Earth's stable temperature past suggests other planets could also sustain life

Theories about the early days of our planet’s history vary wildly. Some studies have painted the picture of a snowball Earth, when much of its surface was frozen. Other theories have included periods that would be inhospitably hot for most current lifeforms to survive.

New research from the University of Washington suggests a milder youth for our planet. An analysis of temperature through early Earth’s history, published the week of April 2 in the Proceedings of the National Academy of Sciences, supports more moderate average temperatures throughout the billions of years when life slowly emerged on Earth.

“Ideas about the early Earth’s environment are all over the place, from a very hot world, to one locked in a permanent ice age, from a world with acidic oceans to one with seawater so alkaline it would sting your eyes,” said David Catling, a UW professor of Earth and space sciences. “These simulations show that our early world had about the same average temperature as today, and a seawater pH within roughly one unit of neutral.”

Previous research studies have put average temperatures during the Archean era, 4 to 2.5 billion years ago, as low as minus 25 degrees Celsius. Other estimates, based on different interpretations of the evidence, have placed average temperatures as high as 85 degrees Celsius, under which only heat-loving microbes that now exist in hot springs could survive.

The study significantly narrows the possible temperature of the early Earth to 0 to 50 degrees Celsius. It also finds the ocean’s pH has remained fairly moderate, gradually increasing from a slightly acidic initial value of about 6.6, through the neutral value of 7.0, to today’s slightly alkaline seawater of about 8.1. CREDIT Joshua Krissansen-Totton/University of Washington

The new results put the outer range of possible temperatures at 0 to 50 C (32 to 122 F).

“Our results show that Earth has had a moderate temperature through virtually all of its history, and that is attributable to weathering feedbacks — they do a good job at maintaining a habitable climate,” said first author Joshua Krissansen-Totton, a UW doctoral student in Earth and space sciences.

To create their estimate, the researchers took the most recent understanding for how rocks, oceans, and air temperature interact, and put that into a computer simulation of Earth’s temperature over the past 4 billion years. Their calculations included the most recent information for how seafloor weathering occurs on geologic timescales, and under different conditions.

Though we don’t think of wind and rain wearing away at the seafloor, the seabed is eroded as seawater percolates through rock on the ocean’s floor. Carbon-containing molecules settle out from the water, a process related to the temperature and acidity of the seawater, while other chemicals are dissolved from the rock.

“Seafloor weathering was more important for regulating temperature of the early Earth because there was less continental landmass at that time, the Earth’s interior was even hotter, and the seafloor crust was spreading faster, so that was providing more crust to be weathered,” Krissansen-Totton said.

The authors ran simulations for many possible scenarios for the size of the continents, the temperature sensitivity of chemical weathering and other factors to get the full range of possible scenarios for average air temperature and ocean pH through history.

“We got this initial answer that early Earth had moderate temperatures and slightly acidic ocean pH,” Krissansen-Totton said. “I tried really hard to break that, looking for assumptions that could possibly change that answer. But I found that this is a really robust result. It’s hard to imagine a realistic scenario where temperatures or pH were more extreme.”

That is good news for the search for life on other planets. If Earth’s temperature was pretty moderate throughout its history, other planets located in the habitable zone must also retain a fairly stable climate long enough for other lifeforms to evolve.

“There’s nothing particularly remarkable about these processes,” Krissansen-Totton said. “They can occur on any rocky planet with oceans. So other planets that are in the habitable zone are likely to have their climates stabilized to moderate values by these weathering feedbacks. And that’s a good thing for the search for life, because you need moderate temperatures for billions of years to have a stable environment for life to evolve.”

The results may also help shed light on what conditions were like during the early evolution of life on Earth.

“The results help us understand how natural processes kept Earth’s environment suitable for life to carry on for billions of years, from its humblest beginnings to the wonderful forms now around us,” Catling said.

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Earth has had a moderate temperature through virtually all of its history, and that is attributable to weathering feedbacks — they do a good job at maintaining a habitable climate
I had to read that three times to make certain that’s actually what they said. There’s feed backs in the system and they keep the temps habitable which by default means the tipping point scare just got smooshed.

Eustace Cranch

The tipping-point scare has always been a non-starter. Earth’s primeval atmosphere held enormous amounts of CO2 and water vapor. If Earth didn’t become anything remotely like Venus then, it never will.
Well, at least until the Sun goes into its death throes.

Chimp

It also had a lot more internal heat and volcanism. The weaker sun just doesn’t cut it.

Larry D

Back during the early period (when the Earth had an atmosphere of ~90 bar) it was kind of like Venus is today. Except it still had oceans of water. Water + CO2 + dissolved calcium and magnesium = formation of carbonate minerals, which is where that massive CO2 atmosphere went.

beng135

The only possible tipping point is toward cold, as glacial episodes demonstrate.

Huh. Err. No.
Nothing here excludes tipping points.

Eustace Cranch

Yet another content-free argumentative, Steven? Really?

TA

No CO2 tipping points.

oeman50

“Computer simulation.” Need I say more?

Jim

Humans are very creative.

MarkW

Just because climate “scientists” misuse models is not evidence that all models are useless.
Intelligent people know that they have to judge each case on it’s merits.

MarkW – “Intelligent people know that they have to judge each case on it’s merits.” – you are absolutely correct. Yes, every case must be judged on its merits. In this case, a model has been used to try to reproduce Earth’s past temperature. There are many proxy historical temperature records, which “painted the picture of a snowball Earth, when much of its surface was frozen” or”included periods that would be inhospitably hot“. Their model was unable to reproduce any such periods in Earth’s temperature history. The modellers’ conclusion should have included the possibility that their model was inadequate. Instead, they argued that their model was right and that the proxy temperature records were wrong.
Now, I’m pretty sure that some of the proxy records really are pretty inaccurate, but it does seem likely that – just one example – the Laurentide Ice Sheet really did exist and really was pretty thick, and it was so recent that more extreme such events in the past would seem to be pretty likely to have occurred. If so, then there really have been periods in Earth’s history when much of much of its surface was frozen. Similarly for hot periods.
What appears to have happened in this study is that they have used a model that is unable to reproduce past temperatures. In other word, the study has no merit. It is worth pointing out that the fact that their model is unable to reproduce past temperatures is not exactly surprising, given that climate models have been unable to reproduce past temperatures on any time scale. Having said that, however, I should point out that they put the range of Earth’s past average temperature at “0 to 50 C“, which comfortably includes both a frozen Earth and a very hot one. Also that a tiny modelling error is likely to generate very large errors over a few billion years.
[I say “very hot”, not “inhospitably hot”, because there is almost no possible average temperature at which life is impossible everywhere.].
A link to the paper would have been nice.

The possible range is even less. At a about 300K, latent heat from evaporation is enough to keep the ocean surface temperature from heating further until all of the surface water has evaporated. Unless the Sun has varied its output across a far wider range than often thought, the tropics will never freeze and the lower limit must be well above 273K. Given a relatively constant Sun, I would put the possible range of the planets average temperature since life took hold of between 5C and 25C, where the current average of about 15C is right in the middle of the theoretical/possible/practical range.

ShrNfr

“Given a relatively constant Sun” – On the scale of a million years, that is not a bad assumption I think. On the scale of a billion, I regard it as dubious.

Lance Wallace

May not be too bad an assumption. If the sun is about 10 billion years old, then it would have had about 5 billion years to settle into some sort of equilibrium before life arose.

Eustace Cranch

Best estimate nowadays has the Sun’s age at 4.5 – 5.5 billion years.

Chimp

The sun is around five billion years old, and currently gains power at about one percent per 110 million years, as it has done for billions of years.
The temperature of the Archean was not all that stable. It included at least one glaciation, around 2.9 Ma in the Pongola Supergroup of Swaziland. But more importantly, at its end occurred the first Snowball Earth episode for which there is strong evidence, ie ice at low paleolatitude.

Ah, yes, Earth’s stable temperature range — this is what baffles me in discussion about how Earth’s atmosphere affects the temperature. The focus of conversations seems always to be on how Earth’s atmosphere keeps the planet WARMER than it would otherwise be,
But the atmosphere also keeps the planet COOLER than it would otherwise be.
There is a sun side and a shadow side, you know. The sun side is COOLER because of the atmosphere. The shadow side is WARMER because of the atmosphere. This is why I think that it is incorrect to say that the atmosphere “warms” the planet. I think the correct way to say it is that the atmosphere REGULATES temperature on the planet. And this regulation has been stable over all those many years.
The right way to ask the major question of climate science, then, seems to be, “How does Earth’s atmosphere REGULATE the temperature within this habitable range?”

Thomas Homer

comment image
Something regulating atmospheric temperatures? Can we start with the obvious or stay oblivious?

Robert, an atmosphere has a net warming effect. Gravitational work done on atmospheric gases adds energy to the system.

Germinio

Zoe,
That claim is wrong. Gravity is a conservative force and therefore cannot add energy to a system.
And while the formation of the earth allowed a one time conversion of gravitational potential energy
to thermal energy that would all have radiated away millions if not billions of years ago.

Chimp

Gravitational tidal forces heat the moons of Jupiter.

Germinio

Chimp,
And the moons of jupiter are moving further away as a result. It can only happen once – although it does do so very slowly. There is no analogous process on earth. You are welcome to calculate how
much the tides heat the earth if you like but it is nowhere near sufficient to explain the earth’s climate.

Chimp

Germ,
Gravitational tidal heating in Earth’s core is less than the effect from latent heat and nuclear reactions. But it exists. The effect of surface tides is of course diminishing.

Weylan McAnally

You are absolutely correct. Gravity is constantly doing work on the Earth’s atmosphere (and every other celestial body with an atmosphere). Gravity and atmospheric mass are both stable. The energy received from the sun is also relatively stable. This is why the Earth’s temp is relatively stable. The presence or absence of “greenhouse gases” is completely without consequence. Make Earth’s atmosphere 100% nitrogen with the same overall mass and the temp would be the same.

Germ, are you stupid, or do you think I am?
Please write a scientific paper debunking what is taught in textbooks regarding gravity doing work. You should conplain to them.

MarkW

Chimp, as the moons move closer to and further away from Jupiter in their orbit, they are flexed. This causes the heating. Not gravity directly.

MarkW

Zoe, what you believe is taught in textbooks isn’t.
When a gas is pressurized, it heats up. True.
However the atmosphere was pressurized billions of years ago. It is currently under pressure, but that pressure is not increasing. Since it is not increasing, gravity isn’t doing any work on the atmosphere and isn’t heating it.

Chimp

Mark,
I know. But the source of the energy is gravitational attraction.

Mark,
You have two containers filled with water vapor. One is pressurized to 1atm, the other 10atm. You let the them settle down to common temperature. Next, you shine a powerful EM source on them (emulating sun). Which gets hotter?
It should be obviously that the more pressured one will get hotter, and all your talk is garbage.

“but that pressure is not increasing. Since it is not increasing, gravity isn’t doing any work on the atmosphere and isn’t heating it.”
P=mg/A
W=mgh
What you said is nonsense. Work done is not dependant on pressure change. Please stop embarassing yourself.

gravity doesn’t add energy. It converts between PE and KE which. changes temperature without. any change in total energy.

MarkW

Zoe, neither gets warmer.
If the pressure isn’t changing, there is no work being done.
If the pressure doesn’t change, the temperature doesn’t change.
The only one embarrassing themselves is you.

Coach Springer

So, finally settled!

Ben of Houston

It’s still models all the way down. The results make a lot of sense, but as nice as it sounds, it’s still conjecture based on what “should” have happened.

Hivemind

Agreed, we need some ground truthing. At some stage, some real scientist needs to get into their time machine and go back with a thermometer & measure the actual temperature.

John harmsworth

CO2 up-Co2 down. Solar inputs up-solar inputs down. Comet and meteor impacts drive massive climatic events and earth recovers. It’s worse than we thought?
More like the climate of Earth is hopelessly benign and unchangeable!

Trebla

The Earth’s climate HAS to be stable or we wouldn’t be here to argue over climate change. Evolution takes so much time. Were the Greek philosophers who lived thousands of years ago less intelligent than we are?

Carbon Bigfoot

What evolution? You all need to read “Darwin’s Doubt” by Dr. Steven Meyer where he dispenses that fool’s errand with aplomb.

Chimp

Meyer’s book is pure, unadulterated garbage, a pack of lies from start to finish. He should be ashamed to have perpetrated such blatant mendacity.
Decades of new fossil finds show that the Cambrian Explosion was no different from other explosions of diversity following mass extinctions. The ever-expanding Ediacaran (latest Precambrian) fauna show the antecedents of Cambrian organisms. The Burgess Shale itself contains impressions of the little soft arthropods ancestral to larger, hard-shelled trilobites.
Evolution is a scientific fact, ie an observation, repeatedly observed in nature, created and recreated in the lab. The term also applies to the body of theory seeking to explain those observations. Same as with gravity, although evolution is much better understood than universal gravitation.

Chimp
John Harmsworth

You should try reading “On the Origin of Secies” by one Charles Darwin. There is a reason why he over powered the creationist paradigm of his day. His arguments were simple, powerful and very complete. Reading it is a revelation of what genius and good science can achieve.

Chimp

On the end-Precambrian animals which preceded the larger, harder Cambrian forms:
Ediacaran developmental biology
https://onlinelibrary.wiley.com/doi/full/10.1111/brv.12379
It doesn’t discuss sponges much, but fossils of small proto-Poriferans have been found from the same period.
Tried to post this before, but it hasn’t yet showed up. Please excuse if it appears twice.
[Found and rescued. Deleted the duplicate. -mod]

Chimp

Mod,
Thanks very much for that effort and for all that you do!

MarkW

It’s stable in as much as it varies within limits.

Chimp

Evolution of higher classifications, ie families, orders, classes and phyla, appears usually to take time, but the evolution of new species and genera can and often does occur in a single generation.
Abiogenesis, the development of the first living things via chemical evolution, permitting biological evolution to begin, seems to have occurred rather rapidly on Earth, leading some to posit that complete, simple organisms, not just their organic chemical compound constituent components, arrived here on asteroids.

MarkW

LIfe appears to have started almost as soon as the planet was cool enough for liquid water to form.
However complex life didn’t show up until about 300 million years ago. Some 4 billion years after life first appeared.

Chimp

Mark,
What do you mean by complex life?
Microbes formed colonies billions of years ago. The first true multicellular organisms evolved about a billion years ago, not just 300 Ma.
We have fossil protosponges from about 700 Ma and complex, macroscopic animals from well over 600 Ma. Large animals with hard body parts showed up before 540 Ma.

Chimp

Three hundred Ma, at the end of the Carboniferous Period, there were already sphenacodonts, advanced synapsids ancestral to mammals:comment image
Most famous of this group is probably Early Permian Dimetrodon.

Jim Masterson

>>
Chimp
April 3, 2018 at 6:19 pm
Microbes formed colonies billions of years ago. The first true multicellular organisms evolved about a billion years ago, not just 300 Ma.
<<
Although there are large colonies of Prokaryotic cells, multi-cellular organisms appear to be composed exclusively of Eukaryotic cells. The so-called “Cambrian explosion” is easy to explain–the appearance of Eukaryota made it possible–the evolution that created Eukaryota took several billion years.
Jim

Tom Halla

A computer simulation not producing a dread scenario? There must be some sort of error! /sard

The Reverend Badger

The postulation that “weathering feedbacks” are the mechanism leading to relative temperature stability is interesting but I don’t see much hard proof. A more plausible explanation might be something more solid physically such as temperature being determined by distance from the star, atmospheric composition and gravity (ref Nikolov and Zeller of course). We should have an open mind and consider all these possibilities.
Closing off one possible area of enquiry is not helpful.

Windchaser

and gravity (ref Nikolov and Zeller of course).

Gravity sets the lapse rate, but it can’t set the surface temperature. Gravity doesn’t work as a long-term source of energy, so any energy generated by gravitational compression will just be radiated away. It physically can’t have much of an effect on surface temperatures unless you throw out the law of conservation of energy.

commieBob

The lapse rate helps regulate the temperature. If the surface temperature is below a certain level, there won’t be convection. If the surface temperature is high enough, convection will remove heat from the surface.
The thickness of the atmosphere and the lapse rate provides a pretty good approximation of the surface temperature on Mars, the Earth, and Venus. link

Thomas Homer

” Gravity doesn’t work as a long-term source of energy ”
Oceanic and atmospheric tides on Earth, are they ‘long term’?

Wind, Gravity works once? Weird.

MarkW

That’s not even close to what he said.
What he said that the compression of the atmosphere (from 0 to 1 atm) only happens once.

And what drives the air molecules up and down in convection cycle?
You do realize that rotational work is still work, right?

MarkW

As air moves up, it cools.
As air moves down, it heats.
No net energy gain.

Your car engine doesn’t do any work either, then. Half your tire goes up, half your tire goes down.
Solar radiation causes a decrease in molecule density, Gravity then drives denser molecules down which forces less denser molecules up. Two forces at work: EM and Gravity. You only want to count EM. You think denser and less dense molecules switching places is not semi-rotational work, but it is. And there’s friction involved too.

Bryan A

Must also add Atmospheric Pressure as a means of initial temperature control

MarkW

Zoe, if your car was off the ground, than your pathetic little analogy would be relevant.
Since the wheels turning causes the car to move forward, there is a net change of position and work is being done.
The sun warms all molecules, (effectively, I don’t want to get into absorbtion and other processes).
True if some molecules warm faster than others, they will rise. As they rise they lose pressure and cool.
Since some molecules are rising, other molecules have to be falling. Those molecules get pressurized and warm.
Other than the sunlight coming in, no work is being done.

Mark
lol, you’re an idiot.
if the tire is off the ground you think your engine does no work spinning it?
How absurd. The work done is F*2*pi*r.
If the force of gravity causes one molecule to go down and another up, this is not zero work. Gravity needs to work hard to pull one down, so that the other can be displaced up.
Jump out of a building please. According to you, all the air you displaced (was below you, now above you) on your way down proves no work was done.
‘net work’ is meaningless. You can travel around the world to the same spot, and claim that net work (force times distance) was zero. That’s cute, but you still expended energy.

Jim Masterson

>>
MarkW
April 3, 2018 at 6:15 pm
As air moves up, it cools.
As air moves down, it heats.
No net energy gain.
<<
It’s basically how thunderstorms work. No net energy there, right? /sarc
Jim

Hivemind

Weathering feedbacks was discussed in an article published by Scientific American in the early 1970’s (in those days they still did real science). It concluded that the Earth’s temperature was quite stable, even in the complete absence of life.

Weylan McAnally

Nikolov and Zeller are 100% correct. I have not read any paper that disputes their formulas that predict with high accuracy the surface temps on many planets and large moons. The only criticism I have seen is that their paper was pulled. Of course it was pulled because they used fake names when submitting the paper.

Mark
lol, you’re an idiot.
if the tire is off the ground you think your engine does no work spinning it?
How absurd. The work done is F*2*pi*r.
If the force of gravity causes one molecule to go down and another up, this is not zero work. Gravity needs to work hard to pull one down, so that the other can be displaced up.
Jump out of a building please. According to you, all the air you displaced (was below you, now above you) on your way down proves no work was done.
‘net work’ is meaningless. You can travel around the world to the same spot, and claim that net work (force times distance) was zero. That’s cute, but you still expended energy.

TonyL

Our results show that Earth has had a moderate temperature through virtually all of its history, and that is attributable to weathering feedbacks — they do a good job at maintaining a habitable climate

So what they are really saying is that conditions are favorable for life forms which came into existence within those exact same conditions.

Seafloor weathering was more important for regulating temperature of the early Earth because there was less continental landmass at that time

The early Earth had an atmosphere of methane, ammonia and carbon dioxide when life first appeared. Cyanobacteria changed the atmosphere to nitrogen and oxygen, radically transforming the environment of the entire planet.
But none of that had anything to do with anything.
It was the weathering of the seafloor that controlled all.

because you need moderate temperatures for billions of years to have a stable environment for life to evolve

They are quite sure of this. They must have conducted many “Origin Of Life” or biogenisys experiments on their laboratory planets.

Ben of Houston

Yeah, I have my concerns about what they were including or excluding as well. However, fairly stable climate regulated by weather feedback does not seem an unreasonable hypothesis to start with. Someone a lot smarter than me would have to check how it checks out with other evidence such as the fossil record.

Lance Wallace

“Seafloor weathering was more important for regulating temperature of the early Earth ”
Still true? Then move over, CO2–new guy on the block!

JimG1

From “Move it on Over” by Hank Williams. “Move over skinny dog the fat dog’s movin in.”

Earthling2

Our Moon here on Earth had a lot to do with creating a long term stable seasonal climate, by creating stability in Earth’s rotation and axis so as we don’t have wildly oscillating seasons. The moon’s gravitational pull is probably key to making Earth a livable planet by moderating the degree of wobble in Earth’s axial tilt, which led to a relatively stable climate over billions of years where life could flourish. It may be the vast majority of interstellar planets in the goldilocks zone have no significant moon that provides for enough of a stable wobble to allow life to evolve much more than basic life, such as single cell organisms. So maybe other planets have life, but never a stable enough climate to allow for long term evolution of higher life forms to ever take hold. Pure speculation regarding life on other solar systems, but we do know without the Moon here at planet Earth, we would not have stable long term climate due to moderation of planetary mechanics. Plus it is thought that the tides, mainly caused by the Moon, allowed life to flourish on land, due to an intertidal zone that promoted amphibious life to develop, which later led to land based life. We just may be a fairly significant remarkable planet in the scheme of things.

MarkW

If the latest theories regarding how the moon were created are correct, than having a moon like ours is going to be a fairly rare occurrence.

since moons are community and theories are almost always wrong I tend to doubt any theory that argues the earth is somehow special. most of the great errors in science start with the author at the center of the universe.

MarkW

In 100 years of trying, the current theory is the only one that has been able to explain how the moon might have been formed. It also explains other intriguing facts known about the moon.

Jim

Sustaining life is completely different from expecting life to evolve there from SCRATCH.

Chimp

Life developed from scratch on Earth, where “scratch” means monomers and polymers of organic chemical compounds, so presumably can and will do so under similar conditions on other planets and moons.

No, life was seeded by aliens. They will probably come back at some point and ask us to be allies in their wars.

Chimp

If they need our help, they’re in trouble.

MarkW

We have people with super powers. Hollywood would never lie to me. Right?

Chimp

Well, polar bears surely have superpowers of strength, fat tolerance and sense of smell. Maybe the aliens will ask for their help.
And the elephants, given their ultrasound hearing. Not to mention whales.

Hivemind

“be allies in their wars”
Uh, no… “Harvest us for protein.”

Chimp

Rapid emergence of RNA polymers in “warm little ponds” on emerging volcanic land, without intervention of alien beings, just space rocks:
Origin of the RNA world: The fate of nucleobases in warm little ponds
http://www.pnas.org/content/114/43/11327
Before the origin of simple cellular life, the building blocks of RNA (nucleotides) had to form and polymerize in favorable environments on early Earth. At this time, meteorites and interplanetary dust particles delivered organics such as nucleobases (the characteristic molecules of nucleotides) to warm little ponds whose wet–dry cycles promoted rapid polymerization. We build a comprehensive numerical model for the evolution of nucleobases in warm little ponds leading to the emergence of the first nucleotides and RNA. We couple Earth’s early evolution with complex prebiotic chemistry in these environments. We find that RNA polymers must have emerged very quickly after the deposition of meteorites (less than a few years). Their constituent nucleobases were primarily meteoritic in origin and not from interplanetary dust particles. Ponds appeared as continents rose out of the early global ocean, but this increasing availability of “targets” for meteorites was offset by declining meteorite bombardment rates. Moreover, the rapid losses of nucleobases to pond seepage during wet periods, and to UV photodissociation during dry periods, mean that the synthesis of nucleotides and their polymerization into RNA occurred in just one to a few wet–dry cycles. Under these conditions, RNA polymers likely appeared before 4.17 billion years ago.

We are offspring of aliens. We are aliens. We came to this planet and the environment changed us. The aliens don’t eat their own.
To think we’re the only ones and the first ones is ridiculous.
The standard evolution story is just a circular reasoning story, and nothing more.
When you exclude outside forces as an assumption then “obviously” we evolved from pond scum.

Chimp

Zoe,
Nobody excludes anything. It’s just that science requires evidence. You’re free to hypothesize aliens, but without evidence that’s no better than myth. Not that some scientists might not agree with you, at least to the extent of advocating panspermia.
However no such extravagant, extrascientific explanation is required. We didn’t develop from pond scum, but from organic chemical monomers such as phospholipids, nucleotides and amino acids, which spontaneously self-assemble in aqueous solution, even in space. The processes by which these monomers then form polymers without the bioenzymes available today is an exciting area of current research.
Pond scum came much later, after the first protocells had evolved into prokaryotes, to include bacteria, which then evolved into photosynthesizing cyanobacteria and eventually into eukaryotic algae, the ancestors of plants.

So lack of evidence of aliens must support your theory of spontaneous self-creation?
Of course there is evidence. Plenty of it, and only a tiny percent exposed as hoaxes or some other phenomena.
“We didn’t develop from pond scum, but from organic chemical monomers such as phospholipids, nucleotides and amino acids, which spontaneously self-assemble in aqueous solution”
I call that pond scum. Might not be technically correct.
Surely these “life elements” require some exotic electric fields to coalesce from simpler atoms and molecules?
Might aliens have helped this process along?
Just because you didn’t see something happen doesn’t mean it supports your theory, which you also didn’t see happen.
You rely on inference just as I do. Am I wrong?

Chimp

Zoe,
For instance, the Murchison Meteorite contained a vast array of complex organic compounds, shown to be inherent to the body and not resulting from terrestrial contamination:
https://en.wikipedia.org/wiki/Murchison_meteorite
The chemical constituents of life have also, as I noted, been produced in the lab through simple means, such as heating. In 1961, Oro showed that the important nucleobase adenine (A in the genetic code and precursor of cellular energy molecules ATP and AMP) can be made simply by heating HCN.
https://www.sciencedirect.com/science/article/pii/0003986161900339

And Murchison can’t be a remnant of an alien or alien-seeded planet?
Oh it contains A, therefore … we evolved from that. Imagination of the gaps, inference.

Chimp

Zoe,
Murchison is a chunk of a particular kind of asteroid. No mystery there at all.
We evolved from a variety of organic chemical compounds, not just adenine.

MarkW

If we came from aliens, where did the aliens come from?
Did these aliens also plant millions of fossils scattered through out the rock strata just to disguise their work?

MarkW

Zoe, nobody claims certainty. If you have a better theory and can offer evidence to support it, please present it.

And asteroids and meteors can not be fragments of a previous planet?
Just because you know what we’re made out of doesn’t mean we self-assembled.

MarkW,
And where did original self-organizing matter come from? Nothing? The aliens came from other aliens … back to the original creator: god. You just take it for granted that some matter arranges itself, but never question if there is a purpose to that,or that that aspect of nature was itself designed.
By the philosphy of naturalism you are compelled to make the claims you do, but I hope you’re honest enough to admit that it’s just a philosophy and it may not ultimately be true.

Chimp

Zoe,
We’ve observed the protoplanetary disks around other, sun-like stars, so it’s reasonable to assume that asteroids, planets and moons formed by accretion around the sun, just as we see happening elsewhere in the universe.
When stars go red giant or supernova, planets near them are atomized. There are rogue planets orbiting the galactic center in interstellar space, but conditions on them aren’t conducive to life.
We know that amino acids, nucleobases and other organic compound monomers essential to life self-assemble. We know that those monomers polymerize with and without bioenzymes. So, yes, we do know that nucleic acids, proteins and other organics needed for life can arise spontaneously, without any help from alien intelligences.
Dunno how old you are, but odds are that life will be made artificially in the lab during your lifetime, using an entirely natural pathway which would have existed on the early earth or within asteroids.

Chimp

Zoe Phin April 3, 2018 at 6:36 pm
The elements which combine to form the organic compounds which constitute life are created inside stars. No need for a “God”, whatever that might be. Imagining such an entity explains nothing.
We happen to live in a universe the rules of which allow H atoms to exist, which allows stars to fuse H into He, thence into heavier elements, including those of which we are made. Life arises under certain conditions thanks to chemistry. No supernatural intervention required.

“We happen to live in a universe the rules of which allow H atoms to exist”
“Happen”
“rules of which”
Lol. Yup, no need to question why or how that is.
I see you’ve started repeating yourself, I must have gotten to you. Are you incapable of understanding whatI said or you refusing to do so?
I understand your commitment to metaphysical naturalism.

Chimp

Zoe,
I understand what you claim. You’re free to believe whatever you want. It’s just not science, which requires evidence.
If I’m repeating myself, it’s because you don’t seem to understand what I’m saying.
There is no need for a God to explain the physical rules which obtain in our universe. Other universes could have other rules, in which hydrogen atoms can’t form. Indeed, they probably do, but so far physical evidence is slim for the existence of other universes, although math suggests that they must exist, including the one which preceded our universe.
I’ll repeat myself to the extent that there is no reason to imagine something like a God. Energy and matter are simply products of spacetime. No further explanation needed or possible. But if supposing that such an entity exists works for you, great! It’s just not science, which requires naturalistic explanations, ie based upon observations of nature, not conjectured supernatural beings.

You just evoked multiple universes without evidence. That’s your god. Multiverse is supernatural – beyond observed nature. Congratulations!

Chimp

Zoe,
Multiverses aren’t supernatural. At worst they’re metaphysical, but as they arise from M Theory equations, which are testable, they arguably qualify as hypothetical natural phenomena.
Physical observational evidence for their existence has been adduced, prominently by a female astrophysicist, but most of her colleagues aren’t yet convinced. But in modern cosmological theory, they should exist, if our best models are in fact descriptive of reality.
The scientific method is a far cry from just making stuff up about gods and aliens.

Your spontaneous evolution theory defies entropy theory.
In one, things become more diverse and specific, in the other everything becomes a cold homogeneous dead blob of uniformity.
Which pet naturalistic theory is your god?

Chimp

Zoe Phin April 3, 2018 at 8:19 pm
No, the fact of evolution doesn’t violate any laws of physics.
Life is not a closed system.

Chimp

Zoe,
Maybe you haven’t studied string of M theory. Multiverses arise out of M theory just as gravitational waves arise from Einstein’s general theory of relativity. He predicted such waves based upon the equations of GRT. But it was a long time before they were actually observed.

Ok, you don’t understand the allegory of god. You’re mired in preconceptions of a word.
You don’t know what the universe is contained in, but you’re sure it’s not god, because that would give too much credit to your ancients, so instead you adopted the World Egg myth (Big Bang) which is even older than monotheism. What a strange man you are. Are you aware of the fact that you’re bounded by philosphical bias and not science? Of course you’re not.
“Life is not a closed system”
Oh it’s fed from an external source? God or aliens or multiverses, or black holes, or warm holes? They’re all on the same of fantasm or reality, aren’t they? Can you understand that?
Thanks for admitting the universe and the life in it is not a closed system.

Multiverses don’t arrive from M-Theory, it arrives from ancient philosophy. The math dresses up philosophy. Math doesn’t create ideas, it organizes them.
There’s a reason science is a branch of metaphysics.

Chimp

Zoe,
No, the multiverse arises from modern theoretical physics. It owes nothing whatsoever to any ancient philosophy. What ancient cosmology do you imagine inspired the multiverse?

“No, the multiverse arises from modern theoretical physics. It owes nothing whatsoever to any ancient philosophy. What ancient cosmology do you imagine inspired the multiverse?”
LOL, so confident in your ignorance, then you want my help? No, you seek it out yourself if you’re interested. You seem like an asshole who will project his bias into the past and say:
“Well these ancients were not talking exactly about M-Theory, so they couldn’t have meant the current theory of multiverses.”

Chimp

Zoe,
I didn’t ask for your help. I asked you to explain what your unsupported assertion about ancient philosophy meant. You provided no reference to what ancient philosophy you had in mind.
IMO any disinterested observer here would find me too patient in trying to explain science to you, and that the asshole is, well, not I.

Chimp

Zoe,
Of what do you imagine me to be ignorant and confident? It seems to me that all the confidence from ignorance is on your part.

Your confidence and ignorance is shown by how quickly you though that your ancients were not clever enough to imagine alternative parallel universes (sometimes from a common source). Really? You think it’s a new idea? Nah, it’s as old as dirt (don’t take that literally, though you never know with YOUR TYPE).

Chimp

Zoe,
IOW, you can’t cite any ancient philosopher of the multiverse.
But even if you could, you still can’t show that such a not in evidence philosopher had any effect whatsoever on the multiverse arising from modern cosmological thought based upon M theory.
Surely you must see how utterly baseless and pathetic your drivel is.

“IOW, you can’t cite any ancient philosopher of the multiverse.”
http://cosmos.nautil.us/short/128/the-multiverse-is-an-ancient-idea
“But even if you could, you still can’t show that such a not in evidence philosopher had any effect whatsoever on the multiverse arising from modern cosmological thought based upon M theory.”
Who created M-Theory and why couldn’t he be inspired by ancient ideas? You think he just got it from nowhere?
Get real. No creative person exists in a vacuum.

“Harvest us for protein.”
≠======
to serve man.

MarkW

No, asteroids cannot be part of previous planets.
Self organizing molecules come from the same place all other molecules come from. Atoms that were created by stars.

Chimp

Yes, Zoe, you are wrong.
I don’t infer that amino acids and nucleobases self-assemble. I’ve seen them do it in nature and made them do so in the lab. They have been observed in meteorites and created through spontaneous reactions on earth. No strange electrical forces required, just those seen every day in every way on earth and in space.
Complex organic compounds abound in the universe. No aliens need apply. Compounds of the most common elements form naturally pretty much everywhere. After H and He, C, O and N are the most plentiful atoms in the solar system and visible universe. Carbohydrates (and hydrocarbons) can’t help but form.

Chimp,
I meant the next level up from those “life elements”, obviously. Have you observed that?

Chimp

Zoe,
Yes. I and a host of others have observed spontaneous polymerization of monomers into short chains, ie oligomers. The trick is getting them to keep lengthening into longer polymers before breaking apart. A variety of prebiotic enzymes to catalyze this reaction are under investigation and have shown not only promise, but effectiveness.
Polymerizing without bioenzymes short peptide chains of amino acids into proteins and short chains of nucleotides into RNA and DNA is simply a chemical engineering problem, presenting no insurmountable difficulties. That the amino acids and nucleotides form spontaneously is simply an observation of nature. The problem of isolating, concentrating and connecting the monomers so that they can form long chains is well on its way to solution.

Chimp

PS:
Just to be clear, a nucleotide is a five carbon sugar (ribose or deoxyribose) attached to a phosphate group and one of five nucleobases. The backbone of nucleic acids, ie RNA and DNA, is made by the sugar’s sharing phosphate groups with neighboring sugars. The other end of each sugar is attached to an A, G, C, T or U nucleobase (T in DNA and U in RNA).
Deoxyribose lacks one O atom, so can form a double helix rather than a simple strand, which makes DNA a more stable repository of genetic information.
RNA has the wonderful property of being able to form into complex shapes, giving it enzymatic activity, ie it makes ribozymes. That is serves both as a library of genetic information and as an enzyme capable of catalyzing reactions was an important discovery in the RNA World hypothesis.
The peptide bonds between amino acids form readily, but again, keeping the chain growing into long polymers is the trick in making proteins with enzymatic activity. However, recently researchers have found enzymatic function in short oligomers of amino acids, ie peptides.

“A variety of prebiotic enzymes to catalyze this reaction are under investigation and have shown not only promise, but effectiveness.”
“The problem of isolating, concentrating and connecting the monomers so that they can form long chains is well on its way to solution.”
So you have full faith that humans will figure this out and prove intelligence can create life, but not alien intelligence?
You’re sure that aliens didn’t figure that out a long time ago and we might be its end product?
So where do you see humanity going?
Will we ever seed life on other planets?

Chimp

Zoe,
The evolutionary successors of humans might well colonize our galaxy. But probably not.

MarkW

Zoe, if aliens are responsible for us, then who is responsible for the aliens?
There must be a first species somewhere. By what evidence do you assume that it can’t be us?

“There must be a first species somewhere. By what evidence do you assume that it can’t be us?”
Because of where we are in the galaxy. I assume the outside is oldest? Either way we are half way from the center and rim. Because life is everywhere, we did not come first.

Chimp

Zoe,
Life might well be everywhere, but we don’t yet know that. We do know that the constituents of life are everywhere, ie organic compounds.
The galactic center has the oldest stars, but the black hole there and intense radiation suggest it’s not a very hospitable locale for life.

Strange that the oldest stars would be found in the center. Galaxies start off as little blobs and then expand out as they rotate, so one would think the oldest would be on the edges of the galaxy .. getting cooler. Typically heat dissipates out.

Chimp

Zoe,
The universe often seems strange and surprising. The oldest stars in the Milky Way are nearly as old as the Universe itself and thus probably formed shortly after the Dark Ages of the Big Bang. Globular clusters are among the oldest objects in the Milky Way, which thus set a lower limit on its age.
Galaxies tend to coalesce, as gravity draws them together. Galaxies thus grow over time, and the Milky Way is still growing. The Milky Way and the Andromeda Galaxy are a binary system of giant spiral galaxies belonging to a group of 50 closely bound galaxies known as the Local Group, surrounded by a Local Void, itself being part of the Virgo Supercluster.
Two smaller galaxies and a number of dwarf galaxies in the Local Group orbit the Milky Way. The largest of these is the Large Magellanic Cloud, which has a close companion, the Small Magellanic Cloud. Andromeda is the largest galaxy in the Local Group, with about twice as many stars as the Milky Way and measuring more than twice as far across.
Merger among some or all of these large and dwarf galaxies is likely in future.

So you believe in the Big Bang (a rehash of the World Egg myth) and you believe gravity tends to coalesce things. Expansion and Contraction at the same time.
Do you have other mutally conntradictory beliefs that you want to add into that mix?

Chimp

Zoe,
I don’t “believe” in the Big Bang Theory. I’m convinced by the evidence to share the conclusions of those who have formulated the theory based upon the observational evidence. Like all scientific theories, it is always subject to revision as more evidence becomes available.
I don’t know to what you refer by expansion and contraction. The universe is visibly expanding, and that expansion appears to be accelerating. Yet within the expanding universe, galaxies naturally draw closer to each other under gravitational attraction, ie by warping spacetime.
Why is this observation hard for you to accept?

“those who have formulated the theory based upon the observational evidence”
The observational evidence was redshift, which has at least 10 alternative explanations. Then once redshift was “accepted” as assuming expansion another giant leap was made, that it was eternal expansion (why couldn’t we just have 1,234,567 years of expansion – that’s a possibility), an eternal expansion from the World Egg.
Your formulators had a philosophical bias. Due to a quirk/luck of history it became mainstream.
How does proof of expansion NOW prove expansion for billions of years? Did you observe that?
Don’t bring up CMB, that too has dozens of alternative explanations.
Basically everything you believe has alterative explanations, but your priests hide that from you. You will deny this.
Tell me why you adopt what is popular in the here and now, and neglect other possibilities that unfortunately did not RANDOMLY become as popular?

Because the Big Bang defies gravity in the first place. Proponents of BBT claim the singularity was infinitely hot and infinitely dense (normally only a product of infinite gravity), but then it just reversed its gravity and began to expand, “however” later on some places then coalesced by gravity that just so happened to have come back in that spot.
Come on, give a girl a break, you know it’s just self-contradictory rhetoric.

Chimp

Zoe,
You really ought to study physics, astrophysics and cosmology before presuming to comment thereupon.
The red shift is not the basis of the Big Bang. What showed that hypothesis broadly correct, as opposed to the competing Steady State hypothesis, was the Cosmic Microwave Background Radiation, accidentally discovered in 1964.
If you imagine that the Big Bang defies gravity, you have never studied it or any other aspect of theoretical and experimental physics. Gravity is indeed the only fundamental force yet to be unified under the BBT, but the hypothesis in no way defies gravity.
Had you ever actually studied what you deem yourself qualified to comment upon, you’d know that expansion of the universe is not a gravitational phenomenon. It occurs at faster than light speed, because it is the expansion of spacetime, not relative motion within or warping of spacetime.
If there be a God, I’m pretty sure that It would not approve of a young lady who presumes to know things which plainly she has never bothered to study or think about.

No such thing as spacetime. Time is not a dimension, it’s a ratio of fast movement in space to slower movement in space. For example, ~9 billion vibrations of cesieum-133 in SPACE is a second, and we can compare that to other events.
Time is an aspect of motion in space. If all objects in space hypothetically froze, you couldn’t tell Time in its own dimension, because it doesn’t have one.
spacetime becomes a useless exercise in folding space by space.
“It occurs at faster than light speed,”
Thanks for debunking Einstein.
“because it is the expansion of spacetime.”
Funny that the Standard Model doesn’t list “expansion of spacetime” as a fundemental force. That’s because it doesn’t exist.
You sure believe in some strange fantasies. But it’s OK, they are approved by your priests.
“Gravity is indeed the only fundamental force yet to be unified under the BBT, but the hypothesis in no way defies gravity.”
LMAO

Chimp

Zoe,
Had you ever studied physics, you’d know that spacetime is reality.
Einstein predicted that gravitational waves, ie ripples in spacetime, would be observed as a result of collisions of massive stars. Sure enough, as soon as we had the instruments in place to observe gravitational waves, we found ripples in spacetime from the collision of neutron stars.

If only your skepticism extended beyond climate science you might find out that “consensus” science is ruining cosmology as well. But you haven’t spent the time, instead you lecture me on things I already learned but rejected for good reasons.
At least we agree gravity Works on the atmosphere.

Chimp

Zoe,
I’m positive that I’ve spent far more time than you studying not only cosmology, but every other scientific discipline.
Same goes for ancient philosophy.

Maybe you have, but not critically. I could have written exactly what you wrote to me 10 years ago. Now I find it wrong and boring. You’re a follower, not a thinker like my husband. I’m disappointed you taught me nothing new.

But thank you for trying. I appreciate the effort.

Chimp

Zoe,
If I’ve taught you nothing, it’s only because you don’t want to learn.

Chimp

Zoe,
You’re welcome.

“If I’ve taught you nothing, it’s only because you don’t want to learn.”
No, it’s because you’re unoriginal and I’m aware of better arguments. You couldn’t respond to my arguments. You failed my test.

Zoe Chimp Mark et el, I read through your discussions quite interesting. Then i see the old chestnut wether it was a big bang or a steady state universe. If it was a big bang, like all explosions the middle would be empty and a shell of projectiles would be moving outward? If it was steady state there would be no beginning and no end. The densest part of our universe is the middle and new stuff is coming from there.
This would suggest a third theory is needed, to my mind the middle of the universe is a matter generator and from that swirls out new matter that under some of the physical laws that we know form suns. These create heavier matter eventually dying and exploding, that gives us an entirely new chain of events that leads to smaller and quieter suns and planets coalescing into galaxies.
My theorising has more logic than the other two theories when one looks toward the centre of the universe.

MarkW

Zoe, like all of your assumptions, the assumption that the outside must be oldest is faulty.
I like the way you evade the question as to where the first life came from.
Then again, evasion and bad science are all you have generated to date.

MarkW

Wayne, that’s true for an explosion within a universe, but when the explosiion is the universe itself you end up with what we see now. Everything flying away from everything. Space itself expanding.

“Space itself expanding.”
This notion is so stupid. Where did the energt come to expand space? What activated and modulated its use to create varying rates of expansion?
Secondly, imagine:
AoooB, where o is space
Then is became:
AooooooB
So what you’re saying is that space created space!
That’s never been observed, only infered from observation. Maybe the chain of assumptions was wrong?

“obviously” we evolved from pond scum.
========
lawyers and politicians are the living proof.

JimG1

What effect on climate would the fact that earth’s day was 12 to 16 hours 3 to 4 billion years ago and still changing? Changing temperature of the sun, effects? With and without moon’s tidal effects? Orbital, axial tilt and precession over geologic periods? Just saying. Lots of variables other than just weathering.

Javier

“These simulations show…
“Our results show that Earth has had a moderate temperature through virtually all of its history, and that is attributable to weathering feedbacks.

There are no scientific results based on any type of evidence. Just computer simulations. They haven’t shown anything except that they can program a computer to give them that particular answer.
Unless they can validate the model for the task it is just a computer game, not science.

Kurt

Exactly right. The computers are being used, not as a tool to gain meaningful insight into what conditions were really like billions of years ago, but instead merely as a tool to produce more research. In other words, the procedure for this “study” was adopted not due to any reasoned expectation of accuracy, but merely because the procedure was needed to produce “results” – any “results.”

Bruce Cobb

We know that there must be other planets capable of sustaining life, because Warmists are always coyly talking about “the planet”, but never which one. Furthermore, none of the conditions they catastrophise on about, the response of climate to CO2, etc. matches what we have here on planet earth. Therefore, they must be from some other planet (which one remains a mystery). QED.

Jerry Henson

Le Chatelier’s principle works or we wouldn’t be here. Humans haven’t changed that.

oakgeo

That’s what I learned in school many years back, that the Earth could be viewed as a macro-homeostatic system.

whiten

If I am allowed to throw my silly card claim, as with all this weirdness it will not be so wild at the least…
“At ~ 2.5-2.8 billion years ago the Earth, this glacial world then, starts significantly moving and “transforming” to a water world, out of a glacial world condition.”
Problem with this that could be is (are) ,,, the RF forcing, radiation as per concept of, have or had no much to do with it, no much meaning of the Goldilocks zone in this aspect of a probable earlier glacial Earth…
Please do not harshly jump the gun, just throwing in my candidacy claim in all this mess of claims about, if not much mind it… 🙂
cheers

mellyrn

If they are trying to say that there were no ice ages and no hothouse periods, that it was always just like it is today, I see no point in trying to read the paper at all.
As far as I can see, their models say, “given what we currently think we know about weathering processes, this [model result] is what should have been going on in the past.” That’s respectable; then go out and look at, I dunno, actual rocks, and see if the rocks agree. If yes, yer onto something. If no, then either your understanding of weathering is missing something; there are other factors (the solar system passing through some galactic-scale cloud?); or both.
You don’t get to run your computer simulation and just declare that “is” how it was.

Germinio

Mellyrn,
They are not denying the existence of ice ages or hot house periods. They are claiming that the range of temperatures in the past was between 0C and 50C rather than previous estimates of -25C to 95C. The average temperature during an ice age lies within their range of possible temperatures.
It is also worth noting that temperatures of close to 0C and 50C would probably spell the end for multi-cellular life on Earth.

Chimp

During the depths of Snowball Earth episodes, our planet’s temperature has been estimated at -50 degrees C.
http://www.astrobio.net/news-exclusive/improving-understanding-of-snowball-earth/
Maybe not right, but these computer simulations can’t be considered dispositive.
At the other end, following the collision thought to have spawned the Moon, Earth was estimated to have been around 2300 Kelvin (3,680°F). Our atmosphere was of gaseous rock.
But leaving off the Hadean Eon, the hottest we’ve been since then was probably during the latest Neoproterozoic Era. At that time, thick, calcium-rich rock layers sat directly on top of deposits left behind by retreating glaciers. This indicates that temperatures rose significantly near the end of the Neoproterozoic, perhaps reaching a global average higher than 32.2°C (90° Fahrenheit, v. today’s global average lower than 60°F.)
There could have been a brief excursion as high as 27°C (80.6°F) during the end Permian mass extinction event.
The toastiest times of the mid-Cretaceous and PETM might have been around 73°F, but equable from equator to poles.
Heat-loving microbes’ optimum growth temperature of 50 to 60 degrees C can be found in hot springs and organic composts. Organisms unable to withstand such surface heat can retreat into the crust of the planet.

mellyrn

Thank you; however, “Theories about the early days of our planet’s history vary wildly. Some studies have painted the picture of a snowball Earth” together with “Other theories have included periods that would be inhospitably hot” (emphasis added) implies that “snowball Earth” theories somehow exclude hot periods at some time along the way. WTF?
Theories “vary wildly”, from snowball-Earthdom in “some” studies while “other” theories include hothouses. Whaaat? I don’t know of any theory at all that says “the” early Earth “was” a snowball with no hot periods; it seems pretty solid that there was a snowball period, maybe 200 million years’ worth — but most geologic theory I’ve ever read considers Earth to have been generally snug and warm, with some variation.
I know of no theory that believes in “inhospitably” hot periods — at least, not once the crust settled down. The Mesozoic got pretty warm, but hardly “inhospitable”!
Nothing in the article suggests that they mean, “while sometimes there were ice ages and sometimes hothouses, mostly it was [as per our modeling].” They write of geologic theory as if they last looked at the topic in grade school, and don’t remember that any too clearly.
We don’t know what causes ice sheets to advance and retreat. We have some speculations (Milankovitch cycles), but we don’t know. We don’t know what causes Earth to go into an ice age (an age when ice sheets are possible) at all, nor yet come out of one. Given that ignorance, there must be any number of factors they can’t include in their models.
So they don’t get modern geologic theories right, and yet they presume to overturn them.
They run models — intensively and rigorously, apparently — but don’t check their models against actual geologic data.
No point reading anything else they write.

John Harmsworth

Perhaps that renowned interpreter of the hidden secrets of tree rings, Michael Mann can reinvent himself as a rock whisperer and get us the low-down on the past. I he doesn’t know his way around low down then I don’t know who does.
Maybe the rocks would do his math for him. That would be an improvement!

“Our results show that Earth has had a moderate temperature through virtually all of its history, and that is attributable to weathering feedbacks — they do a good job at maintaining a habitable climate,” said first author Joshua Krissansen-Totton, a UW doctoral student in Earth and space sciences.

I’d say it is attributable, not to “weathering feedbacks”, but to active thermoregulation by emergent phenomena.
w.

T. Fry

What a load of garbage.
It takes scientists PHD’s (Piled High and Deep) to make claims like this. So what if the temperature is in the right range? Do they know how many other factors are necessary for a planet to sustain life, never mind the problem of how it got there in the first place?

Smart Rock

Call me skeptical, but if GCM models have trouble modelling today’s climate, what is the likelihood that these folks can model climate 3 or 4 billion years ago with any approach to accuracy? The data to start with are so fuzzy, that it’s probably no more than building an edifice on a foundation of educated guesses.
Good try, and of course we all like the bit about climate being stable. Makes a change to see that in print instead of tipping points and disaster.

joelobryan

The IPCC scientists also needs about 2.5 billion more years to narrow down their ECS estimate. Send more money.

Something crucially important is left out here, and that is the stabilizing gravitational influence of Earth’s relatively large natural satellite, Moon. It’s presence, acting on Earth’s equatorial bulge, and on its tidal bulges, has prevented Earth’s rotational axis from deviating more than a degree or two from its present value of 23.4 degrees from a vertical to the plane of the ecliptic. This factor, combined with the early development of photosynthetic life that could introduce oxygen to the atmosphere, thus permitting a protective ozone shield and a stratosphere, is responsible, more than anything else, for the extreme stability of terrestrial environments. Other planets, whose spin axes were free to swing through large angles of nutation, presented different areas of the planets to solar radiation during their revolution around Sun. Most particularly, their north and south polar hemispheres would have been exposed to 24/7 solar radiation during solstices, resulting in the evaporation and photodissociation of the planets’ oceans. Deuterium to hydrogen ratios of nearly 5 and over 100 relative to Earth’s indicate that such a scenario actually came about in the cases of Mars and Venus,respectively, causing significant and total loss of the planets’ oceans.