Dubious "Solved It!" Boasts Mar Science Literature

In the widely-read online science magazine Quanta we recently had a story claiming that some scientists have finally solved a problem that has long baffled them: what is called the faint young sun paradox. The story is an example of what we may call a "Solved It!" story.  Such triumphal-sounding stories tend to have the characteristics listed below:

The origin of life seems to require liquid water. Geological evidence indicates that our planet was warm enough for liquid water to have existed about 3.5 billion years ago, around the time when scientists claim the first earthly life appeared. But models of solar evolution lead scientists to conclude that the sun gave off much less heat billions of years ago, only about 70% of the heat that the sun now emits. Judging only from the sun's evolution, our planet should have been completely frozen three billion years ago. This discrepancy is known as the faint young sun paradox.

The Quanta article claiming a solution to this paradox is entitled "A Solution to the Faint-Sun Paradox Reveals a Narrow Window for Life." It touts an idea of scientist James Kasting, who claims that 4.5 billion years ago the amount of carbon dioxide in the atmosphere was 10,000 times greater than today. Kasting claims that the amount of carbon dioxide has been steadily falling since the time Earth formed about 4.5 billion years ago. He claims that there was so much carbon dioxide in the atmosphere about 3.5 billion years ago that Earth would have been warm, because of the well-known greenhouse effect by which carbon dioxide in the atmosphere leads to higher temperatures. 

To try to support these claims, the Quanta article uses a staple of speculative science literature: the Guess Graph.  Graphs are usually used to present in a chart form some factual data that has been measured.  A Guess Graph is when we have some chart (such as a line graph or a bar graph or a pie chart) that uses data that was never measured, but merely speculatively imagined. Guess Graphs tend to  fool us into thinking we are seeing something factual when what we are seeing is speculative never-measured data that is not factual at all.  Guess Graphs fail to include the labeling they should have, to let us know that we are looking at mere speculations, rather than measured data.  One of the most notorious examples of a Guess Graph in scientific literature is the "composition of the universe" pie chart, which makes it sound like scientists have figured out what the universe is mainly made of. They have not done any such thing, and the "dark matter" and "dark energy" listed in such a pie chart has never actually been detected.   

The Guess Graph that appears in the Quanta article is a line graph showing the concentration of carbon in Earth's atmosphere falling steadily over 4.5 billion years, from a concentration of 10,000 times its present level to the concentration it now has. The graph is supposed to increase our confidence that James Kasting and his colleagues have solved the faint young sun paradox. But when we look at the very small print below the graph, we find that the source of the graph is listed as "Catling and Kasting."  So the article is trying to show that Kasting is on the right track by showing us some Guess Graph that Kasting himself created.  As a way of providing substantiation for a claim, this is as dubious as trying to back up Joe Smith's claims that he saw 5 flying saucers closeup by showing some bar chart made by Joe Smith, a chart indicating 2 flying saucers seen in 2019, 1 flying saucer seen in 2020, and 2 flying saucers seen in 2021. 

Why should we be very doubtful that this Guess Graph is correct? There are several reasons:

• One of the papers the Quanta article links to tells us that "the atmospheric CO2 concentration of the Archean [very early] Earth is highly uncertain."  A NASA page says, "“Atmospheric and surface conditions during the first billion years of Earth’s history are poorly understood due to the scarcity of geological and geochemical evidence."
• When you do a Google image search for "evolution of earth's atmosphere," you get a large variety of graphs from scientific publications, and quite a few of them tell a very different story than told by the Guess Graph in the Quanta Magazine article.  Some of these graphs show carbon dioxide reaching a peak about three billion years ago, and then steadily declining (rather than steadily declining over the past 4.5 billion years). 
• The main evidence given in the Quanta article to back up the Kasting claim that the early Earth may have been 70% carbon dioxide is a reference to a speculative paper that presents a speculative model. You don't substantiate one speculative model by appealing to another speculative model. 
• In a 2013 article Kasting stated that the faint young sun paradox is "one of those problems that will never really be 'solved,' because the parameters for early Earth — particularly the surface temperature — will always be negotiable."
• After stating this about the faint young sun paradox: "To resolve the paradox, Kasting (1993) suggested that high concentrations of atmospheric greenhouse gases, either CO2 or perhaps methane, prevented the oceans from freezing over," a scientific paper stated this: "In contrast, Rosing et al. (2010) have argued that the prevalence of magnetite (iron oxide) in Archean sediments and paleosols and the absence of siderite (iron carbonate) indicate that CO2 levels in the Archean atmosphere were little greater than those of today."
• A scientific paper published in 2018 gave reasons why the claims of extremely high carbon dioxide levels in the early Earth (as imagined by Kasting) are doubtful. 

The paper I refer to is the one here, which states the following:

"While several arguments have been advanced to resolve the Faint Young Sun Paradox , none is problem-free. For instance, one might try to compensate for the diminished sunlight by assuming that Earth’s early atmosphere had a far greater concentration of greenhouse gases, such as CO₂, than at present. However this hypothesis runs into difficulties. In order to maintain the Earth’s temperature above the freezing point of water during the early Archean, the abundance of CO₂ in Earth’s primeval atmosphere should have been a thousand times its present value....While CO₂ can be removed from the atmosphere by bacteria and plants during photosynthesis and also by the weathering of rock, the enormous concentrations referred to earlier seem difficult to account for. Indeed, large amounts of CO₂ in the early atmosphere would have led to the formation of the iron carbonate based compound siderite (FeCO₃). However, analysis of billion year old paleosols challenges this picture by finding no FeCO₃. Found instead are iron silicates which support a much more moderate presence of CO₂ in the early atmosphere. Moreover, it would be difficult to make CO₂ disappear almost entirely from the Earth’s atmosphere since much of it, after reacting with rocks and being used by shell-forming organisms to form CaCO₃ shells, gets deposited on the ocean floor and makes its way back into the atmosphere via volcanic activity and plate tectonics. The presence of other greenhouse gases is equally problematic."

Another doubtful example of a "Solved It!" story in the news was a story that appeard a few days on the Vice web site (www.vice.com).  The story had this two-sentence headline:

"A Billion Years of Time Are Mysteriously Missing. Scientists Think They Know Why."

This was followed by this subtitle, suggesting a "now they've finally solved it" story line:

"The Great Unconformity has baffled geologists for a century. New research points to glaciers being the culprit."

We read this explanation of the Great Unconformity:

"Sometimes, the absence of geological records is just as telling as their presence. The Great Unconformity, a missing chunk of time that appears in rocks across the world, is the ultimate example of this phenomenon. This giant lapse in Earth’s memory exceeds one billion years in some places, resulting in 550 million-year-old rocks sitting atop ancient layers that date back 1.7 billion years, with no trace of the many lost epochs in between."

You've probably never heard of this Great Unconformity. The impression we've got from geologists is that geological strata show a nice continuous record in which you can trace back time gradually, like someone backwardly flipping the pages of a big diary, without any big gaps.  Clearly this Great Unconformity is a big embarrassment to geologists, who seem to have pretty much swept it under the rug, and have mentioned it so infrequently that the average person has never heard of such a thing. 

The vice.com story mentions a very dubious idea of how all of these eons disappeared from the fossil record: "the glaciers did it." It's another dubious "solved it!" boast. The vice.com story refers to a scientific paper that refers to " the oft-held perception that continental ice sheets cannot deeply erode the upper crust," while trying to argue that continental ice sheets did deeply erode the upper crust. 

Hard-To-Explain Observational Reality	Dubious Professor Explanation of This
Sun's heat was 70% less billions of years ago, but Earth was apparently warm at that time	Billions of years ago there was 10,000 times more carbon dioxide in the atmosphere, which kept Earth warm
Every organism has in its body thousands of very complex inventions: thousands of types of functional protein molecules, each having amino acids arranged in just the right way to be functional	It was all just lucky copying errors in DNA
Galaxies don't rotate as they should, given how much regular matter we observe	For every matter particle, there are many dark matter particles, all invisible (please ignore the fact that such particles do not exist in the Standard Model of physics)
The expansion of the universe is accelerating	Most of the universe's mass-energy must be some mysterious dark energy (please ignore the fact that dark energy particles have no place in the Standard Model of physics)
The universe's earliest expansion rate seems to have incredibly fine-tuned, with the expansion rate exactly matching a "critical density" to one part in a billion trillion quadrillion	This was merely caused by a  wondrous instantaneous cosmic transmogrification, produced by a never-discovered "inflaton field" (please ignore the fact that such a field has no place in the Standard Model of physics)
Old-World monkeys closely resemble New-World monkeys, too closely to explain by convergent evolution	Monkeys rafted across the Atlantic ocean millions of years ago
All or almost all of the animal phyla appeared rather suddenly in the Cambrian Explosion	It was just higher oxygen levels that caused such a huge flood of information-rich innovation. Haven't you heard of the vast creative intelligence of oxygen molecules?
The type of cells used by mammals (eukaryotic cells) are vastly more complicated than the simplest types of cells (prokaryotic cells), with the difference being like the difference between a billionaire's mansion and a little wooden shack	Endosymbiosis: eukaryotic cells originated in a wondrous sudden leap when one cell kind of gobbled up lots of other cells, with its offspring inheriting the ingestion,  kind of like some monkey species turning into a tiger-bird-monkey species because the monkey ate a tiger and a bird.
Contrary to the predictions of quantum field theory, interstellar space is almost empty, rather than being extremely dense and heavy because of a super-abundance of virtual particles	It was just “lucky cancellations” caused by very high physics numbers that coincidentally canceled each other out in a fantastically improbable coincidence
Thousands of years ago, humans suddenly developed a host of intellectual capabilities far beyond those of any other species, such as language abilities and philosophical reasoning	Meat-eating is the reason – we needed wise, communicative  minds so we could  hunt animals. It takes a subtle literate reasoner to club an animal on the head.
For decades massive numbers of people have reported floating out of their bodies and observing them from below, while at the same time having heightened cognition	It's just vast numbers of people coincidentally having a similar hallucination, kind of like millions of people all having a hallucination of seeing a pink elephant.
When a person suffering from severe seizures has half of his brain removed to stop the seizures, there is a good preservation of memories and intelligence	Maybe your brain makes backup copies of each memory (one on the left side, and another on the right side), and maybe your brain is “super-plastic” so that the remaining half does all the work of the removed half, like some computer that keeps working well  when sawed in two
Defying odds far greater than a quadrillion-to-one, our universe has just the right fundamental constants allowing it to be habitable for life	The multiverse did it -- didn't you know we can explain our universe by referring to imaginary other universes?
A billion years are missing in geological strata	The glaciers ate up all the missing strata
We cannot find much of any evidence of the vast number of transitional fossils that should exist if there occurred the gradual evolutionary progressions assumed by the dogma of common descent	Maybe the glaciers ate up all the missing fossils

“Nuke Your Way to Life” Theory Isn't Convincing

The origin of life seems to require liquid water. Geological evidence indicates that our planet was warm enough for liquid water to have existed about 3.5 billion years ago, when the first earthly life appeared. But models of solar evolution lead scientists to conclude that the sun gave off much less heat billions of years ago. Judging only from the sun's evolution, our planet should have been completely frozen three billion years ago. This discrepancy is known as the faint young sun paradox.

Below is a diagram from a scientific paper by Shani and Shtanov discussing the faint young sun paradox. As you can see from the diagram, if we assume (for the sake of simplicity) that our planet has had its current atmosphere for the past 3 billion years, then our entire planet should have been frozen until about 1.7 billion years ago.

Some scientists have tried to solve this problem by suggesting that there were high levels of carbon dioxide in the early atmosphere, causing global warming through the greenhouse effect. But (as discussed in this paper) for such a theory to work, global carbon dioxide levels would have needed to be fifty times larger than today. Such high carbon dioxide levels would have left traces in the fossil record, traces that have not been discovered.

Recently in the news there was discussion of another theory to explain the paradox. The theory is that billions of years ago there were more solar flares: “frequent and powerful coronal mass ejection events from the young Sun—so-called superflares.” A coronal mass ejection is when the sun shoots out lot of particles. Nowadays really powerful coronal mass ejections occur only once every 30 years. But advocates of this solar flare theory claim that billions of year ago such really powerful coronal mass ejections may have occurred as often once a day. Such advocates suggest that if such flares had been enough to melt ice, they might have helped to make life possible.

Helpful solar flares? That doesn't sound very sensible when you read this description of a coronal mass ejection from another web site:

Coronal mass ejections (CMEs) are violent ejections of solar gas, plasma and electromagnetic radiation that can propel more than ten billion tons of solar matter outward from the sun’s atmosphere with the power of over a billion hydrogen bombs....They can extend billions of miles into space. Once jettisoned from the sun’s hold, they can accelerate to several million miles per hour and can reach Earth within one to three days.

A billion hydrogen bombs? So basically this attempt to resolve the early sun paradox by imagining very powerful solar flares is a kind of “nuke your way to life” theory.

There are several reasons why a straightforward version of such a theory seems to make no sense:

1. We have no known cases of polar ice that was melted because of solar flares.
2. If ice were to be melted by a short-lived solar flare zapping our planet, it would very quickly freeze again (presumably within hours), killing off any life that may have formed while liquid was available.
3. The same level of solar flare intensity needed to melt ice would have lots of life-killing radiation intensity.

A more subtle version of the solar flare theory claims that solar flares may have caused nitrous oxide (N₂0) to have formed in the atmosphere. Nitrous oxide is a greenhouse gas 300 times more powerful than carbon dioxide. Could more nitrous oxide in the atmosphere have warmed up the planet? Probably not, because in section 5.4 of this paper giving a very thorough discussion of the faint young sun paradox issue, we read the following: “Warming by nitrous oxide (N2O) has been suggested [Buick, 2007], but N2O is rapidly photodissociated in the absence of atmospheric oxygen [Roberson et al., 2011], making it an unviable option for the Archean.” Referring to the Archean eon (the the period between 4 billion years ago and 2.5 billion years ago), this statement rebuts the idea that “helpful solar flares” may have caused a greenhouse effect through a production of nitrous oxide. The objection here is that if nitrous oxide had been produced in the early atmosphere, it would have been rapidly destroyed by sunlight.

The same objection is made by scientist James Kasting. A New Scientist article says this:

Kasting thinks that ultraviolet light from the sun might have destroyed nitrous oxide before it could mix into the atmosphere. “It would take a convoluted mechanism to produce that high up in the atmosphere and then get enough of it into the lower atmosphere to produce a good greenhouse effect,” he says.

It would seem, therefore, that the faint young sun paradox is still very much with us. At the end of this scientific paper, the author makes clear that scientists have been knocking their heads on the faint young sun paradox for 40 years, but the problem refuses to go away.

The Faint Young Sun Paradox: An Unsolved Mystery

The origin of life seems to require liquid water. Geological evidence indicates that our planet was warm enough for liquid water to have existed about 3.5 billion years ago, when the first earthly life appeared. But models of solar evolution lead scientists to conclude that the sun gave off much less heat billions of years ago. Judging only from the sun's evolution, our planet should have been completely frozen three billion years ago. This discrepancy is known as the faint young sun paradox.

Below is a diagram from a scientific paper by Shani and Shtanov discussing the faint young sun paradox. As you can see from the diagram, if we assume (for the sake of simplicity) that our planet has had its current atmosphere for the past 3 billion years, then our entire planet should have been frozen until about 1.7 billion years ago.

Scientists have advanced some explanations for the faint young sun paradox, but none of them is problem-free. One explanation is that billions of years ago our planet's atmosphere was vastly different. It could have been that billions of years ago our atmosphere had vastly more carbon dioxide and methane. That would have produced a greenhouse effect many times greater than the greenhouse effect currently produced by man-made pollutants.

But there are some problems with this theory. There would have needed to be almost ridiculous amounts of carbon dioxide and methane in the atmosphere for the greenhouse effect to have been sufficient to explain the paradox. For example, in this link there's a discussion of some scientists hinting that they have solved the faint young sun paradox through a greenhouse gas explanation. But they imagine carbon dioxide levels of 20,000 parts per million – fifty times greater than today's level. Why are such high levels of greenhouse gases implausible? A good explanation is given by this scientific paper by Shani and Shtanov:

While CO₂ [carbon dioxide] can be removed from the atmosphere by bacteria and plants during photosynthesis and also by the weathering of rock, the enormous concentrations referred to earlier seem difficult to account for. Indeed, large amounts of CO₂ in the early atmosphere would have led to the formation of the iron carbonate based compound siderite (FeCO₃). However, analysis of billion year old paleosols challenges this picture by finding no FeCO₃. Found instead are iron silicates which support a much more moderate presence of CO₂ in the early atmosphere. Moreover, it would be difficult to make CO₂ disappear almost entirely from the Earth’s atmosphere since much of it, after reacting with rocks and being used by shell-forming organisms to form CaCO₃ shells, gets deposited on the ocean floor and makes its way back into the atmosphere via volcanic activity and plate tectonics . The presence of other greenhouse gases is equally problematic.

The paper makes the point that if you had once had fantastically high levels of carbon dioxide (CO₂) in the atmosphere, and that had slowly disappeared, much of that carbon dioxide would have been stored in what are called carbon dioxide “sinks.” But over the eons the carbon dioxide in those sinks would have been slowly re-released by geological processes – which would have left us with more carbon dioxide in the atmosphere than we have today.

What solution do Shani and Shtanov suggest for the faint young sun paradox? They suggest a varying gravitational constant. The gravitational constant is the fundamental constant that indicates the strength of gravitation throughout the universe. It is one of several fundamental constants that are crucially important in determining the behavior of the sun. The authors suggest that if the gravitational constant had varied by 2 percent over the past few billion years, that could explain the faint young sun paradox.

This explanation can be called something of a “Hail Mary pass.” Scientists don't quite have a rule of “if all else fails, suggest the laws of nature have changed,” but assumptions about changing laws of nature or changing physical constants are generally regarded as a kind of last resort. This paper by Pitjeva and Pitjev claims to set a limit on changes in the gravitational constant. The paper (based on spacecraft observations) concludes that the gravitational constant changes by less than 1 part in 20,000,000,000,000 per year. This conclusion is hugely inconsistent with the hypothesis of Shani and Shtanov that the faint sun paradox can be explained by assuming a 2 percent variation of the gravitational constant. If Pitjeva and Pitjev are correct, the gravitational constant could not have varied by more than 1 part in 10000 during the past five billion years, a limit which rules out a 2 parts in 100 (2 percent) variation as imagined by Shani and Shtanov.

That apparently shoots down a varying gravitational constant as an explanation for the faint young sun paradox. But what about other fundamental physical constants that the sun's behavior depends on, such as the fine-structure constant? That's not an area scientists prefer to be fiddling with, for two reasons. First, it has already been concluded that the sun is extremely sensitive to changes in the fine-structure constant, and that if it were only the tiniest bit different, the sun would be some other type of star such as a red dwarf or a blue giant. For example, this paper by a physicist finds that changing the fine-structure constant by 2 parts in 1000 would cause the earth to freeze, and changing the fine-structure constant the other way by only a few percent would cause the earth's water to boil. Given this extreme fine-tuning of the fine-structure constant, do we really want to imagine some other fine-tuning, some just-right slow change in the fine structure constant to resolve the faint young sun paradox? Also, a study based on earthly isotopes indicates that the fine-structure constant is totally invariant over the eons, varying by less than 1 part in 10,000,000,000,000,000 per year.

So where does that leave us in regard to the faint young sun paradox? We are left with an unsolved mystery. Somehow our planet was warm billions of years ago, but we really don't know why it wasn't completely frozen. Considering the matter, we should be humbled, and remember how fragmentary and incomplete our knowledge of nature is.