From the University of Colorado at Boulder a claim that computer modeling has solved the problem, with an atmosphere that is 20,000 parts per million of CO2 and 1,000 ppm of methane.
CU study shows how early Earth kept warm enough to support life
Scientists tackle faint young sun paradox with 3-D climate models
Solving the “faint young sun paradox” — explaining how early Earth was warm and habitable for life beginning more than 3 billion years ago even though the sun was 20 percent dimmer than today — may not be as difficult as believed, says a new University of Colorado Boulder study.
In fact, two CU-Boulder researchers say all that may have been required to sustain liquid water and primitive life on Earth during the Archean eon 2.8 billion years ago were reasonable atmospheric carbon dioxide amounts believed to be present at the time and perhaps a dash of methane. The key to the solution was the use of sophisticated three-dimensional climate models that were run for thousands of hours on CU’s Janus supercomputer, rather than crude, one-dimensional models used by almost all scientists attempting to solve the paradox, said doctoral student Eric Wolf, lead study author.
“It’s really not that hard in a three-dimensional climate model to get average surface temperatures during the Archean that are in fact moderate,” said Wolf, a doctoral student in CU-Boulder’s atmospheric and oceanic sciences department. “Our models indicate the Archean climate may have been similar to our present climate, perhaps a little cooler. Even if Earth was sliding in and out of glacial periods back then, there still would have been a large amount of liquid water in equatorial regions, just like today.”
Evolutionary biologists believe life arose on Earth as simple cells roughly 3.5 billion years ago, about a billion years after the planet is thought to have formed. Scientists have speculated the first life may have evolved in shallow tide pools, freshwater ponds, freshwater or deep-sea hydrothermal vents, or even arrived on objects from space.
A cover article by Wolf and Professor Brian Toon on the topic appears in the July issue of Astrobiology. The study was funded by two NASA grants and by the National Science Foundation, which supports CU-Boulder’s Janus supercomputer used for the study.
Scientists have been trying to solve the faint young sun paradox since 1972, when Cornell University scientist Carl Sagan — Toon’s doctoral adviser at the time — and colleague George Mullen broached the subject. Since then there have been many studies using 1-D climate models to try to solve the faint young sun paradox — with results ranging from a hot, tropical Earth to a “snowball Earth” with runaway glaciation — none of which have conclusively resolved the problem.
“In our opinion, the one-dimensional models of early Earth created by scientists to solve this paradox are too simple — they are essentially taking the early Earth and reducing it to a single column atmospheric profile,” said Toon. “One-dimensional models are simply too crude to give an accurate picture.”
Wolf and Toon used a general circulation model known as the Community Atmospheric Model version 3.0 developed by the National Center for Atmospheric Research in Boulder and which contains 3-D atmosphere, ocean, land, cloud and sea ice components. The two researchers also “tuned up” the model with a sophisticated radiative transfer component that allowed for the absorption, emission and scattering of solar energy and an accurate calculation of the greenhouse effect for the unusual atmosphere of early Earth, where there was no oxygen and no ozone, but lots of CO2 and possibly methane.
The simplest solution to the faint sun paradox, which duplicates Earth’s present climate, involves maintaining roughly 20,000 parts per million of the greenhouse gas CO2 and 1,000 ppm of methane in the ancient atmosphere some 2.8 billion years ago, said Wolf. While that may seem like a lot compared to today’s 400 ppm of CO2 in the atmosphere, geological studies of ancient soil samples support the idea that CO2 likely could have been that high during that time period. Methane is considered to be at least 20 times more powerful as a greenhouse gas than CO2 and could have played a significant role in warming the early Earth as well, said the CU researchers.
There are other reasons to believe that CO2 was much higher in the Archean, said Toon, who along with Wolf is associated with CU’s Laboratory for Atmospheric and Space Physics. The continental area of Earth was smaller back then so there was less weathering of the land and a lower release of minerals to the oceans. As a result there was a smaller conversion of CO2 to limestone in the ocean. Likewise, there were no “rooted” land plants in the Archean, which could have accelerated the weathering of the soils and indirectly lowered the atmospheric abundance of CO2, Toon said.
Another solution to achieving a habitable but slightly cooler climate under the faint sun conditions is for the Archean atmosphere to have contained roughly 15,000 to 20,000 ppm of CO2 and no methane, said Wolf. “Our results indicate that a weak version of the faint young sun paradox, requiring only that some portion of the planet’s surface maintain liquid water, may be resolved with moderate greenhouse gas inventories,” the authors wrote in Astrobiology.
“Even if half of Earth’s surface was below freezing back in the Archean and half was above freezing, it still would have constituted a habitable planet since at least 50 percent of the ocean would have remained open,” said Wolf. “Most scientists have not considered that there might have been a middle ground for the climate of the Archean.
“The leap from one-dimensional to three-dimensional models is an important step,” said Wolf. “Clouds and sea ice are critical factors in determining climate, but the one-dimensional models completely ignore them.”
Has the faint young sun paradox finally been solved? “I don’t want to be presumptuous here,” said Wolf. “But we show that the paradox is definitely not as challenging as was believed over the past 40 years. While we can’t say definitively what the atmosphere looked like back then without more geological evidence, it is certainly not a stretch at all with our model to get a warm early Earth that would have been hospitable to life.”
“The Janus supercomputer has been a tremendous addition to the campus, and this early Earth climate modeling project would have impossible without it,” said Toon. The researchers estimated the project required roughly 6,000 hours of supercomputer computation time, an effort equal to about 10 years on a home computer.
h/t to Dr. Leif Svalgaard
BioBob says:
July 10, 2013 at 11:30 am
But whenever you wish to discuss the role of life on earth,which likely involves the last 2 billion years or so, I will feel free to contribute
But then stick to relevant facts, not COAL, not limestone, not corals, ALL habitats, etc.. Every time your brilliance brings up some claim, I have in my ignorance shown it to be irrelevant. That is all.
Chad Wozniak says:
July 10, 2013 at 11:33 am
Tried-and-true practice is different, however, as you point out, but again this is experience rather than pure theory at work.
It only becomes tried-and-true practice once the theory has settled. e.g. Lasers, MRI, and GPS devices were not the result of experience, but of application of settled theory that works.
Stephen Rasey says (July 10, 2013 at 11:06 am): “They didn’t even mention atmospheric pressure. Musta slipped their minds.”
Oops. I seem to have misled you by selectively quoting the Methods section. Sorry, because later in Methods the authors write:
“Estimates of the late Archean surface pressure from fossilized raindrop imprints suggest that it was
probably not much different from today, though the authors leave open the possibility that pN2 could have been as much as twice [present] as an upper limit (Som et al., 2012).”
Also from Methods:
“Archean simulations assume a solar constant of 1093.6W [per square meter], which is 80% of the present-day value.”
I’m wondering if the higher extreme ultraviolet (XUV) level 3 billion years ago should be taken into consideration.
@Chad Wozniak – 11:40 am
“Rare Earth” is a prized book on my shelf. It’s thesis is profound. That life may be much more common then we previous thought, but complex life much more rare. In the past 30 years, we have found life in hostile environments: dark deep-sea volcanic vents, in ice, in rock, in hydrothermal pools. But complex life requires time and opportunity for evolution to do its magic. I recommend the book to anyone with an interest in science. It is a wonderful assimilation of astronomy, geology, geophysics, biology, physics, genetics, and chemistry. Fertile ground for thinking outside of the box of the present day.
See: WUWT Feb 28, 2013 Snowball Earth for more thoughts on Rare Earth conditions.
Leif. Still enjoying the lack of response. Is 110W of solar significant with the majority of that energy being entropically available within a 288K environment, as an example. Could 330W of long wave ever be considered similar?
Remember this is the ‘greenhouse’ energy budget’
DUH – Leif, you brought up the “irrelevance” by asking how limestone indicated photosynthesis. and the ultimate fate of glucose not me. I was just pointing out your inadequacies in that regard. rofl
In any case, my friend, we will never KNOW what actually occurred on earth 4 billion years ago until we can time-travel back in some manner. I find these speculations little more than “full of sound and fury, signifying nothing.”
So, they’re admitting 20,000 ppm in the atmosphere of an EPA declared pollutant is “hospitable to life”.
LOL
lsvalgaard says (July 10, 2013 at 10:51 am): “…Annual Review of Energy and the Environment, Vol. 24: 645-661, 1999”
Thanks again, Leif. That answered some of the questions I hadn’t even thought of. 🙂
nuwurld says:
July 10, 2013 at 12:28 pm
Leif. Still enjoying the lack of response. Is 110W of solar significant with the majority of that energy being entropically available within a 288K environment, as an example. Could 330W of long wave ever be considered similar?
Your ‘question’ is ill-posed and does not lend itself to an equally ill-defined answer. What are ‘significant’ and ‘similar’ in this regard?
biobob says:
July 10, 2013 at 12:31 pm
DUH – Leif, you brought up the “irrelevance” by asking how limestone indicated photosynthesis. and the ultimate fate of glucose not me.
My question was [obviously] concerned with conditions 3 billion years ago. All of your ‘responses’ were irrelevant for that question.
Inre: photosynthesis and limestone
The Foraminifera (“hole bearers”, or forams for short) are a phylum or class of amoeboid protists. They are characterized both by their thin pseudopodia that form an external net for catching food, and they usually have an external shell, or test, made of various materials and constructed in diverse forms. Most forams are aquatic, primarily marine, and the majority of species live on or within the seafloor sediment (benthos) with a small number of species known to be floaters in the water column at various depths (plankton). A few are known from freshwater or brackish conditions and some soil species have been identified through molecular analysis of small subunit ribosomal DNA.[1][2]
Foraminifera typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in structure.[3] These shells are commonly made of calcium carbonate (CaCO3) or agglutinated sediment particles. About 275,000 species are recognized, both living and fossil.[citation needed] They are usually less than 1 mm in size, but some are much larger, the largest species reaching up to 20 cm.[4]
…
Tests are known as fossils as far back as the Cambrian period,[18] and many marine sediments are composed primarily of them. For instance, the limestone that makes up the pyramids of Egypt is composed almost entirely of nummulitic benthic Foraminifera.[19] Production estimates indicate that reef Foraminifera annually generate approximately 43 million tons of calcium carbonate and thus play an essential role in the production of reef carbonates.[20]” ref: Wik
If the sun would have had the same output as today what should have been the distance to the sun to have the faint young sun paradox effect ? Why are we so sure the Earth always has had the same place in the solar system ?
Robertv says:
July 10, 2013 at 1:48 pm
Why are we so sure the Earth always has had the same place in the solar system ?
http://www.leif.org/EOS/1306-3166-Faint-Sun.pdf
@lsvalgaard –
Not to be picky about semantics, but the possibility remains, however remote it may seem, that any “settled” theory may eventually encounter a problem for which it does not work. The items which you describe that succeeded on the first attempt probably benefited from experience which ultimately did go back to tried-and-true at some point, and to existing knowledge of the properties and behavior of materials and components.
Terms like “settled” and consensus” warrant very careful epistemological analysis and understanding. The only truly settled theory is probably solely within pure mathematics.
Chad Wozniak says:
July 10, 2013 at 2:39 pm
Not to be picky about semantics, but the possibility remains, however remote it may seem, that any “settled” theory may eventually encounter a problem for which it does not work.
This will happen to every settled science. Just a question of when. But that does not matter. Our theories should be considered as ‘effective theories’, that is: theories that explain what we know at any given time. We can do no more and can demand no more.
Gunga Din says:
July 9, 2013 at 7:16 pm
A question. Is there anything to indicate (i.e. “evidence”) that the atmosphere really was as they say other than the assumption it was so their model would work?
Exactamundo.
“Janice Moore July 9 9:49:
You were right: WD40 is very important. It’s the answer to most things.[Dave F]
LOL, yes, that and duct tape!
@lsvalgaard –
Agreed, we try to use the best we have in the circumstances, and that which seems to work well – so I think we are actually in agreement as to substance on this point, and thanks for engaging me in this intellectual exercise – never hurts to have thoughts provoked.
The big kohuna I’m waiting for is how quantum mechanics will be reconciled with relativity – both borne out (so far) experimentally, yet in conflict as to some key points. That will be interesting to see, and it will be a serious test of the sort I’ve been imagining for “settled” theory..
@lsvalgaard –
P.S. I like your term “effective theories” – a very good way of qualifying the practical.
lsvalgaard says:
July 9, 2013 at 10:04 pm
Jarryd Beck says:
July 9, 2013 at 9:53 pm
based on the assumption of nuclear reactions.
From basic physics we can calculate how much energy should be released by those reactions and how many neutrinos should be produced. The calculated quantities match the observations very nicely. You see, models are an encapsulation of our knowledge. When the predictions match the theory we believe the theory.
But the neutrinos didn’t match predictions did they. So someone came up with this untestable idea of them changing “flavours” so that the theory all worked again. As with climate science, the basic idea is never questioned, but every experiment that doesn’t match just results in a tiny tweak to keep things good. In other words, it’s unfalsifiable because every experiment that would falsify it can be tweaked into the theory. Maybe it’s time for the whole thing to be thrown out and it should be started from scratch.
As Gary Hladik and Phlogiston pointed out, the explanation for the “faint young sun” paradox was explained previously without hypothesizing large amounts of greenhouse gases in the atmosphere. When the earth first formed, there would have been no continents. With an earth covered by oceans, and no clouds, the earth would have had a lower albedo than at present. With warming, more water vapor goes into the atmosphere, but you also get more clouds, increasing earth;s albedo, a strong negative feedback.
Here’s one link:
http://journals.ametsoc.org/doi/abs/10.1175/1520-0442%282001%29014%3C2976%3APBOTES%3E2.0.CO%3B2
And Clive Best addresses the obvious negative water vapor feedback here:
http://clivebest.com/blog/?p=3659
Robertv says:
July 10, 2013 at 1:48 pm
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We don’t know the orbital details of the planets in the early solar system.
Recently, I saw a programme which suggested that Jupiter was much closer to the sun. Of course, like most things, this was just speculation, since we were not around to make the required observations..
The weak sun paradox may also be relevant to free flowing water on Mars (assuming taht the evidence suggests that there was in the distant past free flowing water on Mars). How strong was the sun when water was free flowing on that planet, and what atmosphere did it then have?
In reply to:
lsvalgaard says:
July 10, 2013 at 6:32 am
William Astley says:
July 10, 2013 at 2:04 am
The high speed protons create ions in the earth’s atmosphere which effects the amount and properties of low level clouds in the atmosphere.
This peer-reviewed paper http://www.leif.org/EOS/swsc120049-GCR-Climate.pdf shos that
“there is no robust evidence of a widespread link between the cosmic ray flux and clouds”
William:
The paper you quote and thoughtful keep at your site is a hand waving attempt to counter direct observational evidence that solar magnetic cycle changes modulate planetary cloud.
It should be noted that not understanding in detail how solar magnetic cycle changes modulate planetary cloud cover does not change the reality that solar magnetic cycle changes do modulate planetary cloud cover. As I noted propaganda does not change reality.
As I note there is now observational evidence – sudden changes in climate (heavy precipitation events) and cooling at high latitudes – that support the assertion that the sudden change to the solar magnetic cycle is causing the planet to cool. The logic point is if there is suddenly the highest amount of precipitation in 200 years at multiple locations at the same latitudes that are most strong effected by cosmic ray flux changes, cosmic ray flux change is the likely cause of what is observed.
Hand waving does not remove the cyclic warming and cooling from this graph. Hand waving does not change the fact that planet cold during the Maunder minimum and the fact that the cooling cycles in this graph correlate with super Maunder like minimums.
Greenland ice temperature, last 11,000 years determined from ice core analysis, Richard Alley’s paper.
http://www.climate4you.com/images/GISP2%20TemperatureSince10700%20BP%20with%20CO2%20from%20EPICA%20DomeC.gif
Hand waving will not convince people that significant cooling of the planet is not due the change in the solar magnetic cycle, as solar cycle 24 sputters along and moves to a peculiar spotless stage. Obviously sunspots are turning into pores and the solar wind is drop at time when NASA predicted the solar cycle should be at a peak.
The following is a limited response to illustrate the hand waving.
The Svensmark’s SKY experience – which was verified by Kirby’s independent CERN experiment – shows based on experiments that cosmic ray flux increases the nucleation rate which forms clouds by a factor of 10. The paper you quote states that theoretical modeling indicates increasing nucleation rate by a factor of 10 will make no difference. Is that a joke? Is there experimental data to verify the theoretical modeling?
The logic issue of course is it possible theoretical modeling is incorrect based on the fact there are cycle of warming and cooling in the paleo record that correlate with solar magnetic cycle changes?
Marsh and Svensmark’s 2000 paper found that cosmic ray flux and low level cloud cover is high correlated for an 11 period. The paper you quote states that other parameters could have caused CR flux to be highly correlated to low level clouds. The paper you quote fails to point out the very important fact that regions that warmed in the last 70 years experience a significant reduction in cloud cover. The warmists claim any change for their theory. They stated that warming would result in a reduction in cloud cover. They fail however to explain why the reduction in cloud cover is only in the regions of the planet where cloud cover is highly sensitive to cosmic ray flux changes.
As I noted that there is a step change reduction in cloud cover starting 1995 which is due to solar wind burst modulation of planetary cloud cover and a further reduction in planetary cloud cover after that period which is due to the sudden change in the solar magnetic cycle.
The paper you quote does not mention the fact there are cycles of warming and cooling periods in the paleo climatic record that are correlated with solar magnetic changes.
The SKYexperiment provided proof of concept in that they found the formation rate of aerosol increased in the presence of ions generated using a 580 MeV electron beam (Enghoff et al. 2011). The CLOUD experiment investigated the nucleation process in more depth, demonstrating that the presence of a ternary vapour such as ammonia can enhance the nucleation rate more than ions. 100 ppt of ammonia led to a 100–1000-fold increase in the nucleation rate, while ground-level cosmic ray intensities were found to increase the nucleation rate by up to a factor of 10 (Kirkby et al. 2011).
The findings of a low level restriction to the CR-cloud correlation by Palle´ & Butler (2000) were later confirmed by Marsh & Svensmark (2000), hereafter referred to as MS00. A monthly time-series of globally averaged ISCCP low (>680 mb/<3.2 km) cloud and CR flux anomalies over the period of June 1983 to December 1994 similar to that presented in MS00 is shown in Figure 1a. MS00 also performed an analysis of local scale (individual ISCCP data pixel) correlations: a reproduction of these results is shown in Figure 1b. MS00 claimed that 15.8% of the globe showed a statistically significant positive correlation between low cloud changes and the CR flux, with a probability (p) value of achieving these results by chance of p < .001%.
http://arxiv.org/ftp/astro-ph/papers/0312/0312244.pdf
INFLUENCE OF SOLAR ACTIVITY ON STATE OF WHEAT MARKET IN MEDIEVAL ENGLAND
We show that for all 10 time moments of the solar activity minimums the observed prices were higher than prices for the correspondent time moments of maximal solar activity (100% sign correlation, on a significance level < 0.2%). We consider these results as a direct evidence of the causal connection between wheat prices bursts and solar activity.
William:
Lastly as I note there is no explanation as to 1) Why there has been no warming in the last 16 years, 2) Why there is latitudinal pattern of warming observed in the last 70 years does not agree with the CO2 forcing mechanism, and 3) Why there has been no observed warming in the tropical troposphere at roughly 8km as predicted by the AGW theory. Each of the three anomalies noted support the assertion the majority of the warming in the last 70 years was due to some other mechanism rather than the increase in atmospheric CO2.
Stephen Rasey says: July 10, 2013 at 11:06 am
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Extraordinary!
What was the point of the model run, if so little attempt was made to get the relevant starting/iniating conditions right?
Of course, given the lack of data, assumptions with respect to various parameters would have to be made, but to assume that so many were as ‘present day’ conditions is just plain stupid. Given that crazy assumption, the results of the model run are meaningless, and do not go towards explaining the faint sun paradox.
higley7 says:
July 10, 2013 at 11:14 am
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Controversial, but you are right to point out that there may be other explanations. We do not know for sure how the solar system was created. There are many contenders, each of which have problems. See for example: http://www.buzzle.com/articles/how-was-the-solar-system-formed.html
I have often wondered why, if the solar system is the result of some gravitational collapse of a gas cloud, there are so many heavy atoms in the planets (that is the rocky planets as opposed to the gas giants). If there is a gravitational collapse of a gas cloud, one would instinctively presume that the heavier atoms would be forced/attracted to the centre, ie., to the birth place of the sun such that it would contain the vast majority of the heavy atoms which made up the original gas cloud, with relatively few being left over to subsequently coalese in the formation process of the planets.
That is the beauty of science, to not know but to strive for better knowledge and understanding.
Outrageous Ampersand said, on July 10, 2013 at 11:19 am, “First post for me, … .” GOOD FOR YOU! Keep on posting! #[:)]. BTW, as you may already realize, most of the excellent posts on WUWT are never acknowledged by other commenters. Just assume you were read and rejoice in and treasure the times someone says, “Well said, old chap!” (or something like that).
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“What is the glucose eventually converted into?” [Svalgaard at 7:08AM 7/10/13]
“My question was [obviously] concerned with conditions 3 billion years ago.” [Id. at 1:02PM 7/10/13]
lol
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Dear Dr. Svalgaard,
THANK YOU FOR MAKING THE FINE DISCUSSION ABOVE POSSIBLE. Your willingness to engage in a give-and-take here is commendable. As several comments above show, nevertheless, your coldly terse, dismissive, communication style, is quite frustrating for many of us. Perhaps, you do not do this intentionally, (perhaps, you DO do it intentionally for the disingenuous sport of it) but, your sometimes non-responsive, often needlessly blunt, answers create unnecessary hostility which impedes learning. You’re better than that, Leif Svalgaard.
We want to LIKE you as a person, not just admire your intellectual ability. You make that so hard!
Remember, those fine minds (this does not, of course include the troll and the goofball from the “earth is a black body” cult) above are your FRIENDS.
With hopes (not so high, anymore, [sigh]) that you will soften your tone and honor your colleagues (and yourself) by addressing with precision the questions they ask you,
Janice
P.S. No, I do not consider myself to be one of “those fine minds,” much less, a “colleague.”
lsvalgaard says:
July 10, 2013 at 7:55 am
Gail Combs says:
July 10, 2013 at 7:49 am
limestone which is how we know they were there in the first place.
Limestone is evidence of photosynthesis??
>>>>>>>>>>>>>>>>
Limestone is evidence of life. (Some of which ate the glucose produced by photosynthesis)