all it requires observational evidence.
They now are restructuring scientific disciplines.
” churning says:
October 6, 2013 at 2:37 pm
The Red Sea is a long narrow body of water with a relatively tiny discharge point at the Southern end. Its volume is approximately 55,000 cu mi. and with little input the residence time must be quite high. There is a long axial trench which is very deep and no doubt allows the more dense water to accumulate; much of the Red Sea is shallow. My understanding is that the prevailing winds for 6 to 8 months are from the southeast which pushes ocean water into the Red Sea, limiting the discharge. For this reason, the northern end has high salinity (around 41 ppt) while the southern end is more like 36 ppt (average ocean water is 35 ppt). My point is that Mr Mulholland is illustrating a known density concept with an anomalous water body that is less than 0.018% of the ocean volume. My question is what impact does this small body of water have on deep ocean temperatures and where else can this be found in the world? Seems to me that the volume of water around the Antarctic trumps any little impact of the Red Sea. Sorry, but while the concept is good, I fail to see any practical application of the Red Sea situation in the grand scheme of deep ocean temperatures.”
The author is using the Red Sea as an example of what mechanisms could have dominated in ages when the tropical coastline was much larger than it is now, and the arctic coastline smaller. In fact, the whole point is that the Red Sea isn’t now contributing enough to offset the Antarctic contribution.
I think one of the answers to your question about Gondwana glaciers is that they grew so large at various times that they eventually pushed the land below sea level. The ocean came in, undermined the glaciers and melted them out.
So we have repeated periods of sea level decline, then sea level increase in this time period. The Carboniferous forests of North America and Europe which were at the Equator at the time (and which were repeatedly burned down every few years by the extensive forest fires created by the very high oxygen content of the atmosphere), were then buried by the sea level increase / marine sediments and we get lots of lots of coal in North America and Europe.
This impact is rarely discussed. Continental ice sheets can get so large than the depress the continental land below sea level and eventually the ocean melts them out. Ice Sheets grow on land and they do not last very long at sea level or build up on the ocean.
Today, we have Hudson Bay, which has been pushed down by the repeated glaciation over the last 2.7 million years. It would take about 250,000 years of no glaciation for Hudson Bay to rise back up to normal, above sea level heights. The Baltic Sea, the extensive continental shelf north of Europe and Asia are also examples.
Gondwana didn’t always have glaciers. They came and left through this process, and CO2 stayed low throughout the period.
cd says:
October 6, 2013 at 4:49 pm
Paleoclimatology as practiced by climate scientists will never become part of geology.
idreaminlieuofthinking babbles: “…There were no humans cuttiing down these trees, so CO2 fell…”
Another warmist who hasn’t heard of lightning fires.
churning says: “The Red Sea is a long narrow body of water…what impact does this small body of water have on deep ocean temperatures and where else can this be found in the world?”
It’s an example showing how densities higher than ice water can exist. Just read the post: “…the key point is that Red Sea deep water produced under a modern tropical climate has a higher density at 1028.579 kg/m3 than any of the cold deep water currently produced in Antarctica by the modern world’s polar climate. “
TONGUE FIRMLY IN CHEEK – Playing the ball vs playing the man vs being a spectator: As this beer swilling spectator evaluates a metric-football (soccer) team playing the metric-ball (soccer ball) on the metric-football field (soccer field), one might take a passing interest in the metric-player who runs hither and to across the grass: hot wife like Posh Spice? previous London area teams played on (e.g. Her Majesty’s Geo Survey? BP? ENI? BP again? Statoil?)? Schools where he played metric-football before turning pro, maybe picking up some eco-greenie sounding education; however, in metric land those eco-greenie degrees might be far more rigorous than in the former colony. In any case, it is clear that the metric-football player is still quite annoyed that Her Majesty’s subject Scott was beaten to the South Pole by a descendent of those uncouth Vikings. Suppose the angst would be far worse if a Frenchy had beaten Scott to the South Pole. As it is those Frenchies invented the metric system!!! I would include the link to the presumptive LinkedIn profile to support my tongue firmly in cheek missive about this obviously skilled player, balls and the like; however, there are _REAL_ football games on the television now, not this touchy feellllllllly metric-football crap (insult against metric-football sent forth in the finest traditions of anglospheric beer drinking sports rivalry, moderated in the presence of our better halves so as to not to come to actual blows; although there might be spilled beer, burping, belching and the like). Search engine used to research the possible metric-football player? Bing of course :-):-):-)
churning ,i believe the reference to the red sea by Mr Mulholland was in relation to the situation in the period he described,and not in relation to present day.
the prevailing winds you describe do indeed create a north south density differential in the red sea,with the denser water from the north sinking below less dense water entering from the south.despite the high rate of evaporation (which creates the higher salinity ,dense water in the northern end which is taken to the deeps by the circulatory pattern) ,the net inflow during the time of prevalent wind pushing less dense ocean water into the red sea is greater than the loss through evaporation,so there is a reciprocating current,or undertow returning water back to the point of entry of the wind driven water.
the estimated time for a complete renewal of all the water in the red sea is approximately 20 years,that may be more or less than you imagined, so although it appears there is a net inflow due to narrow entry and exit routes coupled with a wind prevalent from one direction,the circulatory pattern and evaporation ensures there is a balance.if not,it would either dry up,or continually deepen.
@policycritic 3:56 pm
.. no biological molecule can exist at a temperature higher than the critical temperature of salt water (somewhere around 384 C).
We’ve .
covered this last month. There are many organic compounds that are stable at higher temperatures. Oil and gas wells all work at lower temps.
The critical temperature of salt water is reached at a depth of 3 to 5 km [1.86 to 3.12 miles], depending on whether you’re in a continental or marine environment.
Much deeper than that.
Near convergent zones and deep sedimentary basins, it is a slower gradient. It is faster near spreading zones and volcanic areas.
The deepest oil well in the US is Tiber in the deep water Gulf of Mexico at 35,055 feet, 31,000 feet below the mudline.
Mrs Dai Bread Two is looking into a crystal ball which she holds in the lap of
her dirty yellow petticoat, hard against her hard dark thighs. …
…
MRS DAI BREAD TWO : I can’t see any more. There’s great clouds blowing again.
MRS DAI BREAD ONE: Ach, the mean old clouds!
(Dylan Thomas, Under Milk Wood )
Oops! Wrong thread.
There isn’t a lot of carbon in the ‘Carboniferous’ in Australia, unlike in the northern hemisphere.
We had to wait until the Permian for abundant coal deposits. In the Carboniferous though we do have impressive glacial deposits, consistent with the vast ice sheets at the time, but little carbon. Too cold and covered in ice was Australia then I think.
During the Permian things began to change, abundant coals and warmer. And interestingly, right at the end of the Permian, widespread redbeds and a distinct ‘coal gap’ associated with the P/T mass extinction event. The organisms forming coal apparently all died out and there is no coal for about 10 million years after the mass extinction, and then the coals that formed ~10 million years later had to wait for evolution to catch up with coal formation again, and when it did, the coals are different-apparently formed from a different suite of organisms.
@Stephen Rasey
But not entirely, right? Uranus has methane in its atmosphere, and aren’t there traces of it on Jupiter and Saturn?
[Sorry, I didn’t see your August 2013 response to me, probably because I forgot the name of the thread I posted in. I don’t use the follow-up via email thing, or it would ruin my life. I do] go back and look for responses if I’ve asked a question, but sometimes I miss them.]
How can that be uniform all the way down? Temperature increases with depth. Both these wikipedia sites give different depths for the supercritical state of water: https://en.wikipedia.org/wiki/Properties_of_water and https://en.wikipedia.org/wiki/Hydrothermal_vent
I guess my point is, why aren’t the Russians right about abiotic? They’ve certainly produced enough literature about it, of which these are a few.
phe.rockefeller.edu/docs/Energy/Mendeleev/References.doc
I grew up near the Oil Sands (sort of). That stuff oozes out of the ground. It’s naturally occurring in the clear Athabasca River 200 miles upstream of Fort McMurray because it oozes out of the banks of the river. This stuff is bubbling up from deep within the earth, and some geologists up there said it was the enormous pressure of the formation of the Rockies that did it. Mother Nature’s Oil Spill. Yet, go two hours south and they point to the Devonian age Badlands and claimed (when I was a kid) that it was all fossils.
Not if CO2’s absorption bands are nearly saturated and the IPCC’s hypothesized net positive feedbacks are overestimated.
Bill James, hero of the statistical analysis of baseball, was (is?) a night watchman at a pork-and-beans factory.
Churning: The Red Sea is a weak modern stand in for the great shallow seas that were between the Appalachian Mountains and the Rockies and in other places throughout the world during this time frame. (Being an American and not a professional geologist, I didn’t look too hard at the fine details of the rest of the world – I know bad me!) There are many reconstructions of the land masses available on line if you do a little searching, and you will see on one of those recreations that the oceans (particularly the tropical oceans) were predominated by very shallow seas. When perhaps a third of the ocean surface area is on seas that have only a couple of hundred meters of depth, the situation of WARM SALTY DENSE water on the bottom of the world oceans is not just possible, but almost required.
@Stephen Rasey,
The Rockies (Jasper National Park, specifically) are the headwater for the Athabasca. This is what the lakes look like on sunny days from the calcium carbonate (CaCO3) in the water. One lake, can’t remember name, empties every year then fills up with this CaCO3 water from below. Spirit Lake (showing you because it’s so beautiful): http://i.telegraph.co.uk/multimedia/archive/02647/iStock_00001355465_2647747f.jpg
Phillip, Many thanks for a delightful geological insight (extremely well put for those of less geological background). I cannot believe I interpreted that 1974 Coal Measures field section so wrongly, attributing the Carboniferous cycles to repeated building out and then inundation of pro-grading swampy river deltas, laid down upon a progressively subsiding sea floor! Even then there was a niggling doubt in my mind as to how and why the rate of subsidence appeared to have repeatedly slowed and accelerated over so many similar cycles. Subsidence on a sticky fault plane perhaps, I wondered at the time..? But now you have a far more satisfying explanation.
And, um, RM3: where I come from, they frequently ignore the ball and the man completely, and play the spectator..
Very nice read and a compelling picture. I know you were using the Red Sea as a modern example of much larger solar-heated hot brine development in the Carboniferous that appears to have operated. However, specifically the Red Sea is an active spreading fracture that hosts considerable sea floor volcanism and hot black “smokers” issuing from fractures and depositing base and precious metal deposits on the sea floor. This is hot water indeed and I would suggest that the Red Sea may not be the perfect example of a solar-heated body of water.
This in a mining site:
“The Red Sea Alternative:
At a depth of about 2,000 meters (>6,000 feet) there are pools of mineral laden hot brines possessing enough density so that they pour like syrup, and don’t readily mix with the surrounding water. At the ocean floor below the hot brine is a thick layer of metal salts that look like a heavy black grease. It has been estimated that there is perhaps as much as $250 billion worth of metals that could be recovered from this resource not including any Black Smokers found on the seafloor nearby.”
http://mqp-geotek.blogspot.ca/2010/12/black-smokers-and-red-sea-alternative.html
Thanks for a beautifully written and informative essay. I’d never have imagined the greater importance of Antarctica in terms of oxygenating deep ocean waters. What role (if any) is played by Hudson’s Bay in global oceanic circulation?
Bill Illis says:
October 6, 2013 at 4:56 pm
“I think one of the answers to your question about Gondwana glaciers is that they grew so large at various times that they eventually pushed the land below sea level. The ocean came in, undermined the glaciers and melted them out.”
..giving the rhythmic bedding of coal and sea deposits as this mechanism seesawed back and forth. Bill, you can always be counted on to give an interesting take on things.
Great essay although the IPCC is very dense and it doesn’t trump anything.
IMO this essay is trenchant & helped me understand better the Carboniferous/Permian world, for which I am grateful to its author. However I feel that the terms “icehouse” & “hothouse” are still useful, if only as shorthand for worlds in which extensive glaciers & sea ice exist or not. I agree that they don’t necessarily imply the same suite of other global conditions.
Icehouses of various lengths do seem to occur at very roughly 150 million year intervals, for which Shaviv, et al have proposed IMO compelling if not convincing cosmoclimatological explanations.
Assessing reasons why the Jurassic/Cretaceous icehouse was so puny could be instructive.
churning says:
Starting sentences with “Sorry, but…” is more than a little paternalistic and rude – though I have done it myself. But only AFTER having read the article concerned and forming a very poor opinion of it. But “churning” here obviously left out the critical step of bothering to read the material he is ridiculing, which makes “churning” the one worthy of ridicule in this instance.
Climate “scientists” (so-called) need to get rid of every geologic & climatological eon, era, period, epoch & age before c. AD 1977 & after c. 1997 (when there was an accidental coincidence of a warming trend & rising CO2) in order to maintain their rent-seeking & ideology-driven fantasy, not just the Medieval Warm Period.
Let us not forget Thomas Gold’s hypothesis that solid and liquid hydrocarbons are produced from wee beasties chewing mineral methane…
From any long term geological perspective, the earth is now in the midsts of an Ice Age.
@ david eisenstadt says: October 6, 2013 at 3:16 pm
To the MODERATOR:
I’m so sorry, I accidentally left off the “/” in the closing blockquote on my post – so it shows up as a second embedded quote rather than showing the last line as my reply to his quote . Could you possibly add the “/” to the blockquote that appears just after “youre spot on” to make it a closing blockquote instead of an opening one? Thanks so much, I’m sorry for the hassle, and no need to post this comment of mine of course.
@ andyd says: October 6, 2013 at 3:42 pm
They’ve also shut down the Amber Alert website now too. Obama is determined to try to make this 17% reduction in federal spending as painful and as publicly visible as possible in a disgusting display of political game playing (yes, there’s only 17% of the government “shutdown”). And to do so, he’s spending more money shutting things down than it costs just to leave them open – take the open air non-monitored/patrolled national monuments for example.
We can only hope that they shut down reams of AGW related activities – but what do you want to bet those things are all still – or at least mostly – funded? Lookie there – “Realclimate.org” is still up, no shutdown there. I guess it was determined that those folks are all “essential” to “protect lives and property.” Sigh.
@Owen in GA says: October 6, 2013 at 7:28 pm
One site I ran across some time ago in this vein was the Scotese site – and it’s one of their maps used in this article. But they’ve also got a pretty good interactive map on paleogeography with animations, and if I recall correctly, discussions about what is known of the various temperatures, ocean depth/shallowness in general, and those sorts of things, for every era. They’re at: http://www.scotese.com/ and they have a pretty comprehensive site map you can find what you’re looking for or check to see what else you might be interested in also.
To go from 4000 ppm to 250 ppm is a big drop! It seems it has happened before. Would it be posible for the CO2 to go to zero – or below the level at which photosynthesis could be sustained?
CO2 is already a limiting factor for plant growth. At what point does it become not a limiting factor?
Great essay/commentary, Mr. Mulholland.
And I really don’t care how your resume reads, it’s the contents/context of your essay that matters to me.
Anyway, those who really detest and/or hate the facts that are written and referenced always want to know the name of the author/writer.
How is it possible for them to “attack the messenger” unless they know who the messenger is?
Also, I believe the proponents of CAGW need to get rid of the Cambrian Period also.
The effects of the Cambrian Period (see article’s graph) is directly contrary to the CAGW claims of death and destruction of plant and animal life if the near surface temperatures and atmospheric CO2 ppm continue to increase.
The Cambrian Period with its 5,000 to 7,000 ppm of CO2 and an average global temperature of 24 degrees C was cause for what is known as the “Cambrian Explosion”,
The Cambrian Explosion was the Period in earth’s history when like 98+% of all present day phyla, family and/or species evolved.
Evolved in climatic conditions with temperature at 24C and atmospheric CO2 at 5,000 to 7,000 ppm.
REF: http://en.wikipedia.org/wiki/Cambrian_explosion
Excellent article. Very informative.
– – – – – – –
grumpyoldmanuk,
Actually, I agree with you. It is preferable to have a complete and comprehensively integrated view of a person’s legally available public record when we are publicly discussing matters like climate science which are of high intellectual importance.
I see Philip Mulholland did disclose his given and legal identity (see his below comment). {thanks Mr. Mulholland}
grumpyoldmanuk, for the same reason, if you have not already done so in this thread, it is important to know your given and legal identity. Please be intellectually consistent and provide it forthwith
John
John Whitman@ 0747 7 Oct.
Dear John. No need to shout. 🙂 My name is Kevin Lohse and I have little scientific background, being a retired military officer. My claim to fame is staying 40 years married to a wonderful woman who is much more clever and successful than me.
” They concluded correctly that Culm was a deep ocean deposit, and although they did not recognise the true size of the ocean they were studying, we know because of their work, that the muds were bathyal sediments deposited below the carbonate compensation depth far from land. The carbon content of Culm proves that the Carboniferous world ocean was anoxic”
This is a very large leap. Without knowing the specific geology of Culm, the preservation of abyssal ocean floor is extremely rare tectonically and is probably only possible where such deposits are thrust on to continental shelves during collisions. The current compensation depth is much shallower in the Red Sea.
Excellent, provocative essay.
Phil Mulholland: Thanks for a great piece of geological arm-waving of real interest. These maps by Scotese and others show how a Red Sea-like environment may have existed on a broad scale. Somewhere I have seen Scotese’s maps with features like coal measures and glacial tills noted on the continental masses.
http://www.scotese.com/earth.htm
http://www2.nau.edu/rcb7/300moll.jpg
– – – – – – – –
grumpyoldmanuk,
Your reply is very much appreciated. Thank you. Glad to meet you.
I do appreciate it when I have some reasonable confidence in sincere discourse derived from addressing voluntarily self-identifying commenters.
Re: shouting. => usually if my comment is relatively long (like my previous comment to you) and if I have a salient point embedded it it that is not near the end of the comment, then I tend to use bold or italic for my point. Actually it helps me when others do the same in their relatively long comments. : )
I sincerely apologize if it seemed like shouting.
John
Great article, many thanks to Phillip Mulholland, there should be more articles like this here.
This is the way to address (brush aside) the speculative hypothesis of CO2 driving climate and find the true dynamics of long term climate change. Look at the history of global climate as well as geological, tectonic and biological trends, plus atmospheric CO2 and other gasses, over all timescales over the earth’s history.
Not by computer gaming with the most recent few decades of climate data.
The figure at the top of this article essentially destroys CAGW all by itself. Even more so if it were continued backward into the Cryogenian: CO2 levels rocket skywards, temperatures fall into the Marinoan and Sturtian ice ages.
@policycritic 10/7 7:15 pm
Methane is an organic compound. It is likely the first compound you study in Organic Chemistry.
That does not mean that it cannot be created by inorganic processes – it is found in hydrogen rich planetary atmospheres: CO2 + 4 H2 == CH4 + 2 H20 (exothermic at 164.9 KJ/mol). That is why you can find CH4 on the outer planets with out the requirement that they have life. Their gravity is sufficient to retain Hydrogen.
Titan is more of a mystery because it has CH4, but ultraviolet light should have destroyed it long ago through 2 CH4 + UV = C2H6 + H2 (escapes to space). This is an example of inorganic formation of short carbon chain molecules from hydrogen starvation in a reducing environment. Who knows?…. Maybe it is an indication that Titan does harbor life. 😉
What bearing does this have on the Russian abiotic claims for the formation of hydrocarbons? Earth is a hydrogen poor, oxygen rich planet. What hydrogen we have is locked up in water and hydrocarbons and other organic compounds. Carbon-hydrogen compounds in the presence of O2 and absence of H2 will tend toward CO2 and H20, not the reverse.
Even if the Russian authors are right that hydrocarbons CAN be formed at mantle conditions, it does NOT INVALIDATE the theory most of our oil and gas hydrocarbons are formed by the thermal cracking of organic material in sedimentary rocks. It is amazing what you can learn about the source rocks of oils using a gas chromatograph.
If we didn’t know oil sources after decades of geology, the fracking of shale oil proves a sedimentary origin of oil. Shale oil formations are so impermiable, we must shatter them by frac’ing to get the oil out. So how can that oil possibly migrate from somewhere else, much less from the mantle, into a rock consided otherwise to be a good reservoir seal?
Good post. I hope that you can get it published.
“Sridhar Anandakrishnan, Professor of Geosciences, at Penn State is reported as saying:-Eventually, with all that atmospheric heat, the oceans will heat up.”
I am repeatedly struck by the things the CO2 believers say that ignore the actual mechanics of heat transfer in the environment and the inaccuracies of the equilibrium approximation that drives the alarmist warmism. Based on what is known about heat transfer within the climate system, that is not necessarily true. Within the inaccuracy limits of the equilibrium approximation, the entire predicted temperature increase could occur in the upper troposphere with no increase in the total lower level and surface heat content.
Caveat: the “report” might not be true.
@policycritic 10/7 7:15 pm (more)
SR:Away from tectonic plate boundaries, [the average Geothermal Gradient] is about 25°C per km of depth.
PC:How can that be uniform all the way down? Temperature increases with depth.
The geothermal gradient specifies how quickly the temperature increases with depth. The average gradient on the continental crust is 25°C per km. In the Mississippi Delta, it can be lower, such at 18°C.
critical temperature of salt water (somewhere around 384 C). The critical temperature of salt water is reached at a depth of 3 to 5 km.
Even if we use your 5 km deeper depth, that would indicate a geothermal gradient of about 370°C in 5 km or 74°C/km. That kind of geothermal gradient is found only around hot springs and volcanic areas; areas that are not known for oil and gas potential. Here is a map and chart of geothermal gradients.
@policycritic 10/7 7:15 pm (more)
I grew up near the Oil Sands (sort of). That stuff oozes out of the ground. It’s naturally occurring in the clear Athabasca River 200 miles upstream of Fort McMurray because it oozes out of the banks of the river. This stuff is bubbling up from deep within the earth, and some geologists up there said it was the enormous pressure of the formation of the Rockies that did it.
Yes. But the question is “how deep”? It is not the mantle. It is 4 to 8 km. Here is a good cross section of the foreland basin, migration and entrapment of the Athabasca oils. According to this, most of the oil comes from the deep water anoxic Devonian shales. The Cretaceous seaway eroded down to the Devonian as a subcrop and then, perhaps in the late cretaceous and start of the Canadian Rockies laid a quartz sand on it. Further mountain building through to the Eocene by thrusting from the west depressed the Devonian, gradually raising the Devonian shale’s temperature and pressure, cooking the organic matter converting to oil which then migrated updip into the subcropped Cretaceous sands.
Much of what passes for ‘climate science’ involves verbal explication of presumed mechanisms.The weakness of this kind of argument is that it is biased towards positive feedback mechanisms: More A causes more B, more B causes more A, and it is a positive feedback that leads to ‘tipping points’ and ‘runaway’ effects.
Thermodynamics and nature conspire against such circumstances in favor of negative feedback mechanisms such as those discussed by Mr. Mulholland.
Positive feedback mechanisms reflect instability, and the systems in which they occur inevitably collapse. If the earth’s temperature had a positive feedback mechanism, it would have long since tipped to the extreme – it his had billions of years to become either an ice world or a greenhouse world, with no mechanism proposed for it to not stay that way.
The fact that it has not become either indicates there is a very powerful negative feedback mechanism that the climate scientists have not yet modelled. Verbal explications cannot account for this.
Bottom line to the climate scientists: Show us the measurements or STFU.
An anoxic deep ocean layer is a bold and thought-provoking scenario. During the periods with the earth in the hothouse attractor, was the deepest ocean in fact anoxic?
Lets assume it was. It would not be as catastrophic as one might at first think. Yes, major extinctions such as the Permian/Triassic involved oceanic anoxia maybe all the way up to the surface. However today’s Black Sea is a reasonably healthy ocean despite its sulphurous anoxic depths after which it is named.
But extrapolate that to most of the worlds ocean basins and we have to deal with the phenomenon of anoxic upwelling, and what it would mean. In today’s oceans, the best known upwelling phenomenon is the Peruvian coast upwelling. This brings life-giving nutrient rich deep cold water to the surface fuelling the gigantic anchovy fishery off Peru and upwelling is responsible for the amazingly fecund biota of both South America’s and Africa’s west coasts. The colossal Antarctic upwelling described in Mulholland’s article sustains the enormous krill and other zooplankton populations of the southern ocean.
But upwelling would also have taken place in a hothouse attractor world with an anoxic deep ocean. Instead of life-giving nutrient re-supply to the surface, it would have been a baleful hand of death from below, erupting anoxia to the surface and causing major kills of fish and other marine life.
In large, the implication of abyssal anoxia is that the hothouse attractor world would have substantially less global ocean productivity than the coolhouse attractor in which ocean bottom water is aerated and energised by the thermohaline circulation driven be downwelling of cold, oxygenated polar water.
Thus the cooling Cenozoic would be characterised by strongly increasing global marine productivity and biomass as the surge in aerated cold downwelling brought oxygen to the ocean depths.
One legacy of this process is clear. We are priviledged to share the planet with the largest, most magnificent creatures ever to have lived on earth, the whales. These splendid gentle giants were drawn by inexorable evolution from the plains of Africa and India by the call of billions of fat krill in the southern seas. These are the children of the Cenozoic, the progeny of the cold downwelling of lifegiving oxygenated water to the depths of the worlds oceans. So the coldhouse attractor may be more barren on land but is much more fecund at sea.
phlogiston says:
October 7, 2013 at 12:10 pm
Well stated & reasoned. Thanks.
As previously noted on this blog, one of the animal species with a greater biomass than humanity is the Antarctic krill Euphausia superba.
The massive P/T Mother of All Extinction Events is associated not just with oceanic anoxia, but also euxinia (hydrogen sulfide abundance).
Earth’s atmospheric concentrations of carbon dioxide have been depleted from upwards of 100 Earth atmospheres composed of more than 96 percent carbon dioxide or more than 960,000 ppm of carbon dioxide to less than 300 ppm in one Earth atmosphere. So, where did all of that vast amount of carbon dioxide go to? Answer: a variety of processes removed the carbon dioxide from the Earth’s atmosphere ranging from geochemical processes to plant life eating the carbon dioxide. About 2,200 million years ago anaerobic lifeforms gave rise to aerobic lifeforms that consumed the carbon dioxide out of the atmosphere and released emissions of oxygen formerly bound up in the carbon dioxide molecules. Previously, Oxygen was only a trace gas in the Earth’s atmosphere, and what little was released into the atmosphere immediately oxidized with the iron and other reactive materials in the environment. Aerobic lifeforms, however, released such vast amounts of oxygen as they consumed nearly 100 Earth atmospheres of carbon dioxide, the iron lying around in the regolith and seas became oxidized as Iron oxide, and other oxide compounds such as Sulfur dioxide. Once these readily available supplies of oxidation materials were exhausted, concentrations of Oxygen began to build-up in the atmosphere of the Earth and in the seas. The availability of atmospheric and marine oxygen facilitated the development of more complex marine and terrestrial lifeforms. The Plant Kingdom pretty well removed nearly all of the carbon dioxide from the Earth’s atmosphere, until only trace amounts of the gas remained. And, so it is today.
Carbon dioxide is being replenished in the Earth’s atmosphere by a variety of processes ranging from geochemical processes to biochemical processes and combustion. All forms of oxidation of a carbon compound results in a release of carbon dioxide. So long as there are forest fires, prairie fires, rotting organic matter, and asteroid and cometary impacts, there will continue to be emissions of carbon dioxide into the atmosphere; and so long as there is plant life around to eat the carbon dioxide out of the atmosphere, carbon dioxide will remain depleted to the minimum levels needed to sustain the plant life.
Human emissions of Carbon dioxide are so low in comparison to natural sources of Carbon dioxide emissions, current methods of measuring the Human emissions are difficult to measure with any accuracy. Simply put, Human emissions are dwarfed in comparison to natural sources of Carbon dioxide emissions. The slightest change in a natural source of Carbon dioxide emissions can therefore be far more influential than all of the Human emissions since the advent of the Industrial Age. To gain some idea of what is involved you have to compare all of the human sources of combustion and cement production to all of the Earth’s natural sources of oxidation of Carbon compounds. Imagine what that entails.
Interesting article. Nice that someone else is bringing up Antarctica’s katabatic winds as a significant factor in global climate. Also, rare recognition of interactions among all of geography’s “spheres” – atmosphere, hydrosphere, cryosphere, lithosphere, biosphere.
D. Patterson says:
The Plant Kingdom pretty well removed nearly all of the carbon dioxide from the Earth’s atmosphere, until only trace amounts of the gas remained. And, so it is today.
==============================================================
The animal kingdom helped it all along, too. The foraminifera (et al)
in the oceans build carbonate shells/frame-works which are deposited
on the sea bed. Each tiny shell/framework takes some CO2 out of circulation.
The deposits are eventually raised as limestones and chalks. You don’t
need to look far to see just where that 4000 ppm of CO2 Mega Years ago
disappeared to …
We make cement out of some of those deposits. And concrete out of the
cement.
Thank you to all who posted replies, both for the kind comments of support and also for the technical challenges, particularly those addressing the geological substance of my essay.
Only have time at the moment to reply to one:-
gymnosperm October 7, 2013 at 7:57 am
An important paper on the Carboniferous Culm of south-west England was published in 1895. This is a short extract from the conclusions (p662):-
G. J. Hinde, and H. Fox. 1895 On a Well-Marked Horizon of Radiolarian Rocks in the Lower Culm Measures of Devon, Cornwall and West Somerset.
Quarterly Journal of the Geological Society, Vol 51, p609-668.
Hi Phillip,
I learned something today. Thanks for making the Carboniferous come alive again.
Julian in Wales says:
October 7, 2013 at 2:53 am
C4 plants like corn (maize) & sugar cane can still conduct photosynthesis at CO2 concentrations as low as ten ppm. The much more common C3 plants, including trees & most other crops, start starving at about 150 ppm. When CO2 level in their chloroplasts drops below 100 to 50 ppm, the catalyst rubisco which helps fix carbon starts fixing oxygen instead.
But C3, C4 & CAM plants all benefit from higher CO2 concentrations, up to at least 700 or 800 ppm.
PS: Actual greenhouses keep CO2 at 1000 ppm or more, but some people start getting head aches at that level.
@D. Patterson 10/7 12:42 pm
Earth’s atmospheric concentrations of carbon dioxide have been depleted from upwards of 100 Earth atmospheres composed of more than 96 percent carbon dioxide or more than 960,000 ppm of carbon dioxide to less than 300 ppm in one Earth atmosphere.
What evidence/links do you have for a 100 bar early Earth atmosphere? No criticism, because it agrees with my view of the world’s history. (See July 11, 2013 at 1:01 pm in “… Faint Young Sun Paradox…”
Far too many times people refer to figures like “4000 ppm CO2” paleo atmospheres without bothering to consider 4000 ppm of a 10 bar atmosphere is far different than 4000 ppm of a 1 bar atmosphere. There is no reason to believe atmospheric pressures have remained constant for 3 billion years. So estimates Total Partial Pressures of CO2 is probably more informative than ppm estimates.
I know of no evidence for high Archean atmospheric pressures. Unfortunately Gary Hladik July 10, 12:14 pm found some to the contrary:
In my 1:01 pm comment, I pointed out some potential holes in their analysis, but it was mostly because I didn’t like their result. As a fall back, I was reduced to:
So if you have something to support a higher atmospheric pressure to counter Som’s explanation of fossilized raindrops I’m eager to learn it.
Regarding Trenberth and heat getting to the deep ocean, as pointed out here, Antarctic Bottom Water (AABW) is created around Antarctica, descends to the deep because it is dense, and then drives a lot of deep water circulation. We see evidence of its scouring action in many places, for example off the continental margin of southern Africa. A similar process produces Arctic Bottom Water (ABW). In both cases, if the process continues but with surface waters in the production zone being slightly higher (but not high enough to stop the process), it is conceivable that more heat would be transported to the deep. For example, AABW descends to the deep as normal but at a slightly higher temperature. However, if measured properly, the slightly higher surface temperature required should also raise the average surface temperature of the oceans too. Are there ARGO buoys deployed in the region of bottom water production? The point is that, considering how deep thermohaline convection currents are produced, it is difficult to see more heat reaching the deep ocean without first being noted in the surface ocean.
Stephen Rasey says:
October 7, 2013 at 10:52 pm
There is no need to posit 5-20 bar in the Mesozoic Era to support powered flight by the largest pterosaurs. Oxygen may however have been more abundant (25-30% as opposed to today’s 21%) in the Jurassic & Cretaceous Periods, facilitating the evolution of powered flight in birds. Pterosaurs evolved in the Late Triassic, however, with O2 levels similar to or lower than now.
IMO it would be hard to explain how atmospheric pressure could have been 5-20 times higher than now during the Cretaceous, when the largest pterosaurs lived. Where did all that extra nitrogen (now 78% of air) &/or argon (less than 1%) go? While CO2 was much higher than now, it was still a trace gas. Perhaps surprisingly, the warm, equable Late Cretaceous may have averaged only about 1.4 times today’s water vapor in its air. There may have been more methane, thanks to giant sauropod flatulence & other biological activity, but still not enough to thicken the air significantly.
Assume for sake of discussion that the O2 level was 30%, or nine percentage points higher than now. Assume further that an approximately equal amount of N2 combined with O2 in various forms during the catastrophic atmosphere of the Cretaceous-Tertiary extinction event & somehow permanently left the air. This is likely to overestimate the amount of N2 lost, since both NO & NO2 would have been formed, & the O2 level might have been less than 30%. Thus Late Cretaceous atmospheric pressure might have been at most 18% higher than now, given this view of its two most important constituent gases. Throw in higher levels of trace gases, & call it 20%, tops, IMO.
The supposition that the biggest pterosaurs needed much thicker air to fly rested on estimates of their weight & strength now considered wrong. Some researchers thought they couldn’t fly at all. Recent anatomical estimates & biomechanical studies suggest that they could launch themselves into the air, flap for a while, then soar long distances rapidly. They would however have benefited from higher oxygen concentration during the leaping & active flying phases.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0013982
They could probably still fly in today’s relatively oxygen-poor & possibly slightly less dense air.
@ D. Patterson says:
October 7, 2013 at 12:42 pm
Very informative answer – I learnt a lot
“Carbon dioxide is being replenished in the Earth’s atmosphere by a variety of processes ranging from geochemical processes to biochemical processes and combustion. All forms of oxidation of a carbon compound results in a release of carbon dioxide. So long as there are forest fires, prairie fires, rotting organic matter, and asteroid and cometary impacts, there will continue to be emissions of carbon dioxide into the atmosphere; and so long as there is plant life around to eat the carbon dioxide out of the atmosphere, carbon dioxide will remain depleted to the minimum levels needed to sustain the plant life.”
It was suggested that Ice ages suck CO2 out of the biosphere – is that true? Perhaps by altering the balance of the carbon cycles?
@ milodonharlani says:
October 7, 2013 at 8:53 pm
So if the level drops to below about 150 there would be mass extinctions? Obviously this will not happen anytime soon, but is it possible?
@ D. Patterson says:
October 7, 2013 at 12:42 pm
– – – – – – –
D. Patterson,
Your discussion on the orders of magnitude of sources and sinks of atmospheric CO2 was well done.
It puts the fossil fuel burning source in reasonable perspective, an unalarming one.
Salby’s presentations on sources and sinks were reasonable too.
John
Regarding methane from non-organic sources, the Beatrix deep level gold mine in South Africa has large emissions which have caused explosions in the past. They are even considering using it to generate electricity. The interesting thing is that these rocks are PreCambrian conglomerates that rest on ‘basement’, so the methane is unlikely to come from anywhere other than at depth. There is also methane emissions recorded from South African platinum mines which are hosted in ultramafic intrusive rocks, again PreCambrian, with their origin from the mantle.
tadchem says:
October 7, 2013 at 11:59 am
“Much of what passes for ‘climate science’ involves verbal explication of presumed mechanisms. The weakness of this kind of argument is that it is biased towards positive feedback mechanisms.”
Right you are. And said bias toward positive feedback mechanisms is a prerequisite of/for the climate scientists and others that have a vested interest in touting their claims about the dire effects that will result via any increases in CO2 causing AGW.
In my learned opinion, the claims being touted about positive and negative feedback mechanisms associated with thermal energy transfers within the earth’s atmosphere are as disingenuous as the claims about “greenhouse” gases existing in the earth’s atmosphere.
The use of the words ….. positive, negative and greenhouse … serves no purpose whatsoever other than to influence and/or bias the public’s belief and opinion in favor of the “junk science” claims associated with CAGW.
To claim “positive feedback” verses “negative feedback” is to infer “fault” of a specific entity wherein “no fault” exists. The positive and negative “feedback” associated with a “bar” magnet is not a dastardly “fault” of its magnetic flux.
There is no such thing as a “greenhouse” gas in either the confines of an actual green house or in the earth’s atmosphere. Now if one wants to claim or infer there is a “greenhouse” effect to explain the results of thermal energy transfers within or out of a system, then fine by me.
What a fascinating read. Thanks Mr. Mulholland.
An interesting piece to the methane puzzle is the tally (which is of course debatable) that there is way too much of it to have been produced by all the biomass that ever lived on earth.
Julian in Wales says:
October 8, 2013 at 2:37 am
A drop to 150 ppm (Earth gets close during the depths of ice age glacial phases, down to 190 ppm or lower) would at the very least stress life. As C3 plants & the microbes, animals & fungi dependent upon them struggled, C4 & CAM plants might expand to take up some of the slack.
At 50 ppm, all C3 plants would perish.
Thanks Milodonharlani – you answered my questions
milodonharlani says:
October 8, 2013 at 12:05 am
Stephen Rasey says:
October 7, 2013 at 10:52 pm
There is no need to posit 5-20 bar in the Mesozoic Era to support powered flight by the largest pterosaurs. Oxygen may however have been more abundant (25-30% as opposed to today’s 21%) in the Jurassic & Cretaceous Periods, facilitating the evolution of powered flight in birds. Pterosaurs evolved in the Late Triassic, however, with O2 levels similar to or lower than now.
I agree. With the dinosaurs and pterosaurs its important also to remember that they have the same lung physiology / anatomy as birds. This is very different to the mammalian one. Essentialy, air travels only one way through the avian / dinosaur lung, due to a rather complex anatomy of air tubes and sacs extending into bones and other spaces in the animal. This is hugely – well about 10 times – more efficient than our tidal lungs where air comes in and goes out the same way. In our tidal breathing the O2 concentration drops to its minimum at the terminal alveolar sacs – just where it is most needed. By contrast air passing the avian / dinosaur alveoli has O2 at full atmospheric pressure.
This allows dinosaurs including birds to have smaller, rigid lungs which achieve much more efficient gas exchange. Thus the dinosaur / avian rib cage extends all the way to the end of the torso – no soft belly with a 6 pack. This is the reason why both birds and pterosaurs can fly, and why the dinosaurs ran rings around mammals for 150 million years.
So it is not necessary to give dinosaurs or pterosaurs a special handicap such as fictitious atmospheres to explain their obvious lifestyles e.g. flying of pterosaurs. They could do so I am sure even in the current atmosphere.
Thanks BTW for your response to my stream of consciousness about deep water currents and whales.
@milodonharlani at 12:05 am
There is no need to posit 5-20 bar in the Mesozoic Era to support powered flight by the largest pterosaurs. Oxygen may however have been more abundant (25-30% as opposed to today’s 21%) in the Jurassic & Cretaceous Periods, facilitating the evolution of powered flight in birds. Pterosaurs evolved in the Late Triassic, however, with O2 levels similar to or lower than now…
The supposition that the biggest pterosaurs needed much thicker air to fly rested on estimates of their weight & strength now considered wrong. Some researchers thought they couldn’t fly at all.
There are some circular arguments here. If some researchers thought they couldn’t fly at all, it argues for different atmospheric conditions than the researchers posit.
If Pterosaurs “evolved” in the Late Triassic, with “lower O2 levels” [in ppm or partial pressure?], then what ecological niche did they evolutionary fill? There must be some advantage in there size or they couldn’t survive in enough abundance to create fossils we’d find.
estimates of their weight & strength now considered wrong.
Says who?
There is an aerodynamics proposition that the power needed to stay aloft is inversely proportional to (air density)^0.5. (see “So Dinosaurs Could Fly, Part I” Jun 2, 2012 9:31pm
Bigger flying creatures prefer denser atmospheres. It is that simple. Evolution likes to fill niches where it can. We have fossil evidence that life filled niches in the past 400 MYa that don’t exist today.
Here is an article from Levenspier, Fitzgerald, and Pettit (2000) Earth’s atmosphere before the age of dinosaurs which discusses several questions about the amount of limestone and the size of fauna that point to higher atmospheric pressures in the past. I don’t accept some of their arguments, particularly the “Limestone Caves” chemical balance. Also accumulation of coal beds in the Carboniferous pointing to low oxidation rates, and therefore low O2 concentrations runs counter to the large insects like Meganeura of the time. But they are correct to point out that the large volume of Carbonates deposited over the past 500 MYa must point to much higher CO2 partial pressures. And with high CO2 partial pressures, don’t we need higher O2 partial pressures for animal life to survive.
An area-domain cross-plot of CO2 vs O2 partial pressures with domains for where animal life is possible, where forests fires are all consuming, where coals can accumulate from decaying plant life, where C3 and C4 plants thrive and die, would be an interesting graphic.
milodonharlani says:
October 8, 2013 at 8:57 am
Julian in Wales says:
October 8, 2013 at 2:37 am
A drop to 150 ppm (Earth gets close during the depths of ice age glacial phases, down to 190 ppm or lower) would at the very least stress life. As C3 plants & the microbes, animals & fungi dependent upon them struggled, C4 & CAM plants might expand to take up some of the slack.
At 50 ppm, all C3 plants would perish.
On that topic, this paper by Franck et al. is informative. In it the reason for final biosphere extinction is given as CO2 starvation.
http://www.biogeosciences.net/3/85/2006/bg-3-85-2006.pdf
@phlogiston 9:25 am
Ok. Birds have the same physiology as pterosaurs ( a hypothesis ). Hopefully in 100 MY of evolution birds have made some physiological improvements on pterosaurs.
So… where are the birds who are as big as were the pterosaurs?
Where today are the dragonflies with 26 inch wing spans?
phlogiston says:
October 8, 2013 at 9:29 am
Thanks for that link. Not all C3 plants will immediately die out at 150 ppm, but will cease flourishing. By 100 ppm most will have died & all by 50 ppm.
Julian in Wales, October 8, 2013 at 2:37 am
Studies of the fossil flora at Rancho La Brea Tar Pits in California suggest that during the depths of the last ice age, the land plants were suffering from CO2 deprivation.
Stephen Rasey says:
October 8, 2013 at 9:27 am
“There are some circular arguments here. If some researchers thought they couldn’t fly at all, it argues for different atmospheric conditions than the researchers posit.”
Those who thought they couldn’t fly did so based upon their faulty estimates of body weight & strength, not upon air pressure. What is circular is to make bad guesses about weight, then to infer from those that to have flown, they needed denser air.
“If Pterosaurs “evolved” in the Late Triassic, with “lower O2 levels” [in ppm or partial pressure?], then what ecological niche did they evolutionary fill? There must be some advantage in there size or they couldn’t survive in enough abundance to create fossils we’d find.”
Percentage of the air occupied by volume, ie ~20% instead of ~30% O2, so parts per hundred, not per million.
When pterosaurs developed, the niche of volant vertebrate did not yet exist. They were the first to fill it, apparently first by gliding to catch insects. They became giant only after tens of millions of years. They started out small bird-sized in the Triassic. Why would you put “evolved” in quotes? That’s what they did.
When in the Jurassic & especially the Cretaceous pterosaurs became big, bigger & biggest, increasing size did naturally confer selective advantages in new niches, such as skim-fishing over inland seaways. One way paleontologists know they flew is that their remains are often found in marine sediments. They didn’t paddle out there. Science also finds remains of the same species on both sides of the Atlantic, then admittedly much narrower than now.
“estimates of their weight & strength now considered wrong.
Says who?”
Please read the link I posted. It has been considered pretty despositive by most researchers.
“There is an aerodynamics proposition that the power needed to stay aloft is inversely proportional to (air density)^0.5. (see “So Dinosaurs Could Fly, Part I” Jun 2, 2012 9:31pm”
http://web.mit.edu/16.unified/www/SPRING/systems/Lab_Notes/airpower.pdf
Eq. 17 shows that the Power = Energy/time, is inversely proportional to sqrt(density), and proportional to weight^(3/2)
Can we assume that Max Power from an organism is no better than proportional to weight? Pmax proportional to W^(x) where 0 < x <= 1.
I conclude that the max weight of a flying organism is proportional to AirDensity^(1/(3-2x))
If x = 1, then Max weight is proportion to air density.
If x = 0.8, then Max weight is proportional to AirDensity^(0.71)
Bigger flying creatures prefer denser atmospheres. It is that simple. Evolution likes to fill niches where it can. We have fossil evidence that life filled niches in the past 400 MYa that don’t exist today.
Here is an article from Levenspier, Fitzgerald, and Pettit (2000) Earth’s atmosphere before the age of dinosaurs which discusses several questions about the amount of limestone and the size of fauna that point to higher atmospheric pressures in the past. I don’t accept some of their arguments, particularly the “Limestone Caves” chemical balance. Also accumulation of coal beds in the Carboniferous pointing to low oxidation rates, and therefore low O2 concentrations runs counter to the large insects like Meganeura of the time. But they are correct to point out that the large volume of Carbonates deposited over the past 500 MYa must point to much higher CO2 partial pressures. And with high CO2 partial pressures, don’t we need higher O2 partial pressures for animal life to survive.
An area-domain cross-plot of CO2 vs O2 partial pressures with domains for where animal life is possible, where forests fires are all consuming, where coals can accumulate from decaying plant life, where C3 and C4 plants thrive and die, would be an interesting graphic."
Nobody disputes that CO2 was much higher than now for most of the Phanerozoic Eon. Giant Carboniferous dragonflies show that oxygen content was also dangerously high then, at around 35%, producing frequent wild fires.
But that doesn't imply that Mesozoic air pressure was 5 to 20 bar. Again I ask, to where did that titanic amount of N2 suddenly disappear in the Cenozoic?
Stephen Rasey says:
October 8, 2013 at 1:59 pm
“@phlogiston 9:25 am
Ok. Birds have the same physiology as pterosaurs ( a hypothesis ). Hopefully in 100 MY of evolution birds have made some physiological improvements on pterosaurs.
So… where are the birds who are as big as were the pterosaurs?
Where today are the dragonflies with 26 inch wing spans?”
Birds, other dinosaurs & pterosaurs had similar breathing physiology. That doesn’t mean that the rest of their anatomies were similar. In some ways, pterosaurs more resemble bats, although not in O2 delivery system. Some faulty estimates of their weight & strength were based upon avian analogies that have been shown invalid.
There have been some very big birds in the past, including flying species, although not like the largest pterosaurs. Birds got big & stayed that way for a long time after the other dinosaurs & pterosaurs disappeared. Most pterosaurs, including all the little ones, had already gone extinct by the Maastrichtian, the last age of the Cretaceous, while birds had flourished.
The teratorns & other large volant birds existed fairly recently, ie in the Pliocene to Pleistocene. Some may have lingered long enough into the Holocene to inspire American Indian thunderbird legends, although I don’t find that suggestion too convincing. They achieved up to seven meter wingspans, versus the 10 to 15 m of the azhdarchid pterosaurs:
http://en.wikipedia.org/wiki/Argentavis
Dragonflies were huge in the Carboniferous Period (not the Mesozoic Era) more because of high oxygen content than total air P much denser than now. Pressure was higher then, but not five to 20 bar.
milodonharlani says:
October 8, 2013 at 8:57 am
….At 50 ppm, all C3 plants would perish.
>>>>>>>>>>>>>>
Originally I had a link showing 200 ppm was the lower limit. Then the Ice Cores started showing 180 ppm so the lower limit was then 180 ppm.
These are C#3 and not C4 or CAM which can deal with lower levels of CO2.
Where did you get 50 ppm from?
Gail Combs says:
October 8, 2013 at 2:57 pm
I know that trees are C3 plants, but there is a difference, as noted, between the point at which a plant starts suffering CO2 starvation & where it can no longer conduct photosynthesis at all. Humans for instance can survive on starvation diets for a long time before dying.
A plant’s CO2 compensation point is the level at which net photosynthesis stops. In the lab, this has been measured at between 50 & 100 ppm, depending upon the C3 species being investigated:
http://www.ncbi.nlm.nih.gov/pubmed/11607591
Obviously, in the wild, C3 plants will suffer between 100 & 150 ppm without necessarily perishing immediately.
Stephen Rasey says:
October 8, 2013 at 1:59 pm
@phlogiston 9:25 am
Ok. Birds have the same physiology as pterosaurs ( a hypothesis ). Hopefully in 100 MY of evolution birds have made some physiological improvements on pterosaurs.
So… where are the birds who are as big as were the pterosaurs?
Where today are the dragonflies with 26 inch wing spans?
OK I accept there might have been higher [O2] in the past especially to explain those big insects. How high does [O2] have to get in the atmosphere before a single flash of lightning will burn down any vegetation that is not currently being rained on?
milodonharlani 2:34 pm
The teratorns & other large volant birds existed fairly recently, ie in the Pliocene to Pleistocene. …. They achieved up to seven meter wingspans, versus the 10 to 15 m of the azhdarchid pterosaurs: http://en.wikipedia.org/wiki/Argentavis
Dragonflies were huge in the Carboniferous Period (not the Mesozoic Era) more because of high oxygen content than total air P much denser than now. Pressure was higher then, but not five to 20 bar.
Ok, now we are getting somewhere.
You agree the pressure was higher in the Carboniferous. I don’t know if it was as high as 20 atm (the upper end of my range). 5 atm might be high for a low side. I can come down to 3 atm.
2 atm is a bit hard to do. Here’s why:
The biggest birds today are somewhere between 1/2 to 1/3 the DIMENSION of the biggest pterosaurs. Mass goes with Dimension as the cube. Let’s say that the biggest Condors are only 1/2 of size of the pterosaurs. That means the pterosaurs were at least 8 times the weight, and maybe not as flight efficient as a condor. So go back to Eq. 17. 8 times the weight is hard to do without at least 8 times the density of air. Even if somehow the pterosaur somehow scales by area and not volume, it must still be 4 times the density. Split the difference and you are at 6. These are conservative estimates, starting from the observation/hypothesis that today’s bird’s wingspans are as big as 1/2 of the pterosaurs.
Go back to that 26 inch dragonfly in the Carboniferous.. You can’t get there just by more oxygen partial pressure. 26 inches is 5 times today’s biggest dragon fly. Scale it up not by volume ( power of 3) but by the power of 2.5. It is over 50 times heavier than today’s bug. How can you do that without about 50 times denser atmosphere? The only way I see it is you don’t just raise the partial pressure of O2 from 0.21 bar to 0.3 bar, but raise it to 1.0 bar which potentially gives an organism of 5 times the power potential for equal weight. Therefore you could get such a dragon fly with a 10 bar atmosphere with 10% oxygen, 1.0 bar O2.
Stephen Rasey says:
October 8, 2013 at 3:55 pm
We’re not getting anywhere. We’re right back where we were.
It’s hard even to get to two bar as the Carboniferous maximum air pressure, let alone three or five to twenty. I keep asking where you think all the N2 went, then as now the major component of earth’s atmosphere, & you keep not answering.
Studies of the Carboniferous atmosphere find falling CO2, taken up by plants, while O2 increased. The lack of fungi contributed to the formation of coal swamps.
The spontaneous-combustion-set upper limit on O2, around 35%, may well have been reached during the Carboniferous. However scientists researching the Period have found no evidence for a doubling, tripling or 20-fold increase in N2:
http://jeb.biologists.org/content/201/8/1043.full.pdf
“Concomitant with this reduction in carbon dioxide
concentration, the oxygen concentration of the late Paleozoic
atmosphere may have risen to as high as 35 % (Berner and
Canfield, 1989; see Fig. 1), a remarkable value compared with
the 20.9 % of the contemporary atmosphere. This elevation of
oxygen partial pressure occurred against the background of a
constant nitrogen partial pressure (Hart, 1978; Holland, 1984),
yielding an increased total pressure of the atmosphere.”
Now, that constant N2 may have been somewhat higher than now, but not enough even in combo with fifteen percentage points higher O2 concentration & trace gases, even to double total air P.
So even making the generous assumption that N2 increased as much as O2, for which there is no evidence, we’re talking 1.3 bar, not 2.0, 3.0, 5.0 or 20.
The high O2 helped flight metabolism & the slightly denser air made flying a bit easier, but that’ it. So we’ve gotten nowhere.
The best physical evidence now available suggests at most two bar in the distant past, ~2.7 Ba, with decline to near present density before the Paleozoic Era 543 Ma. The constituent components change within narrow ranges, with high CO2 in the Cambrian Period replaced by even higher O2 by the Carboniferous, but overall atmospheric surface pressure hasn’t altered all that much.
As noted, for instance, oxygen fell down to around 15% in the Early Triassic, after the End Permian Mass Extinction Event, then rose during that Period in which the first small pterosaurs evolved, & continued doing so in the Jurassic, when birds developed. But I’m repeating myself, although with more numbers.
phlogiston says:
October 8, 2013 at 3:38 pm
As above, 35% O2 concentration makes fires easy to start & hard to stop. So the giant Carboniferous dragonflies probably enjoyed oxygen levels a little lower than that, but higher than present 21%.
milodonharlani says: @ October 8, 2013 at 3:08 pm
>>>>>>>>>>>>>
Thanks
It does get a bit murky. I think there is also another point below which plants do not have enough energy to reproduce. Perhaps that was the 180 to 200 ppm. Also it probably differs from species to species a bit. (I am a chemist not a biologist BTW)
It’s not straight-forward since CO2 can’t be taken in isolation, but other factors such as temperature, water, sunlight, elevation, growing season, total air pressure, etc. naturally also figure into overall growth & plant health:
http://www.ncbi.nlm.nih.gov/pubmed/19017126
It’s safe to say that under glacial conditions, 150 ppm is starvation for most C3 plants. As you note, the plant itself could survive just barely, but not have enough energy or resources to reproduce, like yard plants when I don’t water them enough & they don’t flower. Eventually years of such mistreatment will kill them, too.
@milodonharlani 4:23 pm
We’re right back where we were.
I don’t know about you, but I’ve made progress. This has been a thought provoking discussion and I thank you.
As I understand your argument,
1. Atmospheric pressures have changed,
2. but only by a fraction of a bar
3. [O2] has changed, but in the range of 15%(hypooxic) to 35%(spontaneous combustion)
4. [N2] has remained constant. There is no mechanism to gain or loose significant amounts of N2 from the atmosphere.
5. [CO2] has been under 0.5% in the Phanerozoic and as such is insignificant in terms of pressure.
6. No other gases move the needle.
So the only changes to air density come from changes of +/- 0.1 bar of O2 and maybe a minor loss of N2 escaping to space.
I’ve been coming at it from an aerodynamic point of view.
1. Atmospheric pressurs have change,
2. and have been on a long term decline.
2a. We loose gas to space, preferentially loosing lighter molecules
3. [O2] has changed, but in the range of hypooxic to hyperoxic – spontaneous combustion. Gaia is in charge when it comes to Oxygen.
4. Hmmm. The Amount of N2 in the atmosphere is a hard nut to crack. If the earth can retain H2O, it should retain N2.
http://abyss.uoregon.edu/~js/ast121/lectures/lec14.html>
4b. NH3 isn’t an escape vector, it is only a little lighter than H2O.
4c. Nitrogen doesn’t make up minerals.
4d. Nitrogen isn’t not as big a component of biology as is C and O2.
5. [CO2] has been under 0.5% in the Phanerozoic and as such is insignificant in terms of pressure. — Wait a minute!
5a. How do we know that?
Really? Only 12 times more than today?
How much carbon is accounted for in CO2 in the atmosphere compared to other places: (See Wiki: Carbon Cycle) in gigatons
Atmosphere: 720 GT
Fossil Fuels: 4,130 GT (90% coal and peat)
Terrestrial biosphere: 2,000 GT (living and dead)
Ocean organic: 1,000 GT
Ocean inorganic: 37,400 GT
Lithosphere Kerogens: 15,000,000 GT
Lithosphere Carbonates: more than 60,000,000
There is 100,000 times more carbon locked in terrestrial Kerogen and carbonates than is in the current atmosphere. These are all BIOLOGIC and for the most part formed in the Phanerozoic. Where did all that carbon (and oxygen!) come from if it wasn’t in the atmosphere/hydrosphere 700 Mya?
Today’s [CO2] has a partial pressure of 0.0004 bar. If we unlock all those carbonates and kerogens and return them to the atmosphere, the partial pressure would be 40 bar.
Ok, that was a real rough back-of-the-envelope guesstimate. We can hide some of that in the oceans, maybe all of it. Max solubility is 3 g / kg of water.
Or we need 330 GT water for each GT of CO2. We’d have 75,000,000 GT = 250,000,000 GT CO2. So we need 90,000,000,000 GT = 9.0E+10 GT water to dissolve it.
Mass of the Ocean (Hypertextbook): 1.37 × 10^21 kg = 1.4E+18 ton = 1.4E+09 GT
So we can dissolve only about 1.5% of the CO2 in the ocean.
I still have a 40 bar CO2 atmosphere untill we can start creating carbonates.
The problem isn’t how do we get N2 concentrations to jump un and down, but how do we account for all this Carbon, which is probably in CO2, before we lock it up in carbonates? How does life operate in a hyperbaric mix of CO2 and O2?
So, how the heck can we have a 0.5% CO2 atmosphere at the start of the Phanerozoic before we have created carbonates in mass and organic kerogens buried in sedimentary rocks. Was the carbon locked up in algal mats and stromatalite mounds?
Stephen Rasey says:
October 8, 2013 at 10:43 pm
I’m glad you’ve found our discussion worthwhile.
How much N2 might leak to space I don’t know, but seems not a lot. A possible mechanism for removal of a little I noted above, ie combination with “excess” oxygen during the catastrophic K/T impact event atmosphere, but that would be just a fraction at most & might have been returned to the air during the Cenozoic.
I haven’t addressed your aerodynamic arguments, since I feel the links to pterosaur research I’ve posted adequately address those issues. Giant Carboniferous arthropods IMO are explained by high O2, not a much denser atmosphere. It wasn’t just flying insects but ground-dwelling & burrowing arthropods as well which grew enormous.
While there has been geologic uptake of CO2 during the Phanerozoic, the main force drawing down the gas from atmospheric concentrations on the order of 10,000 ppm to 100 ppm has been land & sea photosynthesizers, plus cooler oceans.
There just hasn’t ever been enough CO2 in earth’s air for about the past 2.7 billion years to get total pressure much higher than twice present density. In the early eons, it was taken up by rocks & later by life, despite additions from volcanism. It might have regained the 10% level during Snowball Earth intervals, but I don’t know how much physical evidence there is for that, as opposed to purely hypothetical.
IMO the raindrop study’s finding of a max of 2.0 bar 2.7 Ba makes sense. Sure I’d like to see confirmatory studies, but the picture of atmospheric evolution which it paints cannot be easily falsified, or at least hasn’t yet been, that I’ve found.
But it’s good to have people challenging every emerging orthodoxy.
@milodonharlani 8:19 am
There just hasn’t ever been enough CO2 in earth’s air for about the past 2.7 billion years to get total pressure much higher than twice present density. In the early eons, it was taken up by rocks
That’s the part I’m challenging. How do we know the partial pressure of CO2 at the start of the Phanerozoic was less than 0.01 bar?
Photosynthetic life created oxygen and the Banded Iron Formations of the Archean. Here is an interesting page on Chapter 11: Climate Regulation and Atmosphere Evolution through Geologic Time
A couple of quotes about that caught my eye:
Point 1 is weak evidence. We don’t see evidence of high acidic rain. We don’t know a lot about the Archean. What else is in the atmosphere to buffer the solution? But it is an issue I cannot ignore.
Point 2 is interesting. If life is necessary to fix hydrogen to oxygen to form water, and thereby keep from losing H2 to space, it is profound. I guess it follows from life isn’t necessary to combine oxygen and hydrogen, but the oxygen is rare without life to make it available to hydrogen.
Point 3 is the killer. Black shales. I guess I found my Archean carbon sink. I cannot contest that there will be long term preservation — the oceans will be very hypoxic. These Black shales will be subducted and the carbon will return via volcanism later. But it is a very real avenue to remove CO2 from the atmosphere, sink the carbon and hydrogen and liberate oxygen for the formation of minerals, thus reducing the atmospheric pressure.
So I’ll have to reduce my range of paleoatmospheric pressures. I’m not ready to discard the aerodynamic argument yet. But I’ll have to give greater weight to the proposition that O2 Partial pressure today the limiting factor on flight and not total atmospheric density.
Thanks for the conversation.
Stephen Rasey says:
October 9, 2013 at 12:54 pm
As you know, there is a wide range of error bars on Cambrian CO2 estimates from paleosols & other data, but 7000 ppm is the usually cited best guess.
You’re welcome. Thank you.
Stephen Rasey, October 8, 2013 at 10:43 pm
milodonharlani, October 9, 2013 at 1:11 pm
An interesting conversation. Thanks for the collection of useful parameters Stephen, I particularly liked the comment about the Archean black shales acting as a carbon sink.
In this post I have concentrated on the point that cold water absorbs gas from the atmosphere, and only alluded to the converse point that warm water expels gas back into the air, without giving any details of how this process is achieved for the carbon dioxide that is chemically bound in sea water. Atmospheric carbon dioxide gas dissolves readily in cold fresh water (for example raindrops) and forms the mild acid, carbonic acid. The standard chemical test for carbon dioxide is to bubble a sample of gas through lime water, which is a solution of the alkali chemical calcium hydroxide.
Carbonic acid combines with lime water to form a milky white precipitate of the insoluble salt calcium carbonate (acid plus base forms a crystalline salt plus molecular water). If however you continue the test and bubble more carbon dioxide gas into the cloudy water, another change occurs, the milky white precipitate of calcium carbonate disappears as water soluble calcium bicarbonate is formed.
Limestone is unusual among the sedimentary rocks in that its mineral calcite is formed by precipitation as dissolved calcium bicarbonate in seawater is converted to insoluble calcium carbonate with the expulsion of a carbon dioxide molecule. This geochemical process readily occurs in warm agitated sea water, such as the beach swash zone of a tropical coral island, where oolitic carbonate sand grains are abundantly created. Although we primarily think of limestone as being an organic deposit, in fact half of the limestone rock found in sedimentary strata is inorganic in origin. Nature has merely adopted the chemical process of calcite mineral precipitation for its own purposes.
I need to revise a previous essay about carbonate rocks that was posted elsewhere and develop this theme more fully.
@Philip Mulholland 5:00 pm
I look forward to reading about the inorganic carbonate processes.
The same time as I was mulling over the potential 40 bar CO2 atmosphere, I checked the mineralogy of the Banded Iron Formation. What I found was that the non-iron bands were sands and cherts instead of carbonates.
There are two pregnant questions here.
First, why not inorganic carbonate between the iron bands? Was it Ph? At what Ph ranges does inorganic carbonate deposit, probably dependent upon some other parameter, like temperature.
Second, the banding of the formation illustrates many thousands of climate changes that starts and stops the deposition of iron. The time frame of this would be fascinating. Is this going on during the acid rain, leaching continents with seasonal fluxes of eroded minerals.
Philip Mulholland says:
October 9, 2013 at 5:00 pm
I’m glad that our discussion on past atmospheric pressures arising from Mesozoic pterosaur & Paleozoic dragonfly flight has been of some use to your work on carbonate rocks, in particular Stephen’s comment on Archean black shales. This is an example of how blogs can help advance science, whether amateur or professional.
A closing reflection:
This is a chart of Paleo atmospheric composition over the whole history of the earth.
I have some technical problems with it. The overlap of the Water Vapor and Carbon Dioxide areas screws up the Nitrogen areas.
But the biggest problem with this and other similar composition charts gets back to the overall discussion on atmospheric pressure. This type of chart boxes you into thinking about constant pressure and all that is changing is the relative composition. The present is NOT the key to the past; it only hints at the past. Just because today it is 1 atm, shouldn’t lock you into thinking it was always 1 atm.
My enlightenment this week has been in the mineralization of the Archean CO2. I am going to have to accept that by the beginning of the Phanerozoic the atmospheric pressure is probably under 5 atm and likely under 2.5 atm. But I’m probably more convinced than ever that at the beginning of the Archean, at the dawn of photosynthetic life, we see partial pressures of CO2 in the 10 – 80 bar range. Our atmosphere didn’t escape into space — life turned CO2 from gas into solid by transforming CO2 into hydrocarbons, oxides, silicates and free oxygen. The end of the Archean is less an end of high CO2 partial pressures, but an end of the acidic – neutral oceans as life-generated free oxygen precipitated out the cat-ions from the oceans. In the Proterozoic, CO2 partial pressures can (must?) continue to fall as life continues to generate O2 and lock up C in Carbonates.
So Atmospheric Composition charts needs to be created in a stacked area chart of partial pressures or by TeraTons. (Partial pressure (at sea level) would be preferable, but sea level adds noise to the calculation.) In this chart, we have 1/2 of a Venusian atmosphere at the beginning of the Archean (60 bar) and over 2.5 billion years it drops to under 2-4 bar by the beginning of the Pherozoic.
A companion chart of ocean composition (pH, O2, sulfur, metals, isotope ratios) should parallel the atmospheric chart.
Viewed in this light, a fall of CO2 partial pressures and total atmospheric pressures with corresponding drop in temperatures via lapse rates, a Snowball Earth scenario is not only possible, but maybe inevitable.
Refs:
Grotzinger 2010, “PreCambrian Carbonates: Evolution of Understanding”
Grotzinger 2009, Archean Oceans cooler, better for origin of life
Hydrogen deuterium ratio in Archean cherts is lighter than today. Loss of H2 to space over time to change the ratio.
Stephen Rasey says:
October 10, 2013 at 11:26 am
From the Oct 4, 2013 edition of Science:
http://www.sciencemag.org/content/342/6154/101.short
“Understanding the atmosphere’s composition during the Archean eon is fundamental to unraveling ancient environmental conditions. We show from the analysis of nitrogen and argon isotopes in fluid inclusions trapped in 3.0- to 3.5-billion-year-old hydrothermal quartz that the partial pressure of N2 of the Archean atmosphere was lower than 1.1 bar, possibly as low as 0.5 bar, and had a nitrogen isotopic composition comparable to the present-day one. These results imply that dinitrogen did not play a significant role in the thermal budget of the ancient Earth and that the Archean partial pressure of CO2 was probably lower than 0.7 bar.”
This finding comports well with the raindrop study, which put maximum atmospheric pressure 2.7 Ba at two bar.
@milodonharlani 8:52 am
RE: Marty et al. 2013, Nitrogen Isotopic Composition and Density of the Archean Atmosphere
Bernard Marty, Laurent Zimmermann, Magali Pujol, Ray Burgess, and Pascal Philippot
Science 4 October 2013: 101-104.Published online 19 September 2013
Thanks. And Wow. But check out the pod cast at
http://www.sciencemag.org/content/suppl/2013/09/18/341.6152.1409-b.DC1/SciencePodcast_130920.pdf (171 KB) from 18:56 to 27:21.
(11:30 am continued)
Earlier in the podcast transscript there is this:
From this, there seems to be a leap of faith that what they measured was indicative of surface water in saturation equilibrium with the atmosphere. But they may be measuring the composition of the gasses in the hydrothermal water as H4SiO4 precipitates out as silica as the water gradually cools and/or reduces pressure. See. The Quartz Page
Also, why didn’t they measure CO2 directly? Or at least Carbon content? Was the ratio of N2/Ar important to the process, and therefore a critical assumption?
Stephen Rasey says:
October 11, 2013 at 11:30 am
On WUWT, you’ll find extensive discussion of why the supposed paradox of a weak early sun & liquid watery earth isn’t so paradoxical. Very high levels of GHGs don’t need to be invoked.
That said, CO2 at 0.7 bar in an atmosphere no denser than 2.0 bar is still a lot of CO2 to be drawn down geologically & biologically to perhaps 7000 ppm in less thick air by 543 Ma from 2700 Ma.
@milodonharlani 11:49 am
Going on the rough calculations from 10/8 10:43 pm>,
Atmosphere: 720 GT Carbon with CO2 at 400 ppm = about 0.4 mbar.
so roughly 1800 GT Carbon per mb CO2.
So, 7000 ppm is about 7 mbar or about 12,000 GT Carbon. (at begining of Phanerozoic)
700 mb would be 1,200,000 GT Carbon in the atmosphere.
But locked up in rocks today is about 75,000,000 GT of Carbon in carbonates and kerogens. Most of this carbon was in the biosphere from the start of time, and probably in the form of CH4 and CO2. I think we need to account for this mass in the Archean when oceans were ferrous and oxygen starved, beforee the Banded Iron Formation are precipitating out.
Going from 700 mb to about 7 mb or 1,200,000 GT to 12,000 GT Carbon in 1200 Ma in the mid-Archean to Proterozoic is child’s play compared going from 75,000,000 GT of carbon (somewhere) to 1,200,000 GT (atmoshpere) in the first 800 Ma of the Early-mid Archean.
(repost of 1:24 pm)
@milodonharlani 11:49 am
Going on the rough calculations from 10/8 10:43 pm,
Atmosphere: 720 GT Carbon with CO2 at 400 ppm = about 0.4 mbar.
Roughly 1800 GT Carbon (atmosphere) per mb CO2.
So, 7000 ppm is about 7 mbar or about 12,000 GT Carbon. (at begining of Phanerozoic) 700 mb would be 1,200,000 GT Carbon in the atmosphere.
But locked up in rocks today is about 75,000,000 GT of Carbon in carbonates and kerogens. Most of this carbon was in the biosphere from the start of time, and probably in the form of CH4 and CO2. I think we need to account for this mass in the Archean when oceans were at pH 6 to 7.5 while the Banded Iron Formation are precipitating out.
Going from 700 mb to about 7 mb or 1,200,000 GT to 12,000 GT Carbon in 1200 Ma in the mid-Archean to Proterozoic is child’s play compared going from 75,000,000 GT of carbon (somewhere) to 1,200,000 GT in the first 800 Ma of the Archean.
Stephen Rasey says:
October 11, 2013 at 1:24 pm
I don’t know if that much carbon was drawn down during the Archean (between 4 Ba & 2.5 Ba), but I do find atmospheric pressure no more than twice present density by 2.7 Ba convincing at this point.
Don’t recall if you’ve seen this 2010 Cold Springs Harbor study of the early atmospheres:
http://cshperspectives.cshlp.org/content/2/10/a004895
Abstract
“Earth is the one known example of an inhabited planet and to current knowledge the likeliest site of the one known origin of life. Here we discuss the origin of Earth’s atmosphere and ocean and some of the environmental conditions of the early Earth as they may relate to the origin of life. A key punctuating event in the narrative is the Moon-forming impact, partly because it made Earth for a short time absolutely uninhabitable, and partly because it sets the boundary conditions for Earth’s subsequent evolution. If life began on Earth, as opposed to having migrated here, it would have done so after the Moon-forming impact. What took place before the Moon formed determined the bulk properties of the Earth and probably determined the overall compositions and sizes of its atmospheres and oceans. What took place afterward animated these materials. One interesting consequence of the Moon-forming impact is that the mantle is devolatized, so that the volatiles subsequently fell out in a kind of condensation sequence. This ensures that the volatiles were concentrated toward the surface so that, for example, the oceans were likely salty from the start. We also point out that an atmosphere generated by impact degassing would tend to have a composition reflective of the impacting bodies (rather than the mantle), and these are almost without exception strongly reducing and volatile-rich. A consequence is that, although CO- or methane-rich atmospheres are not necessarily stable as steady states, they are quite likely to have existed as long-lived transients, many times. With CO comes abundant chemical energy in a metastable package, and with methane comes hydrogen cyanide and ammonia as important albeit less abundant gases.”
It goes on to discuss the first & second atmospheres. It says the earliest atmosphere consisted of gases from the solar nebula, primarily hydrogen, plus probably simple hydrides such as now found in Jupiter & Saturn, ie water vapor, methane & ammonia. As the solar nebula dissipated, these gases would have escaped, partly driven off by the solar wind.
The second atmosphere consisted largely of nitrogen plus CO2 & inert gases, released by volcanic outgassing, supplemented by gases produced during the late heavy bombardment of Earth by huge asteroids. A major part of the CO2 emissions were soon dissolved in water & built up carbonate sediments, as we agree.
What happened later in the Archean has been hypothesized by Jan Veizer (March 2005) in Geoscience Canada, “Celestial Climate Driver: A Perspective from Four Billion Years of the Carbon Cycle”, sometimes cited in this blog:
http://www.gac.ca/wp/wp-content/uploads/2011/09/GACV32No1Veizer.pdf
I’m well aware of the theory of impact formation of the moon. It is a whole chapter of Rare Earth. And until a few days ago, I thought that was the chief reason for our thinner atmosphere than Venus. It probably still plays a big part in Earth starting off with a leaner atmosphere after the impact. But the carbon mass balance is the problem to be solved.
http://www.gac.ca/wp/wp-content/uploads/2011/09/GACV32No1Veizer.pdf
Figures 5 and 6 pertain to the Phanerozoic, but little about the PreCambrian. No references to iron, Archean. But this caught my attention:
Ten thousand times 0.4 mbar is 40 bar. (How about that!?)
My 40 bar came from a mass balance from estimated mass of rocks. This is a value from what is necessary to warm the earth. (However, the estimated mass of rocks might have been from a circular assumption somewhere).
[1] this is a problem. But we are not dealing with sea water as we know it here. We have a reducing mineral soup before the Banded Iron Formations are deposited by oxygen generated by life. The number of ionic equilibrium equations in play is mind boggling.
Hadian Ocean Carbonate Geochemistry (Morse 1998)
http://www.minersoc.org/pages/Archive-MM/Volume_62A/62a-2-1027.pdf
This paper mentions Na+, Ca+2, Cl-, K+, Mg+2 concentrations makes no comment about Fe+2 or Fe+3, iron, or ferric or ferrous conditions. So I think the paper missed the boat on a major condition of the Archean oceans.
Correction to 2:20 pm
Ten thousand times 0.4 mbar is
404.0 bar.(How about that!?)The questions on my mind at the moment for later is:
How did we get a dissolved iron rich ocean in the first place?
One answer with a CO2 rich atmosphere, we have carbonic acid rain. It falls on continents and dissolves out the metals.
What are the chemical reactions mass balances?
Any chance the carbon is parked on land as a carbonate?
Or even a hydrocarbon like methane?
Was early Earth a Titan atmosphere until life oxidized the iron in the oceans?
Stephen Rasey says:
October 11, 2013 at 2:44 pm
Titan’s atmosphere has indeed been proposed as a model for Earth’s second atmosphere, in that it’s mainly nitrogen, with a surface pressure about 1.45 times ours at present. However, its mix of organic molecules is different from the early Earth’s, in which CO2 appears to have been an important constituent, as it remains on Venus & Mars.
Maybe the early Archean atmosphere was 4.0 bar (at 4.0 Ba, which is neat), dropping down to under 2.0 bar by 2.7 Ba. I’m glad you’re on the case. I hope you’ll write up your conclusions.
@2:44 pm
In short, what happens when you drop carbonic acid on basalt?
Also, let’s not forget sulfuric acids (H2SO4) with sulfur derived from FeS2 (iron pyrite) and possibly H2S in the atmosphere (but this wlll require free oxygen
nitric acid seems to require free oxygen.
@milodonharlani 3:17 pm
Early earth had CH4 and lots of UV, so the CH4 + UV to C2H6 + H2 reaction had to be working. Titan is cold enough for CO2 to be solid.
I’m glad you’re on the case.
Keep those references coming…. at least as long as this thread remains open. I would have missed the Marty paper. So thank you.
One last post today… got to move on.
From Cowen, Richard: “The History of Life” 4th edition. p.6:
[1] Would the pH of the oceans allow that to happen? Dissolved CO2 forms a pH = 4 acid. See Bjerrum Plot What buffers the oceans to keep pH high and allow carbonates to form?
Stephen Rasey says:
October 11, 2013 at 4:40 pm
Basalt. All the volcanism that spewed forth CO2 gas also produced seas of lava.
Back to Cold Springs:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2869525/
From the Cold Springs link above:
I think there are some important inconsistencies here.
The premise is that inorganic carbonates can form in a hot 500K ocean at 100-300 bars CO2 and H2O pressure.
[3] “in equilibrium with basalt” That is interesting chemistry. But carbonates will need to be widespread, blanketing basaltic crust which makes for equilibrium conditions only at the contacts.
[5] puts a limit on CO2 sequestration on the sea floor
[6] says that repeated overturning is the answer sequestering more CO2
but [1] and [2] imply that carbonates once subducted cannot stay sequestered for long. Sequestered carbon will pop out of the volcanos immediately in geologic terms.
I look forward the Phillip Mulholland’s paper on carbonates. Aqueous reducing pressure-cooker chemistry at 500 K and 100+ atmospheres might yield surprises.
Stephen Rasey says:
October 12, 2013 at 9:36 am
If Earth once had a Venusian-style atmosphere, more than just distance from the sun must explain its chemical evolution & loss of density, especially considering that our planet has an internal magnetosphere. It appears that both geology & biology contributed. It’s tempting to imagine that life remakes the world to be cozy for it, but this view ignores the fact that the first microbes producing O2 almost wiped out those that didn’t.
I too look forward to Mulholland’s further research.
It’s tempting to imagine that life remakes the world to be cozy for it, but this view ignores the fact that the first microbes producing O2 almost wiped out those that didn’t.
Yes, that was a climate change for the ages.
I read about another such episode, something called the “Sulfur Crisis” by one. For a great length of time algae formed extensive mats, building upon itself like corals build reefs. Below that mat was a poisonous H2S rich organic substrate. One day, a form of life evolved to burrow into that treasure trove and survive the H2S environment. That life proliforated, liberating millions of years of sequestered sulfur back into the environment to the great harm of other life forms that liked things as they were.
If you Google “sulfur catastrophe” you will find Rotten sulfur brew, the great dying. This describes a theory of the Permian Extinction.
What I remembered was a stage in late Archean or Early Proterozoic. I can’t find the link at present.
Stephen Rasey says:
October 12, 2013 at 11:08 am
H2S poisoning is indeed a leading candidate as cause or contributing factor in the P-Tr “Great Dying” or “Mother of All (Phanerozoic) Mass Extinction Events”. The link below suggests it as a factor in the Late Devonian MEE & Cenomanian–Turonian minor extinction, too.
As for the Proterozoic, the 2005 “Geology” paper doesn’t posit a relatively short catastrophic event, but that persistently high levels of H2S in the air might have hampered the evolution of eukaryotic life on land during that long Eon.
http://geology.gsapubs.org/content/33/5/397.full
Maybe that’s not what you had in mind, though.
vigilantfish at October 6, 2013 at 8:45 pm
You ask
Maybe this superb movie (thanks JimS) illustrating the melting of the Laurentide Ice Sheet will help. Twenty thousand years ago the site of Hudson’s Bay was buried beneath the centre of the Laurentide Ice Sheet and the weight of the ice depressed the continental crust. Following the melting of the both northern hemisphere ice sheets of North America and Northern Europe, global sea level rose and this region flooded, creating the modern shallow water bay. Unlike the Weddell Sea there is no major ice cap nearby to create a katabatic wind, so the process of active continuous wind assisted formation of cold dense salty water does not occur.
Berényi Péter at October 6, 2013 at 12:03 pm
You say:
If you ever have the opportunity of visiting Scotland’s capital city, as I did recently, and your flight approaches Edinburgh airport from the west, you will see as your plane descends over West Lothian some remarkable landform features north of Broxburn, near the town of Livingston.
The red mounds visible from the air are the shale bings left over from the industrial process of extracting oil from Carboniferous cannel (candle) coal invented by James “Paraffin” Young.
If the process of heating Carboniferous organic rich shale to extract oil works in an industrial retort in a factory, then it is clear that the missing component in this process is heat. If the same shales were heated at depth within the Earth by geothermal means, then oil would similarly be naturally expelled from this organic rich shale by natural pyrolysis.
grumpyoldmanuk at October 6, 2013 at 9:37 pm
Hello Kevin,
I am afraid that your library search will have drawn a blank, as I have not published much.
I am a professional geoscientist with a BA in Environmental Sciences from The University of Lancaster in 1974 and an MSc in Conservation from University College London in 1981, where I studied the natural regeneration of woodland in Epping Forest using a Markovian Matrix technique to determine the temporal balance between Birch, Oak and Beech trees in a successional replacement cycle.
I started my career in the Institute of Geological Sciences (now the British Geological Survey) where I worked with trained geological experts. Geology is a field science and the best geologist is the person who has seen the most rocks. I am a generalist by aptitude and therefore rely on the field work of specialist when attempting to understand the interlocking complexities of geoscience.
I now work in industry and am doing my bit to protect the natural world by ensuring that forest trees are not needlessly burned in power stations in a specious effort to reduce carbon dioxide emissions.
Hi. Philip. Thanks for replying to my question, which I hope you did not find impertinent. I hope your quest to install a little common sense into power generation meets with some success.