From the European Association of Geochemistry, a claim that looks to be little more than paleo-dowsing. Though, ya gotta love the silly claim that Earth would have hit a runaway greenhouse effect like Venus, had it not been for some mountains forming, sucking up all the CO2. Plus we’ve seen the Earth hit 5000PPM CO2 in the past, and it didn’t turn into Venus. This (Figure 1) from this post at the Met Office.
Of course it all just more model output, there’s no real earth science going on -all guesswork, no actual measurements.
How Earth avoided global warming, last time around
Geochemists have calculated a huge rise in atmospheric CO2 was only avoided by the formation of a vast mountain range in the middle of the ancient supercontinent, Pangea. This work is being presented to the Goldschmidt geochemistry conference in Sacramento, California.
Around 300 million years ago, plate tectonics caused the continents to aggregate into a giant supercontinent, known as “Pangea”. The sheer size of the continent meant that much of the land surface was far from the sea, and so the continent became increasingly arid due to lack of humidity. This aridity meant that rock weathering was reduced; normally, a reduction in rock weathering means that CO2 levels rise, yet in spite of this CO2 levels – which had been falling prior to the mountain formation- continued to drop, eventually undergoing the most significant drop in atmospheric CO2 of the last 500 million years. This phenomenon has remained unexplained, until now.
Now a group of French scientists from the CNRS in Toulouse have produced a model which seems to explain this contradiction. The period coincides with the rise of a vast series of mountains in the interior of Pangea, the “Hercynian” mountains”. These mountains arose in a wide belt, running from what is now the Appalachians, through to Ireland, South-Western England, through Paris and the Alps into Germany, and on further East.
According to team leader, Dr Yves Godderis (CNRS, Toulouse, France):
“The formation of these mountains meant that the rock weathering, which was threatening to slow to a walk through much of the supercontinent, was able to continue. The steep slopes of these Hercynian mountains produced physical erosion. Occurring in a humid equatorial environment, this physical erosion promoted rock weathering and removing CO2 from the atmosphere”.
He continued, “We believe that it is this which led to the dramatic drop in atmospheric levels of CO2. We estimate that if it hadn’t been for the formation of the Hercynian mountains, the atmospheric CO2 levels would have reached around 25 times the pre-industrial level, meaning that CO2 levels would have reached around 7000 ppm (parts per million). Let me put that into a present-day context; the current atmospheric CO2 levels are around 400 ppm, so this means that we would have seen CO2 rise to a level around 17 times current levels. This would obviously have had severe effects on the environment of that time. But the formation of the mountains in fact contributed to the greatest fall in atmospheric CO2 in the last 500 million years”.
The team believes that even if the mountains had not formed and CO2 levels rose sharply, this would not have led to a runaway greenhouse effect as happened on Venus, because the increasing temperatures would have led to rocks being ultimately weathered, heat compensating for the scarcity of water. Rock weathering would have removed CO2 from the atmosphere, thus stopping the rising temperatures.
“So it would eventually have been self-correcting” said Dr Godderis, “but there’s no doubt that this would have stalled Earth’s temperature at a high level for a long, long time. The world would look very different today if these mountains had not developed when they did.
This is a new model which explains some of the events in the 80 million years following the start of the Carboniferous period, and of course the ideas need to be confirmed before we can be sure that the model is completely accurate. The take-home message is that the factors affecting atmospheric CO2 over geological periods of time are complex, and our understanding is still evolving”.
In Cosmos episode 12, Carl Sagan’s protoge Neil dg Tyson uses the same switcheroo from a hellish Venus to what will happen on Earth if we don’t reduce man-made CO2. – all designed to scare the kiddies witless – “good one Neil” – NOT.
I made it about 6 minutes past that presentation in Cosmos and then closed the window to Hulu on my computer. I will never consider another word Tyson speaks again.
I really wish somebody would tear apart the lies presented in this latest Cosmos.
‘The take-home message is that the factors affecting atmospheric CO2 over geological periods of time are complex, and our understanding is still evolving”.’
The science isn’t settled?
“The team believes that even if the mountains had not formed and CO2 levels rose sharply, this would *not* have led to a runaway greenhouse effect as happened on Venus”.
“Understanding Still Evolving”. Precisely!
What I find interesting (and vaguely disturbing) is the apparent long term diminishing trend of CO2 in the Earth’s atmosphere. If I recall correctly, and please feel free to inform me otherwise if I’m mistaken, plants can start to run into problems with photosynthesis when CO2 falls below 150-170 ppm. Now, given that pre-industrial levels of CO2 were at 270(?) ppm, it seems to me that we weren’t too far away, geologically speaking, from some sort of REAL crisis and perhaps permanent mass extinction of the more complex life on Earth.
An idea which has occurred to me is that planetary eco-systems are something of a “biological battery”, where CO2 is the major organic fuel/component. Over deep time the CO2 is removed via organic/non organic means, eventually to a point of near depletion, making complex life non viable. Effectively the battery becomes discharged or in other words, “flat”!
Seems to be as good an explanation for the Fermi Paradox as any.
Oh, BTW, has anybody got any reliable figure/estimations regarding the quantity of CO2 generated by beer, sparkling wine, soft drinks etc.? Seriously…
[TO ANTHONY: I’d thought about broaching this idea a while ago but this post seemed an opportune time to do so. Thanks for all your effort.]
I was very much disappointed with NDT’s views on CO2. Even more disturbing is a short YouTube video in which he attempts to explain “climate” and “weather” using a dog on a leash. Simplistic and mis-leading.
I’ve given up on Cosmos.
They got the timing completely backwards here.
CO2 fell steadily from about 380 million years ago until it reached a low plateau starting about 320 million years ago lasting to 265 million years ago, getting down to about 350 ppm.
This happened before the formation of Pangea and the Central Pangean Mountains which started forming about 265 million years ago. CO2 started rising rapidly about 265 million years ago just as these mountains started forming.
The CO2 drawdown happened at least 100 million years before the mountain building phase. More in line with when Gondwana was over the south pole and the large glaciers of the Carboniferous formed here. Europe and North America were actually very flat at the time and were actually off-and-on flooded by the ocean during the low CO2 point. What often happens in cold ice age conditions (like the Carboniferous), CO2 levels are drawn down.
Overall, this study is just scientists who know nothing about the timelines but have a creepy fascination with the word “weathering” which many CO2 warming proponents also have.
Critical Zone and Carbon Cycle in the Deep Time by Yves Godderis
Abstract (Godderis Y, Donnadieu Y & Carretier S)
[My Bold]
The large scale spreading of vascular plants decreased the albedo of the continents, leading to a paradoxal climatic evolution in which an ample decrease in atmospheric CO2 over the course of the Devonian period might have occurred at roughly constant continental temperatures3. This study also emphasized the key role played by land plants on the continental hydrologic cycle.
http://goldschmidt.info/2014/uploads/abstracts/finalPDFs/817.pdf
In light of more CO2 equals higher temps, I would like to see an explanation for the roughly constant temperatures.
Don’t you just love these new fangled computer models. They can take arid environments and turn them into humid equatorial environments just by growing some mountains. No mention of how tall the mountains were… I wonder how many mountain passes the computer modelers programmed in.
Steep slopes of the Hercynian mountains… Steep? I suppose the model required steep mountains for some reason? The odd thing about steep mountains is that above certain altitudes, they tend to keep moisture as perennial snowcaps. Steep mountains with heights under the snowcap level look sort of funny if they’re mesa shaped.
Mountains on Earth have difficulty retaining steep slopes because gravity wins. Weathering is a complex process where the more complex the mineralization, the quicker the weathering. There are exceptions where large resistant granitic massifs are elevated. But whole mountain chains composed of massifs are about as believable as funny models.
Bill Illis says:
June 11, 2014 at 9:22 pm
How this study’s authors managed to ignore the Late Carboniferous (Pennsylvanian) glaciation needs explaining. Maybe they discuss it in the paper.
CO2 fell in the Pennsylvanian (323 to 299 Ma) because of a long, deep glaciation, which persisted into the Early Permian. Colder T meant more of the gas in the oceans & less in the air.
Previously (during the Mississippian, (359 to 323 Ma) it fell due to the then luxuriant growth of land plants, which made the eponymous Carboniferous coal beds, especially before the development of advanced fungi to help break down rotting vegetation.
Golly-Gee Mr.Wizard !! I always thought all that CO2 went into the coal beds & limestone deposits (and other carbonate bedrock) laid down during the Carboniferous age which was, curiously enough ~360 million years ago. Curiously enough, this coincides nicely with their graph’s descent from 2000+ ppm CO2 to low levels. Who would have thunk it ??
Let’s do an experiment and burn every lump of coal (think of all those bad-boys) & lime up every ounce of limestone and see what happens !! Dodge that ….
” Rock weathering would have removed CO2 from the atmosphere, thus stopping the rising temperatures.”
==============
Not a word in regards to salt water /heat capacity.
cnxtim said: “In Cosmos episode 12, Carl Sagan’s protoge Neil dg Tyson uses the same switcheroo from a hellish Venus to what will happen on Earth if we don’t reduce man-made CO2. – all designed to scare the kiddies witless – “good one Neil” – NOT.”
I haven’t even bothered. I am 30 but I remember my dad getting the cosmos series on VHS in the mid-90s. I was mesmerized. It had a huge effect on my understanding of the world and, to this day, I will go back and watch various little snippits.
The beauty of it: as it was put together in the late 70s (I believe), there wasn’t one mention of climate change. It was just science. It makes me sad to think what I would have missed out on if it hadn’t been produced when it was, before anything scientific had to have a CAGW-related footnote on every Godd**n release.
Our kids are being robbed and the villians won’t be satisfied until they have their souls. Oh, silly me. That’s right: ‘souls’ are religious, mystical fluff. How could I be so unscientific?!? They have now been replaced by the NRDC mission statement and offset by carbon credits.
Maybe the reconstruction of Earth’s atmospheric history has changed since I last read about it, but as I recall, after Earth finished accreating it’s atmosphere was very like that of Venus. Then massive amounts of carbon dioxide were sequestered by the formation of carbonate rocks, mainly by reaction with calcium and magnesium ions in the oceans. So the reason Earth is not like Venus is because Earth had literaly oceans of water from very early on.
“Plus we’ve seen the Earth hit 5000PPM CO2 in the past, and it didn’t turn into Venus.”
Also, 5000ppm although larger than 400ppm is still not significant compared to 965,000ppm. as on Venus. If CO2 is that effective that small variations of between 300ppm to 5000ppm can have large temperature effects then 965,000ppm should have turned the surface of Venus molten?
Just asking.
“runaway greenhouse effect as happened on Venus” ?
Venus is a newcomer in the solar system and it is slowly cooling down and speeding down its rotation velocity. There is no runaway greenhouse effect on Venus.
Robertvd says:
June 12, 2014 at 12:25 am
“runaway greenhouse effect as happened on Venus” ?
“… and speeding down its rotation velocity. ”
Can it go any slower?
Venus, tropopause 70K above the surface, surface atmospheric pressure 92bar, insolation less than half that of earth due to very high albedo, (0.67) atmospheric lapse rate 10.2C/km surface temperature over 700K due to ADIABATIC COMPRESSION.
jiohnmarshall says:
“surface temperature over 700K due to ADIABATIC COMPRESSION”.
Sorry, but no, compression only heats a gas when pressure is increasing and energy is added to the system. Strange that this seems to be so difficult to understand.
It is true that the high temperature on Venus’ surface is due to the depth of the atmosphere and the lapse rate, but the temperature profile is due to convection.
‘Plus we’ve seen the Earth hit 5000PPM CO2 in the past, and it didn’t turn into Venus’, well even 300,000ppm! But if you research deep enough there is a reason for everything. Anyhow Venus is not the Earth, there are differences.
CO2 300,000 ppm but snowball Earth, followed by hot house Earth!
‘a puzzle called the faint sun paradox is explained by the warming effect of GHG, mostly co2…but if co2 fell it wouldn’t take much to tip the world into an ice age…a positive feedback leading to more cooling, more ice, more reflection, until nearly all the world was covered by ice…there is no way the Sun could melt all this ice,…but something did…because the Earth turned into a hothouse…geologists say the reason is very simple, the only part of the Earth not covered by ice was warm spots caused by volcanoes…but they did release gases..,co2 under normal conditions this would have reacted with rocks and rainfall and get washed out to sea…but in snowball Earth, there is no rain, no weathering…so the co2 just keeps building up…so you have high co2 levels with glaciers at the equator but this is a dynamic process, it doesn’t stay like this’.
Now see for yourself!
Mountain building takes place over many millions of years. CO2 climate sensitivity is so fast it takes place in a few years, allegedly.
There is no way this is a meaningful- if even honest- attempt to explain the past.
By the way, what is happening in Indonesia is a massive mountain building exercise.
And, as others have pointed out, calling Venus a ‘runaway greenhouse’ is a deceptive way to speak of Venus. And anyone asserting Earth could become Venus is being even more deceptive.
Stephen Skinner says:
“Also, 5000ppm although larger than 400ppm is still not significant compared to 965,000ppm. as on Venus. If CO2 is that effective that small variations of between 300ppm to 5000ppm can have large temperature effects then 965,000ppm should have turned the surface of Venus molten?”
Actually it is much worse than that. It isn’t the proportion but rather the total amount of CO2 that matters. Counted in “terran ppm” the amount of CO2 in Venus atmosphere is more than 65,000,000 ppm.
Stephen Skinner says:
June 12, 2014 at 12:28 am
“Can it go any slower?”
Apparently it is slowing down. Can’t find the link, but there was a rash of stories a few months ago about measurements of Venus showing an unexpected change in its rotation.
One of those things.
Of course the difference between Venus and Earth is very simple: we have water. Without water our atmosphere would be a roiling, toxic nightmare just like the one on Venus, though we obviously wouldn’t be around to worry about it.
tty above,
The venusian atmosphere is under continual compression. It is not stratified and isothermal but under continued convectgion. Surface winds are monumental.
The atmosphere is so thick it is debatable if any insolation actually makes the surface to heat it. It is all adiabatic.
Actually it is pretty meaningless trying to quantify weathering of past mountain chains, the reason being that today only the roots of the mountains are left, and we have no good way of judging how high they were. It is possible to roughly judge the amount of weathering by studying the amount of sediments laid down around the mountains. However on that score the Caledonian orogeny was a great deal larger than the Variscan, judging by the vast deposits of “old red sandstone” and equivalent sediments.
Also the balance of mechanical erosion vs. chemical weathering varies widely. Young and steep mountain chains are largely mechanically eroded, and the sediments contain quite fresh, unweathered materials. The chemical weathering becomes dominant later, when the mountains are already partly eroded and there is plenty of finer materials to weather (a big, solid lump of rock weathers vastly slower than gravel).
Robertvd says: June 12, 2014 at 12:25 am
Venus is a newcomer in the solar system and it is slowly cooling down and speeding down its rotation velocity…
Stephen Skinner says: June 12, 2014 at 12:28 am
“… and speeding down its rotation velocity. ”
Can it go any slower?
Good question. Is retrograde slower than zero?
johnmarshall says: June 12, 2014 at 1:36 am
Venus, tropopause 70K above the surface, surface atmospheric pressure 92bar, insolation less than half that of earth due to very high albedo, (0.67) atmospheric lapse rate 10.2C/km surface temperature over 700K due to ADIABATIC COMPRESSION.
We had a post many years ago discussing the proposition that adiabatic compression was responsible for the high Venusian surface temperature, but one or two wise and learned commenters (the usual ones, as I recall) made well-reasoned and convincing arguments that adiabatic compression was not involved. The fact that the atmosphered rocky bodies in the solar system, Venus, Earth, Mars, and Titan, all fit the adiabatic temperature prediction was doubtless coincidence.
A runaway greenhouse involving positive CO2 feedback has the temperature going up to boil away all the oceans, and the water vapor getting dissociated up at the top of the atmosphere and losing the hydrogen to space. Trouble is, that doesn’t fit Venus. We have darn little evidence there ever was liquid water on Venus. No ocean basins, no water erosive features, maybe some deuterium in the atmosphere that could have been dumped by the same comets we suspect doused Earth, but nothing otherwise.
The temperature at the 1 bar level in Venus’ 96.5% CO2 atmosphere runs just under the boiling point, and is right about where our 0.04% CO2 atmosphere would be were we in Venus’s orbit. Move along, nothing to see here.
The most interesting thing to me about Venus’ atmosphere is that at that temperature and pressure, the CO2 is a supercritical fluid, where the density of liquid and gas are the same. That density is pretty impressive, too. Air runs about 2½ pounds per cubic meter, but on Venus, the CO2 runs 147 pounds.
supercritical fluid video
Johnmarshall says:
” The venusian atmosphere is under continual compression. It is not stratified and isothermal but under continued convectgion. Surface winds are monumental.
The atmosphere is so thick it is debatable if any insolation actually makes the surface to heat it. It is all adiabatic.”
It is under constant and unchanging compression. It is not being compressed to a smaller volume which is required for compressional heating.
“Surface winds are monumental”
Not according to the few probes that have landed there. They found virtually calm conditions. The strong winds are at high altitudes.
“The atmosphere is so thick it is debatable if any insolation actually makes the surface to heat it.”
In that case how come it was possible for the Venera probes to photograph their surroundings? The light level was fairly low, but it wasn’t dark.
“It is not stratified and isothermal but under continued convectgion.”
Indeed. And the convection is driven by what, if not solar heating? Geothermal heat?
“It is all adiabatic”
No atmosphere is “all adiabatic”. There is the sun on one side, the ground below and space all around you know.
MikwMCmillan says:
“The fact that the atmosphered rocky bodies in the solar system, Venus, Earth, Mars, and Titan, all fit the adiabatic temperature prediction was doubtless coincidence.”
No coincidence there. They are all convecting atmospheres which are expected to cool with altitude at the local adiabatic lapse rate (which depends on atmospheric composition). Incidentally this breaks down on Mars when there are global dust storms. Then the higher layers are warmer due to solar heating of the dust and low insolation at ground level.
Is this the solution the greens have been looking for – build more mountains?
So there are actually three differing opinions-
1- The Team has one opinion, but the science is not quite settled as yet.
2. We have the ‘Model’, that was tuned by the “team” to present the required outcome.
3. Then we have reality. That is the main problem apparently. That reality thing always appears to be way too stubborn to bend to the wishes of the Soothsayers, the bone-pointers and Magic-oil merchants.
Coincidentally, just yesterday I posted the following on the Tips and Notes page:
* * * * * *
Is it time to revisit the ‘runaway warming’ hypothesis for Venus’s atmosphere? It’s getting bandied about again, e.g.:
From here: http://www.dailygalaxy.com/my_weblog/2014/06/-venus-and-mars-hold-priceless-climate-change-warnings-for-earth-todays-most-popular.html
Grinspoon is a real scientist, so should be taken seriously. But can “current climate models . . . reproduce [Venus’s] temperature structure well”? Why does Venus have a much denser atmosphere than Earth does?
* * * * *
That question seems to me key. Venus’s gravity is only about 90% of Earth’s, so that can’t be the explanation for the incredibly dense atmosphere. The common assumption is that Venus and Earth began similarly, but Venus suffered runaway ‘global warming’, boiling off its water, while Earth didn’t. That doesn’t account for the atmospheric density. I wonder if, instead, perhaps Earth was like Venus is today, with a CO2/nitrogen atmosphere, but being farther from the Sun was able to retain water as it rained down in the form of comets. Then perhaps the new oceans and even newer plants sucked up the CO2, leaving a much thinner atmosphere. . .
What evidence do you have that Venus is “a newcomer in the solar system”? Velikovsky of course proposed that the Greek myth of the goddess Venus springing from Jupiter’s forehead was in fact a description of what the ancients observed in the sky: a new planet ejected from the giant Jupiter. This speculation was roundly rejected by astronomers, but Velikovsky did successfully predict that Venus would be very hot, and have hydrocarbons in its atmosphere (at a time when science-fiction stories about Venus, following the astronomers, assumed its clouds were H2O and its surface a tropical jungle).
/Mr Lynn
[Mods: Post seems to have vanished into the aether. Only one link in it, and WP says “Looks like you’ve already said that!” But maybe it’s in your Spam trap. Thx. /Mr L]
Why didn’t Earth develop an atmosphere like the one on Venus? :-
1. Venus (like Mars) does not have a strong magnetic core. Therefore there aren’t any extensive magnetic fields to help protect the planet. Apparently, gases like hydrogen, helium, and oxygen ions, would have been swept away by the solar wind, leaving the higher-mass molecules like carbon dioxide. (“Venus as a more Earth-like planet”, _Nature_ 450, Nov. 2007.)
2. Venus was left with a very dense atmosphere. It is more than 96% carbon dioxide.
3. The atmosphere’s pressure at the surface is 92 times more than Earth’s pressure.
4. Venus is considerably closer to the Sun, at about 0.72 of the distance from the Sun to the Earth.
5. The equator rotates at 6.5 km/h or 4 mph. (The Earth’s is about 1,670 km/h or 1,040 mph). Therefore a Venus day is *very long! Venus takes 243 Earth days to rotate once.
6. Naturally given the above, Venus does not have biomass (or oceans) to absorb some of the CO2, and it does not have a carbon cycle to lock carbon back into the rocks.
“tty says:
June 12, 2014 at 3:46 am
MikwMCmillan says:
“The fact that the atmosphered rocky bodies in the solar system, Venus, Earth, Mars, and Titan, all fit the adiabatic temperature prediction was doubtless coincidence.”
No coincidence there. They are all convecting atmospheres which are expected to cool with altitude at the local adiabatic lapse rate (which depends on atmospheric composition). Incidentally this breaks down on Mars when there are global dust storms. Then the higher layers are warmer due to solar heating of the dust and low insolation at ground level.”
They only cool at the adiabetic lapse rate if there when greenhouse gases radiate away their heat. With NO greenhouse gases, temperatures would ultimately stabilize at a constant temperature all the way up.
Robert G Brown posted here earlier on that very subject.
http://wattsupwiththat.com/2012/01/24/refutation-of-stable-thermal-equilibrium-lapse-rates/
There’s nothing preventing temperature inversions, as in your Mars referrals. It happens all the time on Earth, too, early in the mroning, as the ground radiates away heat faster than the atmosphere radiates away heat.
It seems that skeptics and alarmists agree (97%?) that a doubling of CO2 will increase temperature. For us to insist that is not true is unsupported. Where we disagree is in feed backs ….are the positive, negative, or on the whole balance out. If we hind cast the prob .7C rise since 1850 based on estimated ppm’s, feed backs seem to show neutral to negative…. Which of course is the case in most long term systems. Runaway temp based on carbon alone would seem to be unsupportable.
So when we argue with a warmer we often are talking past each other with a different view of the problem
[This is a repeat, as the comment seems lost. If it duplicates, please delete one.]
Coincidentally, just yesterday I posted the following on the Tips and Notes page:
* * * * * *
Is it time to revisit the ‘runaway warming’ hypothesis for Venus’s atmosphere? It’s getting bandied about again, e.g.:
From here: http://www.dailygalaxy.com/my_weblog/2014/06/-venus-and-mars-hold-priceless-climate-change-warnings-for-earth-todays-most-popular.html
Grinspoon is a real scientist, so should be taken seriously. But can “current climate models . . . reproduce [Venus’s] temperature structure well”? Why does Venus have a much denser atmosphere than Earth does?
* * * * *
That question seems to me key. Venus’s gravity is only about 90% of Earth’s, so that can’t be the explanation for the incredibly dense atmosphere. The common assumption is that Venus and Earth began similarly, but Venus suffered runaway ‘global warming’, boiling off its water, while Earth didn’t. That doesn’t account for the atmospheric density. I wonder if, instead, perhaps Earth was like Venus is today, with a CO2/nitrogen atmosphere, but being farther from the Sun was able to retain water as it rained down in the form of comets. Then perhaps the new oceans and even newer plants sucked up the CO2, leaving a much thinner atmosphere. . .
What evidence do you have that Venus is “a newcomer in the solar system”? Velikovsky of course proposed that the Greek myth of the goddess Venus springing from Jupiter’s forehead was in fact a description of what the ancients observed in the sky: a new planet ejected from the giant Jupiter. This speculation was roundly rejected by astronomers, but Velikovsky did successfully predict that Venus would be very hot, and have hydrocarbons in its atmosphere (at a time when science-fiction stories about Venus, following the astronomers, assumed its clouds were H2O and its surface a tropical jungle).
/Mr Lynn
I’m speechless. “Newcomer to the solar system”? “Slowly cooling down?” “Speeding down its rotation velocity?”
No, no, no, no, no. No. And no.
Just because Velikovsky smoked crack cocaine laced with LSD and peyote before writing his science fiction novels disguised as “true fact” doesn’t mean that you have to. Oh. My. God. Next you’ll tell me that Joseph Smith (dum-dum-dum), America’s first science fiction author, really did find golden tablets buried in upstate New York that he magically translated into a True Story of white-skinned Jews battling dark-skinned descendants of Cain with steel swords after navigating to the New World with magnetic compasses, or that we are all thetans murdered with hydrogen bombs 75 million years ago by a mean old dude named Xenu, forcing our thetan consciousnesses to inhabit the bodies of nearby T. Rexes and Velociraptors (another strangely popular science fiction story from the last century).
I give up. It really is true. Isaac Newton lived in vain. George Boole too. How is it possible to grow to adulthood without ever developing even a smidgen of common sense?
Please, please, please never ever state this in public again, especially if you are trying to “represent” the scientific challenge to the hypothesis of catastrophic climate change. You’ll force me to change sides, because the hypothesis of catastrophic runaway warming, ill-supported by evidence as it is, is still far, far sounder than the notion that a planet in a comparatively circular orbit in the normal ecliptic plane around the Sun “recently” arrived there and is in any particularly meaningful sense “still slowing down”.
rgb
The plot of CO2 over the last 600My is an inverse plot of the Abundance-of-Life on Earth. It was the proliferation of life that took the atmospheric CO2 down. Extinction events allowed it to rise; but that very same rise stimulated subsequent huge surges in life bringing it back down. Today the planet is life-rich at the limit of the available CO2. And more CO2 will give rise to yet more life.
So now melting alpine glaciers is a good thing?
Prior to the advent of green algae, CO2 levels were close to 100%. And somehow life survived and we didn’t get stuck in a run away greenhouse.
OK, here is a moderately interesting screen-scraped figure I cobbled together. I took the figure above showing atmospheric CO_2 and superimposed the curve showing global average temperature as inferred from the O18 proxy here:
http://upload.wikimedia.org/wikipedia/commons/9/9c/Phanerozoic_Climate_Change.png
Note that there is no attempt to map O18 to actual global temperature, but we can get at least some idea of how the map proceeds by considering the mean temperature in the current glaciation vs temperatures when Antarctica was ice free (suggesting that the temperature range from the peaks to the troughs of O18 is between 10 and 20 C, where on geological time the Earth is as cold as it has ever been since the Ordovician-Silurian glaciation 450 million years ago.
Here is the figure, where I literally traced the Phanerozoic curves and popped them on top of the figure above, scaling them so that their time scales corresponded. The grey bars are glacial epochs, the first one to the left is the O-S glaciation.
Combined CO_2 ppm and Phanerozoic O18 concentration
The figure kinda speaks for itself. It is this blatant disregard for what should be “common knowledge” to anyone publishing in climate science that really annoys me. How can you write a whole paper even weakly asserting that CO_2 variation caused mass extinctions by changing the climate without correlating the CO_2 concentration with the actual changes in the climate inferable from a far better proxy than “mass extinctions are sometimes caused by climate change”? How is it that no referee caught this omission? I don’t know about any of you, but I don’t see the slightest degree of correlation between CO_2 concentration and global average temperature.
Indeed, I would assert that this figure is absolutely, positively incompatible with the assertions that a CO_2 of 600 ppm implies any sort of climate change at all compared to the present. The Ordovician-Silurian glaciation occurred with mean CO_2 levels of ballpark 4000 ppm, sustained. Temperatures soared in mid-Permian with atmospheric CO_2 about where it is today, sustained (all of these peaks are tens of millions of years wide or wider — the entire industrial CO_2 increase plus its “catastrophic” projection isn’t even noise on the timescales involved). The oceans evolved sea life with shells with atmospheric CO_2 five to ten times what it is today. CO_2 in the entire era of the dinosaurs was order of 2000 ppm (5x present) and yet another weaker glacial era occurred across this time frame.
The only thing one can actually say with any degree of confidence from this replotting is this: CO_2 levels have, on a very coarse grained average basis, steadily decreased over the last 600 million years. At the same time, the Earth has undergone a cycle of heating and cooling that is almost completely flat when averaged in exactly the same way. You don’t need a calculator to eyeball nearly neutral planetary climate over the last 600 million years. Yes, that climate has ice ages and hothouse ages that last tens of millions of years. No, we cannot explain it. But the hypothesis that CO_2 is even a contributing cause fails to explain even the first order gross features of the variation. CO_2 has been falling at the rate of almost 1000 ppm/100 million years for 600 million years (eyeballing a linear regression of the data). Average global temperature hasn’t changed at all, for 600 million years (eyeballing a linear regression of the data).
And that, my friends, is something that I never seem to hear climate scientists acknowledge or discuss. Surely if CO_2 is the universal climate hammer, it would explain the primary variability of the data. Instead, if one attempts to cross-correlate the two curves in this plot (via, e.g. Kolmogorov-Smirnov) to see if there is any vague possibility that one is explanatory of the other, well, most statisticians wouldn’t even bother. The effect CO_2 is supposed to have isn’t subtle, and the eye does not lie. If there is any correlation whatsoever in there, it is “subtle” to say the very least.
rgb
(p.s. — Mod, please help me embed this figure, or tell me how to do it myself, as I’ve had no luck with embedded graphics so far.)
@Peter:
I found your “life” battery thought interesting. However, not all life is dependent on CO2, just most of the “macro” life forms that we, as very large human creatures, encounter in day-to-day existence. It is unlikely that “life” on Earth will acutally become entirely extinct until our local star starts shedding its outer layers and expands nearly to Earth’s orbit. Humans will probably not exist that long, geologically speaking, on Earth. Humans are too large a creature to survive the ever changing Earth over geological time. It’s useful to remember that there are more extinct species then living species of life, and that nearly all species larger than a few inches across have become extinct throughout Earth’s existence.
Thanks for taking the time to comment.
To the best of my, admittedly deficient, knowledge all life on Earth is carbon based, dependent upon carbon, hence organic chemistry where the properties of the carbon atom, in conjunction with oxygen, hydrogen etc allow for a bewildering array of organic molecules and compounds etc., thereby allowing life.
I suspect that the carbon needs of primitive aerobic and anaerobic life are relatively meager and will probably always be met by Earth’s geologic processes, at least until such times as the Sun has other plans.
What occurs to me, and this is where I hope more knowledgable minds will contribute, is that if the reduction of CO2 continues, as it appears to have done over the deep history of Earth, we will eventually reach a point or threshold where the more complex forms of plant life will struggle to exist on land. Obviously this then affects all those organisms which rely on vegetation, in one form or another, for their continued survival.
In discussions relating to the so called Fermi Paradox, there is often mention of “the Great Filter”, something that prevents life from attaining a sufficiently advanced biological/technological state such that it can advertise its presence to the universe at large. This is where my idea of CO2 (or rather the lack of it) being one such filter comes into play, the idea being that the path to intelligent life takes so long that CO2 reserves of the planet/atmosphere system are depleted to the point where such life is untenable. Hence the “flat” battery.
It seems to me that CO2 is not the poisonous pollutant portrayed in the media etc. but rather, the”Gas of Life”. But hey, what do I know, I’m only a humble tattoo artist.
All life was in the oceans back then, Mark.
When plants colonized the above water line land, the planet’s atmosphere was already filled with goodly amounts of oxygen thanks to the single celled creatures practicing photosynthesis. Then plants grew out of control due to lack of predators back then adding to the oxygen levels and suddenly eating a lot of the CO2 which is lucky for us for we are plant predators and need this CO2 for plants to grow faster so we can eat them. 🙂
“latecommer2014 says:
June 12, 2014 at 5:30 am
It seems that skeptics and alarmists agree (97%?) that a doubling of CO2 will increase temperature. For us to insist that is not true is unsupported.”
AGAIN, those making the claim of doubling CO2 causing temperature rise need to prove and support THEIR CASE first. They could start with the RGB post above.
Bill Illis says: June 11, 2014 at 9:22 pm
They got the timing completely backwards here.
Have to agree Bill:
http://i55.tinypic.com/11awzg8.jpg
My goodness, what an emotional response! I don’t know whether Robertvd had Velikovsky in mind when he said “Venus is a newcomer in the solar system,” but that’s the only author I know who has ever suggested such a thing. Certainly Velikovsky’s attempts to reconstruct the history of the Solar System from correspondences in ancient mythologies seldom rise beyond interesting speculation, and much of it seems physically impossible, but he was prescient at times—as for example disputing the dogmatic consensus of geological uniformitarianism (not unlike the AGW ‘consensus’ today). Nor do I know that he ever indulged in drugs—that seems an unwarranted calumny.
Perhaps Robertvd will tell us where he got the “newcomer” idea, and what evidence he has for it, if any.
/Mr Lynn
Yes, this is basically the same figure as that above, but if you link it here:
http://commons.wikimedia.org/wiki/File:Phanerozoic_Carbon_Dioxide.png
it gives you the references. The (Ward) figure above is not included, but if it were it would closely correspond to geocarb, copse and the compilation. Rothman is odd man out, it is the only one that has the right shape to be a plausible link between CO_2 and the global average temperature, as it asserts that CO_2 has almost never reached 1000 ppm. It still has CO_2 over 600 ppm at the O-S glaciation, though, and has it peaking around 1000 ppm around the Permian and Jurassic glaciation IIRC the dates correctly. Indeed, it might (if correct, note that apparently everybody else from multiple data sources disagrees, which doesn’t make him wrong but might make him probably wrong pending an explanation) even count as evidence that high CO_2 causes glacial epochs, except that there is far too much confounding evidence even for that.
Unless Rothman is right and everybody else is wrong, though, there is little to no reason to think that CO_2 concentration has been well correlated with global average temperature across geological time, as it has a relative variation of concentration of perhaps 10 to 15 (maximum minus minimum divided by minimum) with a strong temporal linear trend compared to a relative variation of global average temperature of around 0.05 (maximum minus minimum divided by minimum in degrees K) and is almost trendless (if anything, it exhibits a weak positive slope, but too weak to be considered significant I think). That is, the magnitude of the strongly negatively trended variation in CO_2 is over two orders of magnitude larger than the scale of the 30+ My variations in global average temperature around a weakly positive trend.
Not exactly the story that is being told by the climate models. Indeed, I expect that if one loaded 5000 ppm CO_2 into any of the current climate models, they would produce the Ordovician-Silurian glacial epoch 0.00000000000001% of the time, and only then because somebody mis-entered data or the computer’s CPU was hit by a cosmic ray at just the wrong time that flipped a couple of bits in the CO_2 concentration register.
Which is why they are badly, badly wrong, of course. With the physics they’ve got, glaciation in over 1000 ppm CO_2 is just flat impossible no matter what confounding variables you throw in (well, maybe things like the Siberian Traps or Yellowstone could produce it if one sets aerosols but NOT particulates through the roof, but we’re well and away from having that kind of utility in our computational models and besides, we just don’t have the data to even properly explore the possibilites).
Again, climate may not be (accurately) computable. There are lots of problems that aren’t computable, and a lot of those problems “look like” climate models in terms of complexity. It isn’t really even surprising.
rgb
He continued, “We believe that it is this which led to the dramatic drop in atmospheric levels of CO2. We estimate that if it hadn’t been for the formation of the Hercynian mountains, the atmospheric CO2 levels would have reached around 25 times the pre-industrial level, meaning that CO2 levels would have reached around 7000 ppm (parts per million).
On a graph with the time scale of 600 to 0 Million Years how well can you show ‘dramatic’ or is their definition very different than everyone else’s?
Hercynian Mtns were build in late Devonian, after CO2 had already declined from 5000ppmv to about half that. So was it earlier mountain building that ate up that CO2? Also, the CO2 didn’t decline from mtn building after the late devonian, it declined because the Dev. was followed by the Carboniferous – gee what an interesting term – the period when almost all the coal on earth was formed from the massive growth of swamps with 300ft high trees that, when they died out, formed coal measures. Low humidity- bollocks- these these giant forests grew in a very humid, rainy environment. I haven’t had time to read previous posts but someone has surely pointed this out.
rgbatduke says:
June 12, 2014 at 7:21 am
IMO temperatures as cold as now occurred during the Carboniferous-Permian glaciation as well as the Ordovician-Silurian, which lasted less time than the C-P or present Icehouse. The Jurassic-Cretaceous glaciation was much less severe. Icehouses occur at about 150 million year intervals, which is one of the observations supporting Shaviv & other cosmoclimatology proponents.
Speaking of GCMs & the past, the Cretaceous is a huge problem for the models. To get a world as warm & equable as the mid-Cretaceous with its estimated level of CO2 the models need ECS of at least six to work.
When the climate people start in on venus, that’s when I know they are totally out of their league. Most about venus has already been hit in this thread but I don’t think all that many folks really get the ramifications. Earth and Venus are about the same size and are rocky planets and they share the same corner of the solar system. That is the limit of their similarity. Outside of an unfortunate collision with a Mars sized object (another one – not the last one), Earth cannot become like venus. Venus has the atmospheric equivalent of roughly 92 Earth atmospheres, 90 of them pure co2 and the other two essentially nitrogen (like Earth’s minus the o2). In reality, the co2 is concentrated at the bottom, being much heavier than n2 and there being no significant rotational forces to help create weather or motion in the atmosphere. It is more like our water oceans than something like our atmosphere. The differences get far more substantial from there.
Planetary albedo is totally coming from the upper layers of clouds which reflect the vast majority of light from the Sun, which would be almost double what the Earth receives per unit area. For a simplistic radiation balance calculation like Earth’s which suggests about 255k would be its averaged temperature with no atmosphere, Venus would be more like 180K because there is very little light from the Sun being absorbed. The photos taken by the landers (Soviet Veneera craft from the 1970s) show a dull dreary place that is rather reddish with the color analysis. The cameras were likely near IR sensitive as well as visible light so it’s possible some of the scenery was lit by the glow of the hot surface atmosphere rather than by the dim diffuse remnants of sunlight making its way to the surface.
Were Venus to not have this massive co2 ocean – whose mass is about 1/2 that of Earth’s water oceans, and if Venus’ sky did not have totally cloud cover, it would be a disastrous place as high noon there would last for weeks, allowing the temperatures to rise unbelievably and doubtlessly creating massive amounts of air turbulence as we would have a hot area and a cold area slowly moving around the planet.
This ocean of co2 does have a massive effect on temperatures because it drastically slows down radiation energy transfer – especially under high pressures. However, the upper cloud cover that reflects most of the Suns incoming energy will also be blocking most of the upwelling IR from the surface anyway and since there is essentially no weather in the troposphere, just uniform temperature, there is very little convection either. Much of this heat may be the original formation energy or possibly a slightly more recent collision (that might be the reason why the rotation was slowed to near zero).
Note that Venus has no significant magnetic field. Such fields are associated with the rotation of the planet and the fact that at least part of the core is liquid. Earth has both and a nice protective magnetic field. Mars has similar rotation to Earth but evidently no molten core so it has no field. It would seem that Venus has a molten core available – but no rotation of consequence – and hence no magnetic field. There is some variation in atmospheric concentrations that have been detected which suggests that Venus still has volcanic activity going on. The radar imaging of the surface shows substantial volcanic activities have occurred sometime.
To claim or think that Venus could have been just like Earth before a runaway greenhouse effect happened is just total BS. The simple fact that the rotational speed of the planet is extremely low guts any possibility of that being the case. The presence of 90 atmospheres of co2 brings up the question of whether the Earth might ever have had that much and then disposed of it via geological processes.
Curiously, whenever I bring up Earth’s magnetic field, it is asserted as the reason it has an atmosphere at all, the claim being made that without it, the solar wind would strip the Earth of its atmosphere. Yet Venus has been around as long as the Earth unless/until proven otherwise, has NO magnetic field, is exposed to both more intense solar wind and to more intense sunlight, and yet it has an atmosphere with 92 times the surface pressure. True, CO_2 is more massive than e.g. O2 or N2, but not that much more massive — one would expect for the factor of 2+ in insolation and solar wind to more than compensate given geological time.
This leaves me a bit dubious about the magnetic field being critically protective of atmosphere. I rather suspect that the thing that thinned out the Earth’s atmosphere was the hypothetical but evidence supported collision with the proto-moon Theia, which probably blew off most of the atmosphere of both planets. As for the oceans, I hold no opinion — maybe cometary bombardment, maybe oxidized outgassing of elementary hydrogen in the original mix. There’s plenty of water to be had around the solar system — no shortage of hydrogen, not much shortage of oxygen. That doesn’t mean the magnetic field isn’t important, only that maybe it isn’t as important as people like to assert without any real possibility of doing an experiment to see if they are right.
rgb
Dear alarmists, work a model for this:
We have definitive proof that Venus and Earth were both identical in their original makeup. Both had oceans, clean air and abundant life. Unfortunately Venus evolved a parasite race. This parasite ravaged their world with their SUVs, sucking all the CO2 from the ground and pumping it into the air. As their world began to die, they built ships to transport them to their close neighbor. Fortunately the parasite lost their technology shortly after coming to Earth about 1MYA, but unfortunately redeveloped it. In the 1MY since, all evidence of life on Venus has disappeared, along with their oceans and cities, since the surface temperatures are hot enough to melt rock.
There, the perfect alarmist story. Now get busy modelling it so we can all know it’s true.
Thank You!
[my emphasis]
That’s what I was wondering—whether Earth and Venus started off with similar properties (thick, CO2+ atmospheres, maybe the result of heavy volcanism) and then diverged. Could it have been the putative collision with another body that created our Moon, which also tore off most of the atmosphere? If so, we’ve got that unknown planetoid to thank for our ‘Goldilocks’ planet. If the water on Earth came from outer space (comets), then it probably wouldn’t have survived the descent through a primordial Venus-like atmosphere.
Just speculation on my part. Is there evidence pro or con such a scenario? Links? I’d like to offer it vis-a-vis the apparent consensus (thanks, Carl Sagan) of “runaway global warming” on Venus.
/Mr Lynn
If you plotted a trend line of that CO2 graph above, you’ll see that it’s heading towards zero. Before it hits zero, plants and trees would start starving, I think the level is around 180 ppm
So in a sense, fossil fuels companies are replenishing plant and tree food back in the atmosphere and in the process, are prolonging life on Earth.
If there ever was a paper that demonstrated grant gravy train chasing, this one fits the description to a T. Ya know folks, when the cat is FINALLY let out of the bag and people all over the world wake up to the swindle, there will be hell to pay politically. And not even the innocent pigs at the trough will escape.
This business of Earth destroyed by runaway warming like Venus started with Hansen and his death trains. If we didn’t stop burning fossil fuels, he warned, this runaway warming would finish us up. The oceans would boil and the atmosphere would become like Venus, mostly hot carbon dioxide. Before he joined GISS he had been an astronomer on the Pioneer Venus project, even had an experiment going up there by spacecraft. But he abandoned that, quit NASA Pioneer project, and joined GISS. In three years he was boss. Combined with his sudden change of venue it looks to me like he was set up to change it into a global warming institution. You would think that someone who has been an astronomer on a Venus project would know something about Venusian geology but no luck – he was just ignorant. The difference between the Earth and Venus is that Venus has no plate tectonics. Radioactive heat from the interior of Earth is constantly vented by plate boundary volcanism. On Venus it just accumulates beneath the crust which eventually so weakens it that it breaks up into giant slabs that sink into the interior and a new crust is formed. From impact crater counts it has been estimated that the approximate time between such resurfacing events is from 300 to 600 million years. If Venus is the same age as Earth it has had time for perhaps as many as ten such makeovers by now. Its atmosphere is not formed by boiling oceans but a product of these giant eructations it periodically experiences.
L. E. Joiner says:
June 12, 2014 at 1:05 pm
The collision which formed the moon might have contributed to earth’s apparently unique form of plate tectonics. Venus was once highly volcanic, but now much less so. And we have the moon.
Earth’s atmosphere was at one time probably about as rich in CO2 as Mars’ or Venus’. It was however most likely never as dense as Venus’. The many differences between the two sister planets are so great that Hansen’s “Venus Express” is beyond laughable.
Please also bear in mind that the temperature of the Venusian atmosphere at the point where its pressure is around the same as at earth’s surface is also about equal. This despite the fact that it’s almost entirely composed of greenhouse gas & closer to the sun.
I’ve been maintaining a database of all CO2 estimates through time from all studies which make the data available and are not just cherrypicking one date or three dates but provide at least ten estimates over some period (there is a huge amount of cherrypicking in climate science and especially with respect to CO2 levels).
There are a few types which appear to be unreliable (producing unrealistically low estimates and unrealistically high ones that I have discarded).
So here is ALL of the 2,700 reliable estimates of CO2 over the last 750 million years. There is no point putting them on separate lines. They are all estimates of CO2 that are from different time periods anyway so just put them all together. I can break this down into tighter time-periods if someone wants.
http://s12.postimg.org/kuw5mqdst/CO2_LAST_750_Mys.png
The sources for this chart are all the estimates (excluding a few unreliable methods) from Berner GeoCarb III, Pagani 2005, Antarctic Ice Core Composite, Pagani 1999, Royer 2006 Composites, Pearson 2000, IPCC AR4 2007 – Royer 2008 Composites, Pearson 2009, Tripati 2009, Bao 2008, Hoenisch 2009, Beerling Royer 2011, Bartoli 2011, Seki 2010, Mcanena 2013
[Thank you. Request you add this comment to the CO2 reference page comments section. .mod]
This time period is completely foreign to the pro-AGW scientists. They do not know this is what the CO2 data from the last 40 million years shows.
http://s10.postimg.org/5fz8g5a3d/CO2_Last_40_Mys.png
Bill Illis says:
June 12, 2014 at 7:05 pm
How many estimates do you have for the Pre-Cambrian? Just eyeballing your graph, it appears that the highest CO2 level for the time period you’ve graphed was during the most extreme glaciation, the Cryogenian (hence the name!) Snowball Earth episode of the Marinoan.
http://en.wikipedia.org/wiki/Marinoan_glaciation#Cryogenian_Snowball_Earth
Thanks!
Bill Illis says:
June 12, 2014 at 7:12 pm
And consider what coincides with the big drop down at the Eocene/Oligocene boundary?
1) Recurrence of the 150 million year cosmoclimatological icehouse phase, with
2) Land over the southern polar regions, with
3) Antarctica isolated from other continents by deep ocean currents.
Compared with these “forcings”, CO2 is not a pimple on a penguin’s cloaca.
tty says
The probes that have landed there have landed in calm conditions.
Two probes have landed on Venus, both Russian. The first crashed and was crushed by the atmospheric pressure. No further contact. The second lasted for enough time to transmit one grainy red picture of a barren rocky surface and was then crushed. Surface wind estimates from onboard telemetry was of high winds. the second lander lasted only a few minutes so surface data was scant but very high temperatures, high pressure and high winds.
A couple of posts above give the impression that Venus had a different history to Earth. It did not. It formed at about the same time, with similar conditions, magma ocean etc. but differed in one very different way. For some reason it gained no water. Water is the key to a stable climate, it provides a thermostat to excessive heating because of the narrow band of liquidity of water and latent heat removal from the surface on evapouration. This vapour rises, cools, forms cloud which increases albedo so reducing heat reaching the surface.
Both planets had a similar atmosphere, very high in CO2 but without water there was no mechanism for changing this gas to oxygen. Earth’s proto atmosphere must have been well over 50% CO2 because all the oxygen in the atmosphere is from photosynthesized CO2. Given our 22% O2 atmosphere plus all the CO2 sequestered as limestone, the most common sedimentary rock, plus the O2 lost to oxidation of soluble iron in the oceans some 2Ga years ago adds up to vast masses of CO2. There were times when O2 levels were much higher than today given the mega insect life flying about a few hundred million years ago.
Water is the key.
@johnmarshall . 3:42am … “For some reason it gained no water.”
There are some possible reasons why Venus lost its water, .. if it had any.
_(Extracts from: #comment-1660646 . June 12, 2014 at 4:59 am.)_
1.. Venus (like Mars) does not have a strong magnetic core. Therefore there aren’t any extensive magnetic fields to help protect the planet. Apparently, gases like hydrogen, helium, and oxygen ions, would have been swept away by the solar wind, leaving the higher-mass molecules like carbon dioxide. (“Venus as a more Earth-like planet”, _Nature_ 450, Nov. 2007.)
2.. Venus was left with a very dense atmosphere. It is more than 96% carbon dioxide. The atmosphere’s pressure at the surface is 92 times more than Earth’s pressure.
3.. Venus is considerably closer to the Sun, at about 0.72 of the distance from the Sun to the Earth.
4.. The equator rotates at 6.5 km/h or 4 mph. (The Earth’s is about 1,670 km/h or 1,040 mph). Therefore a Venus day is *very long! Venus takes 243 Earth days to rotate once.
[ Billions of years ago there may have been liquid water at the surface, which would have evaporated into the atmosphere. (“Searching for Evidence of Past Oceans on Venus”. Bulletin of the American Astronomical Society 39: 540, Oct. 2007.) ]
“L. E. Joiner says:
June 12, 2014 at 1:05 pm
cba says:
June 12, 2014 at 11:39 am
. . . To claim or think that Venus could have been just like Earth before a runaway greenhouse effect happened is just total BS. The simple fact that the rotational speed of the planet is extremely low guts any possibility of that being the case. The presence of 90 atmospheres of co2 brings up the question of whether the Earth might ever have had that much and then disposed of it via geological processes.
[my emphasis]
That’s what I was wondering—whether Earth and Venus started off with similar properties (thick, CO2+ atmospheres, maybe the result of heavy volcanism) and then diverged. Could it have been the putative collision with another body that created our Moon, which also tore off most of the atmosphere? If so, we’ve got that unknown planetoid to thank for our ‘Goldilocks’ planet. If the water on Earth came from outer space (comets), then it probably wouldn’t have survived the descent through a primordial Venus-like atmosphere.
Just speculation on my part. Is there evidence pro or con such a scenario? Links? I’d like to offer it vis-a-vis the apparent consensus (thanks, Carl Sagan) of “runaway global warming” on Venus.
/Mr Lynn
”
General theories of the solar system formation indicate it was rather stratified by distance from the Sun at formation, then all the anomalies not explained (like Venus essentially not rotating and in retrograde) get explained by catastrophes. It would seem that both Venus and Earth had major catastrophes early on and Mars which is much smaller managed to get a big gash in it. Mercury again is way too small for an atmosphere. These are our four terrestrial planet examples we have to work with. Mercury too had a minor major catastrophe – an impact affecting the far side of the planet and creating weird terrain.
The generally accepted Moon formation theory was an object around the size of Mars struck the young Earth. Material was blown off that formed the Moon and apparently the object was absorbed. The absence of rotation of Venus can be explained by an impact as well. Note there is still a solar system problem of what happened to all that angular momentum that should be present from the formation.
Neither Venus nor Mars has any significant magnetic field and Mars has only a tiny fraction of Earth’s atmosphere, almost all co2. Absence of magnetic field and small size might explain the loss of a serious atmosphere and there is evidence to suggest liquid water existed in substantial amounts at one time. Water from comet impacts makes sense as it would seem water needed to come from further out.
Earth’s current atmosphere is evidently its second one. Oxygen was freed up early on by biological activity. It is known there is a great deal of co2 present in rocks where it was captured via geological processes. I don’t recall seeing any theories or numbers suggesting that Earth had as much co2 as Venus has now though. Considering Mars also has a substantially co2 content in its atmosphere that is left, would suggest that since the Earth apparently formed between Venus and Mars, then it should have also mostly had co2 making up the initial atmosphere. Also, when we see volcanic eruptions, those two have lots of co2 coming back out from being trapped long ago. However, considering Venus has about the equivalent of two Earth atmospheres of nitrogen, it would seem that Venus may have had twice the total atmosphere of early Earth. It does not seem realistic that Earth which is further out than Venus and contains a substantial magnetic field would have lost atmosphere much faster than Venus.
That said, our two possibilities that come to mind are that Earth lost a substantial amount of atmosphere in collisions such as that which evidently formed the Moon or that it formed with perhaps half the atmosphere that Venus formed with or wound up with after a possible collision that stopped its rotation. I haven’t seen any numbers as to just how much co2 is actually trapped in rock by geological processes but it could be fairly substantial, very possibly a few atmospheres worth. Why Venus didn’t have the same thing happen might be related to too much atmosphere or no rotation. Also, Venus rotational axis is essentially perpendicular to the orbital plane – which suggests that it didn’t have a catastrophic collision.
With Jupiter (and the rest) along with Mars and Earth running interference, Venus should have had far fewer impacts from comets so much less water would have arrived. It would have become steam on the way down and there is evidence that despite its global ocean of co2, Venus does have impact craters as well as tremendous volcanic activity (at some point in time).
Your hypothesis is about as good as any other based on what is presently known (at least from what I can recall at the moment).
A note to some of the other posters here. It is likely that Earth and Venus formed rather similarly. However, it is very likely that water was not part of either early planets but rather that it arrived later in comet bombardments and with Venus closer in, Earth, Mars, Jupiter, etc were getting more hits so there were less comets available to impact Venus. Note too that in the last 20 yrs, there have been two observed major impacts on the surface of Jupiter and at least one was a full bore comet chock full of h2o.
milodonharlani says:
June 12, 2014 at 7:16 pm
—————————-
CO2 at 570 Mya 3,277ppm; 635 Mya 12,000 ppm; 750 Mya 4,500 ppm
Last two are from the last Snowball Earth episodes and many times smaller than what would have been required to lift the Earth out of these ice ages. So it wasn’t CO2 that ended the Snowballs.
Magnetic reversal leading to O2 depletion as explanation for some mass extinction events:
http://blogs.discovermagazine.com/d-brief/2014/06/10/earths-magnetic-flips-may-triggered-mass-extinctions/#.U5szDEAXJLr
Alan McIntire says: June 12, 2014 at 5:07 am
…With NO greenhouse gases, temperatures would ultimately stabilize at a constant temperature all the way up.
No, it’s the total energy that evens out all the way up. With gravity included, what the higher molecules gain in potential energy, they give up in temperature.
Alan McIntire says:
“With NO greenhouse gases, temperatures would ultimately stabilize at a constant temperature all the way up.”
No they wouldn’t. This is a popular myth, probably due to the climate scientists’ obsession with radiative transfer and general ignorance of basic physics. Heat would still be transferred by conduction between ground and the atmosphere, and differences in ground temperatures would inevitably result in convection (at the dry adiabatic lapse rate). The convection would be weaker and shallower than in an atmosphere with GHG’s, but the atmosphere would never become isothermal (unless the planet was irradiated equally from all directions and had a completely homogenous surface).
The whole argument is theoretical in any case. It being extremely unlikely that there is a planet anywhere without GHG’s in the astmosphere.
tty.
the most powerful heat loss process in any atmosphere is convection. radiation is a very poor third. To convect there only need be a temperature difference from the surface. GHG’s make no difference to convection only to conduction/radiation. There can never be an isothermal atmospheric profile because gravity will still do work on it which heats it up. It also contributes to lapse rate.
tty
Jupiter has an atmosphere of Hydrogen and Helium. Neither are GHG’s but Jupiter radiates more heat than the Earth, in excess of 300W/m2, because the atmosphere heats itself by adiabatic compression.
I don’t buy it. First of all, why O_2? N_2 is lighter and more easily stripped. Second when they say oxygen dropped by 9%, I assume they mean 9% relative, not absolute, as it is unlikely the earth could have recovered from a drop of 9% absolute. 9% relative is less than 2% absolute, varying from 20% of the atmosphere to 18% of the atmosphere. This wouldn’t kill a flea. Available oxygen varies by more than that when you walk up a not-particularly-tall mountain. Third, there is no particularly good reason to think that pole reversal is the cause of the O_2 depletion. A far simpler explanation, and one with direct evidentiary support, is that the roughly 1% to 2% CO_2 concentration in the atmosphere ate 1% to 2% of the O_2 (note that it is carbon plus O_2!). It wasn’t “stripped” by solar wind, it was bound up in carbon dioxide, and in spite of this the Earth was in an icehouse phase, not a greenhouse phase. Note the following combined graph:
http://www.phy.duke.edu/~rgb/combined.png
The CO_2 data is consistent with large meta-analyses of multiple proxies for CO_2 from at least four or five major independent studies, and is probably correct. Observe that if this data is correct, then the “9% relative depletion” is almost perfectly explained by CO_2, which was around 2% at the time. Note also that (again) “icehouse earth” phases with 2% CO_2 are virtually impossible to explain within the confines of the existing models. Not one of them allows for a persistent glacial era with this level of CO_2, and yet the Earth’s historical record, in geological time, is rife with glacial epochs occurring with high CO_2. Not “high” like 400 ppm, but “high” like 4000 ppm, 2000 ppm, and the like.
rgb
Gravity does not “do work on it” unless the atmosphere is actively collapsing, permanently, to a lower energy state. In the case of Jupiter it is remotely possible that heat is being released from its original collapse, although there are alternative explanations and [we] lack any good way of performing measurements to choose between them, so far. On Earth or other old, smaller planets with thin (as in thickness, not density) atmospheres surrounding rocky balls, gravity is no longer doing any net work on the atmospheres at all — they are in isostasis and gravity is a conservative force.
You keep making this sort of statement on WUWT, and it continues to directly violate the laws of energy conservation. When you assert that “gravity will still do work on it which heats it up” you are simply betraying a deep ignorance of the laws of physics. Gravity, on the other hand, does indeed contribute to the adiabatic lapse rate.