UEA: Oceans moderate the climate
Story submitted by Eric Worrall
h/t The Register – University of East Anglia researchers have challenged the view that any planet in the Goldilocks zone (the right distance from a star so water is likely to be liquid) is likely to be habitable.
New research shows that without an ocean, and the right rate of rotation, a planet is likely to experience extremes of temperature which make it unlikely to harbour life.
From the Abstract; http://online.liebertpub.com/doi/abs/10.1089/ast.2014.1171
“The climate and, hence, potential habitability of a planet crucially depends on how its atmospheric and ocean circulation transports heat from warmer to cooler regions. However, previous studies of planetary climate have concentrated on modeling the dynamics of atmospheres, while dramatically simplifying the treatment of oceans, which neglects or misrepresents the effect of the ocean in the total heat transport. Even the majority of studies with a dynamic ocean have used a simple so-called aquaplanet that has no continental barriers, which is a configuration that dramatically changes the ocean dynamics.
Here, the significance of the response of poleward ocean heat transport to planetary rotation period is shown with a simple meridional barrier—the simplest representation of any continental configuration. The poleward ocean heat transport increases significantly as the planetary rotation period is increased. The peak heat transport more than doubles when the rotation period is increased by a factor of ten. There are also significant changes to ocean temperature at depth, with implications for the carbon cycle. There is strong agreement between the model results and a scale analysis of the governing equations. This result highlights the importance of both planetary rotation period and the ocean circulation when considering planetary habitability.”
According to Dr. David Stevens, from UEA school of mathematics;
“Mars for example is in the sun’s habitable zone, but it has no oceans – causing air temperatures to swing over a range of 100°C. Oceans help to make a planet’s climate more stable, so factoring them into climate models is vital for knowing whether the planet could develop and sustain life,”
Life is not just an alignment of proteins and DNA etc. If it were so, it would be easy to reanimate a freshly killed organism. Repair the damage to a dead bacteria and reanimate. Even with all the proteins and cell mechanisms in place, we are clueless, as to how one can make it stand up and dance. GK
> > Mike18xx: (see large moon post up-page)
> richard verney: “I accept that there is a strong argument that a moon may be required, but you have to bear in mind that our relationship with our moon has varied dramatically these past 4.5 billion years, it use to be significantly closer, and this resulted in a day lasting about 4 hours (not 24 hours). the day has got longer as the moon has receded….”
— The only difference orbital distance makes is the size of the tides; what’s important is that the impact by “Theia” blew off the lighter silicate mantle and (hypothesized) super-deep ocean, and, post-impact, imparted a strong magnetic field due to tidal action upon the Earth’s molten iron outer core.
https://en.wikipedia.org/wiki/Giant_impact_hypothesis#Possible_origin_of_Theia
> “The majority of planets in our solar systems have moons, so moons are not at all rare…”
— Only Pluto has a moon which is a significant fraction of planetary mass. E.g., Mars’ two moons are comparatively infinitesimal.
> “But even if the statistics for a planet with a moon is vanishingly small, just by force of numbers that would suggest that there are still plenty of ‘Earth’ like planets theoretically possible.”
— It drastically thins the numbers. I.e., it’s entirely possible that *half* of galactic neighborhood sun-type solar systems have rocky planets in habitual zones, but that *none* of them have an Earth-life planet due to lack of a large moons creating suitable conditions for land-based life.
Without a large, similarly-formed moon, the associated planet will lack rapid rotation, strong magnetic fields, crustal plate-tectonics, and a neither too thick nor thin ocean.
The total amount of oxygen in the atmosphere – 21% is equal to all the organic carbon produced by photosynthesis that is currently buried in rocks. This level essentially doesn’t change despite how much we burn fossil fuels. A lump of coal represents an oxygen source for the atmosphere. Since the industrial revolution oxygen levels in the atmosphere have changed insignificantly, because this fossil fuels are a tiny portion of total buried carbon. Life and the earth’s geo-climate feedbacks keep CO2 levels very low and that is why we measure % rises in CO2. Naturally CO2 levels are kept very low because so that the climate remains optimized for large liquid oceans, photosynthesis and multi-cellular life. A value of 300 ppm CO2 optimises from radiative heat loss from the atmosphere to space at current temperatures. When eventually mankind either develops a nuclear energy source (e.g. fusion) or else returns to neolithic living, CO2 levels will return to optimum levels of around 300 ppm at least until the next ice age starts.
What is optimum about 300ppm?
Optimum for who? Typical does not equal best.
Gary Hladik says:
So it’s turtles aliens all the way down? :-)”
Yup. And don’t get me wrong – I love science. I of course thoroughly reject a young earth – that’s ridiculous given a mountain of evidence for a billions-years-old earth. I just as strongly reject the idea that we evolved, starting with inorganic matter, by mere natural process/chance in a mere 4-5 billion odd years. For one thing, the probability – both for life’s beginning (even laying aside what, exactly, caused the “spark of life” in inorganic matter once it somehow assembled itself into the simplest life-supporting form possible) and also evolved to us in the estimated age of the earth is basically zero. Not in the age of the earth, not in the age of the universe, not in multiple order of magnitudes higher than the age of the universe.
The truth, I think, lies somewhere between a young earth and some billions of years of total natural/random processes. I’m willing to accept just about anything in between – God can do whatever the Mordor he wants. But, science will never use the “G” word – so when the probabilities are just too great to ignore, and as time has gone by science discovers life to be more and more complex, not less – there will have to be some kind of explanation. My guess is that the alien thing will suffice.
Frodo,
You have written 2 posts which attempt to argue the near impossibility of our universe and life arising by chance.
You first stated that the ratio of the gravitational constant to the EM constant is so finely tuned that it cannot differ from 1 part in 10^40. This sounds like a slam dunk if you consider only the traditional universe theory – that is our universe, all that is, came into being from a single event. However, I am gladdened by the more recent conjectures around various kinds of multiple events. There are some physicists who are talking about infinite multiverses which seed infinities more when their branes touch and form further big bangs.
If ours is one of an infinite number, it isn’t any surprise that our universe is so finely tuned. In fact, there must logically be an infinity of such perfectly tuned universes.
On your second point of how impossible it is for even bacteria to have evolved in the time available, a similar argument can be applied. In fact, there isn’t any need to postulate multi verses at all. Our universe contains so many stars that with all these trillions upon trillions of life laboratories working in parallel, there has been plenty of time for the numbers game to play out on one of them. And whatever world this happened to be, we would be discussing the same thing. Why our world?
However, I will go further and take issue with your assertion that we would even need the amount of time that you suggest. Since we don’t know how life started we cannot possibly say how long it should take. That is a bit like an argumentum ad ignoratium.
I started a response, it was a little too snarky. Also, I have a number of other things to do. Instead, I‘m perfectly willing for anyone interested to read your stuff and my stuff, then, hopefully, research the matter for themselves, and come to their own conclusions. Have a great day!
Liquid water + organic compounds + energy source + a billion years or so
IMO the above could readily produce sing-celled life and has done so in many, many places in the universe. Maybe even elsewhere in our own solar system, e.g. Europa.
Don’t see where tides/rotation/magnetic fields are necessary.
Single-celled life, sorry.
Remember, out of all the octillions of organic molecules dancing around in the universe, a self-replicating molecule only has to happen once and then it’s off to the races.
This is a new study?
Maybe I’ve got my info wrong but I thought this was already well-known. Certainly to SF writers, it was…
Vince Causey says:
July 23, 2014 at 5:51 am
Frodo,
However, I will go further and take issue with your assertion that we would even need the amount of time that you suggest. Since we don’t know how life started we cannot possibly say how long it should take. That is a bit like an argumentum ad ignoratium.
——————
This of course goes both ways, whether argueing for life being likely or unlikely. Man kind does not posses the knowledge to make a more informed opinion than ‘I don’t know’ (at least not publicly, que twilight zone). The error bars on any calculation on the likelyhood of life off earth are as large as your imagination, or, if you prefer Descartes, as large as your will.
Frodo says (July 23, 2014 at 5:42 am): “My guess is that the alien thing will suffice.”
My point is that the G–er, “aliens”–all the way down thing doesn’t suffice. At some point you have to put up a “NO MORE TURTLES/ALIENS BEYOND THIS POINT” sign, or you’ve explained nothing.
As for probabilities, I have conclusively proved Hubert Yockey’s calculations wrong, just as I have proved that Hulk can wield Thor’s hammer (by wielding Thor with the hammer in Thor’s grasp). 🙂
This is kind of obvious. Oceans bring thermal inertia to the climate. In addition many bioscientists concerned with the origin of life think that oceans may be needed as the incubator.
just as I have proved that Hulk can wield Thor’s hammer (by wielding Thor with the hammer in Thor’s grasp)
###
No you haven’t. You still need to prove that the Hulk can wield Thor whilst Thor wields his hammer.
Eustace
“Don’t see where tides/rotation/magnetic fields are necessary.”
Without planetary magnetic field, no shield against cosmic rays and solar UV light. Cosmic rays can damage DNA and UV light is a germicide. They kill microbes. Without single-cell life, no multi-cell life. Or maybe evolution can bypass the microbe stage and the organic molecules will turn into a cat. But the cat will acquire cancer and die.
Sorry it’s the atmosphere that shields UV light. So you also need an atmosphere.
On second thought, if the creatures live under the sea, they are protected from cosmic rays and UV light even without atmosphere and magnetic field. It will be a world of fishes and the man from Atlantis.
How much UV gets down to a “black smoker” on the ocean bottom?
Liquid water? Check. Plenty of energy? Check. Organic molecules? Check.
And in Earth’s case, lots of life.
“How much UV gets down to a “black smoker” on the ocean bottom?”
I’d say virtually none. Spent nuclear fuel rods emit gamma rays which are 10,000 times more energetic than UV. The fuel rods are kept in cooling pools 26 ft. underwater. Nuclear plant workers walk above these pools protected only by 26 ft. of water. It is safe and they don’t usually die of gamma ray radiation poisoning. We can throw away our nuclear waste in the sea. 5,000 ft. of water is a lot safer than 26 ft. But the fishes will protest.
Frodo~ The evolutionary biologists attempting to unravel the origins of life do not typically begin their narratives with genes, and would never imagine that the simplest biological structures we find today, viruses, sprang into existence spontaneously with hundreds of genes that magically work well together. DNA cannot replicate itself on its own, so obviously could not have been present at the origin of life. In short~ there was an evolutionary process before genes. By bringing up viruses, you inadvertently created an analogy which helps tune the mind as to HOW to think about the origins of life. Viruses cannot exist alone. They are not alive, but have DNA which can be understood as a string of genes. Viruses arose upon a scaffold that previously existed~ living things with DNA. Viruses cannot exist or function without the capability of living cells to translate DNA code into proteins and enzymes. Likewise, DNA cannot exist on its own. RNA is required so that DNA can replicate itself and thus create an evolutionary process. DNA cannot replicate on its own, but RNA can, so logically, RNA is a candidate for a precursor to DNA, just as living DNA bearing cells were precursors to viruses. There are RNA viruses too, but my point is, that you cannot use the simplest gene structures that are currently known to exist, and then assume they must represent the simplest living things that have ever existed. That displays both a lack of understanding of the current evolutionary origins point of view, and a lack of imagination. The DNA evolution of life we study at present was most certainly erected upon a scaffold of much simpler RNA evolution, but there are scant traces of the scaffold left (but they are there, and still essential to the current process). The RNA WORLD which is proposed to have existed before the DNA WORLD, is so logical and parsimonious that it is silly to criticize it, because of how evolution works. The driving process in evolution is replication. Any molecule that makes copies of itself will start an evolutionary process. DNA doesn’t make copies of itself, so genes cannot be present at the origin of life. RNA does self-replicate, and can spontaneously form out of an animo acid bath and electrical energy (and yes, animo acids are well known to spontaneously form in the same conditions). I am not going to take the time to cite references regarding the details of what I’m saying, because A) the gist of this post is that you are thinking about it the wrong way, and B) I don’t really care if you agree or not, and no appeal to ‘authority’ would sway your point of view, because you don’t understand the fundamentals of evolution. All creationist arguments against the theory of evolution are founded upon complete ignorance of what the theory of evolution is about. A good test is this~ if your understanding of evolutionary theory is that it is about random chance, then you don’t understand it, and obviously haven’t even tried to. That is the simplest way I can put it.
For an informative discussion on the molecular origin of life, including “Spiegelmann’s monster”, a simple self-replicating virus in a beaker of simple chemicals, check out the last couple of chapters of The Ancestor’s Tale by Richard Dawkins.
Ric Werme says:
July 22, 2014 at 4:58 am
…
I don’t know what the seasonal range of surface temps on Venus is. … I doubt it’s 100C°.
More like 1K. CO2 is such an effective receiver and re-transmitter of IR that day/night pole/equator variation/differences are tiny. They’re short-circuited at lightspeed.
Sorry, mods. Close italics tag after 100°C.