Cassandra has moved. Ugo Bardi publishes now on a new site called "The Seneca Effect."

Saturday, September 14, 2013

The next ten billion years revisited

Thou must now at last perceive of what universe thou art a part, and of what administrator of the universe thy existence is an efflux, and that a limit of time is fixed for thee, which if thou dost not use for clearing away the clouds from thy mind, it will go and thou wilt go, and it will never return. (Marcus Aurelius, "Meditations")

You can't understand a man's actions if you don't take into account that what he does on a specific day is the result of events that took place during his whole lifetime and that will result in more events in the future. It is the same for a whole planet, although the lifespan of the Earth is much longer than that of a single human being. If we want to understand what's happening today on our planet, we must try to understand how it has changed over the eons to become what it his now and what it may become in the future.

That of looking at the whole span of the history of a whole planet or even of the whole universe has a special flavor; even though none of us will ever witness the ultimate end of our biosphere, still the idea that we can imagine it is a source of great fascination. And it is not something new: it is a whole field of human thought that we can call "eschatology", from the Greek world "eskhatos", meaning "the last".

In the history of people musing on the ultimate end of everything, we can see two lines of thought that we might dub, purely for convenience, the "Western" and the "Eastern" views. The Western view sees the universe, humans and everything, as having a finite and limited lifespan, the Eastern view sees the same concepts as an infinite series of cycles. The single cycle view is typical of thinkers steeped in the Greek-Latin tradition and of the monotheistic religions that arose around the Mediterranean area. In its basic form, the idea is that God created the world and that the world will have an end (apocalypse, from a Greek world meaning "revelation"). Human beings are supposed to live a one-time trial. You succeed or you don't, but God doesn't give you another chance. East-Asian thought seems to have been based on a different viewpoint: Buddhism sees the soul as forever reincarnating in new bodies. There is no end and no beginning to this endless cyucle that the wise may, however, be able to interrupt.

It is hard to say what factors created these two different schools of thought. One thing we know, however, is that today Western science can be seen as continuing the ancient tradition, that of the single cycle. For what we know, the universe appeared in a specific event called the "Big Bang" and it is destined to end, according to the most recent data, as a cold and dreary place made out of matter scattered over an immensely large volume. Back in  1956, Isaac Asimov was reasoning within this tradition when he wrote a story titled "The Last Question", where he imagined humankind engaged in a forever quest for how to reverse the cycle and rejuvenate the universe. But Asimov was also thinking outside the Western box when he proposed at the end that the question could be answered, although not by humans themselves but by the computer they had created. As there is nobody to tell the answer to, the computer proceeds to carry on the answer in practice by creating light and restarting the universe.

I must have read this old story by Isaac Asimov when I was, maybe, 15 years old and it inspired a post that I wrote on "Cassandra's Legacy" with the title "The Next Ten Billion Years" for which I borrowed from Asimov the same finale. This post of mine had a certain success and, recently, John Michael Greer ("The Archdruid") commented on it and produced his own version of the next ten billion years as he sees them. It is by all means a fascinating piece but different from mine in a deep philosophical sense. True to his role of druid, Greer explicitly rejects the Christian "one-cycle" tradition and leans on the multiple cycle view of the universe, for instance saying that, ten million years from now,

No fewer than 8,639 global civilizations have risen and fallen over the last ten million years, each with its own unique sciences, technologies, arts, literatures, philosophies, and ways of thinking about the cosmos.

and then he goes on to describe several non-human civilizations arising and disappearing in the span of several hundred million years, including one derived from raccoons, one from ravens, and one from freshwater clams. There is no evidence in Greer's vision of the entropy caused winding down of the universe. The atoms that once formed the Earth and its inhabitants are flung away in space by the last convulsion of the Sun and end up forming another star and a number of planets. The cycle restarts.

As I said, we are discussing philosophical matters and we'll never find an agreement on what the Earth will look like - say - ten million years from now. So, I'll just comment here on how science gives us very strong evidence for a "one-cycle" Earth. With that, I don't mean just an apocalyptic end of our planet when it will be finally consumed by an expanding Sun. No, the Earth has changed all the time over its four billion years of existence, it keeps changing, and the changes are profound and irreversible.

What we call the "biosphere" has been part of this great, long lasting cycle. As all things that are born and are destined to die, the biosphere must peak and decline. Actually, it has peaked and it is declining. The biosphere productivity over the past 3.5 billion years looks a little like a gigantic Hubbert peak according to a paper by Franck, Bounama and Von Bloh,

In a previous post, I wrote about this graph that:

As you see, the Earth's biosphere, Gaia, peaked with the start of the Phanerozoic age, about 500 million years ago. Afterwards, it declined. Of course, there is plenty of uncertainty in this kind of studies, but they are based on known facts about planetary homeostasis. We know that the sun's irradiation keeps increasing with time at a rate of around 1% every 100 million years. That should have resulted in the planet warming up, gradually, but the homeostatic mechanisms of the ecosphere have maintained approximately constant temperatures by gradually lowering the concentration of CO2 in the atmosphere. However, there is a limit: the CO2 concentration cannot go below the minimum level that makes photosynthesis possible; otherwise Gaia "dies".

So, at some moment in the future, planetary homeostasis will cease to be able to stabilize temperatures. When we reach that point, temperatures will start rising and, eventually, the earth will be sterilized. According to Franck et al., in about 600 million years from now the earth will have become too hot for multicellular creatures to exist.

Of course, the extinction of the biosphere is not for tomorrow or, at least, the calculations say so. But it is like estimating one's lifespan from statistical data. Theoretically, the homeostatic mechanisms that operate your body could keep you alive until reach a respectable age; sure, but homoeostasis is never perfect. For instance, there are mechanisms in your body designed to reverse the effects of traumas. You may expect these mechanisms to work well if you are young but, if you are hit by a truck at full speed, well, you end up on the wrong side of the life expectancy statistics.

Similar considerations apply to Gaia. Theoretically, the planetary homeostatic mechanisms should keep Gaia alive for hundreds of millions of years, but what about major perturbations, some planetary equivalent of being hit by a truck? Would Gaia be able to recover from a human caused runaway greenhouse catastrophe?

We cannot say for sure. What we can say is that we are living in a period called the "sixth extinction," similar to other major past extinctions. In most cases, these extinctions appear to have been caused by an increase in the concentration of greenhouse gases in the atmosphere. The sixth extinction, too, is taking place in correspondence to a rise of the concentration of carbon dioxide in the atmosphere that may never have happened so fast in the history of the planet. This rapid rise is also taking place under a solar irradiation that has never been so high as it is today. We can't rule out that the sixth extinction will be the last one.

So, as I said at the beginning, the present and the future of a single person can be understood from his or her past, and it is the same for the Earth (aka, "Gaia"). Science is telling us very, very strongly that the present moment is unique in the history of the planet: the future will not be like the past. It is true that, if we fail to survive as a civilization, there will be probably space for more human civilizations. And, if we go extinct, there may be space for the evolution of new sentient species. But all that will happen in different conditions and along a downward slope.

New human civilizations developing within the next few hundred thousand years will not have the coal and the fossil hydrocarbons that we have consumed today. In a few hundred million years from now, new sentient species might find oil that has reformed in shallow anoxic seas - but they won't have coal, the result of very special conditions occurring only once (for what we know) on this planet. And they will live in a planet with a much reduced biological productivity in comparison to ours. That doesn't mean that they won't be able to develop spaceflight, as Greer proposes - the future is full of opportunities, but it is never like the past.

In the end, these considerations give us just a hint of the sheer immensity of the future and of how difficult is the human attempt to conceive it. For what we know, we are a small ripple on the top of a gigantic tsunami wave that's crashing on some remote shore. As a ripple disappears, new ones appear, but the wave keeps rolling onward to its inevitable end. And yet, we know so little: there may be other shores, other waves, the universal sea may never stop to roll, and light and darkness may exchange places in a never ending dance. So, just as Asimov concluded his story, someday, the words "Let there be light" may be said again. And there will be light again.  

ever moving.
So it can act as the mother
of all things.
Not knowing its real name
we only call it the Way

If it must be named, 
let its name be Great.
Greatness means going on,
going on means going far,
and going far means turning back

(Tao Te King, as reported by Ursula K. Le Guin)


  1. "So, just as Asimov concluded his story, someone, someday, may say again "Let there be light". And there will be light again"

    YES, and a great post that I think -among other things- also helps to put "sustainability" in perspective.

    And with a little help also from "Gravity's Engines" (see links below) the multiverse should "keep right on trucking" for a long time (in new "updated spacetime" ?) to come...

  2. I think when talking about Cycles vs One-Shots, people tend to try to make the facts fit what they believe, rather than make what they believe fit the facts.

    In the case of the Earth and multiple cycles, a philosophy developed that because there have been multiple cycles before this, there will be multiple cycles afterwards also. A Historian like JMG looks at historical cycles of Civilizations, and then projects there will be many more similar cycles.

    This doesn't take into account the increasing complexity of the cycles, the increased use of Energy through the cycles and the changing Energy output of the Sun as time goes by here.

    The geological conditions which got us to where we are today are unlikely to repeat. Beyond that, in the 500M years or so of multicellular life on the planet, only one Sentient species ever evolved. So it is a pretty big stretch to imagine that 2 more will evolve after this in maybe 200M more years where such life is even possible at all on the planet.

    This doesn't mean there are not Universal Cycles of recreation, there may well be but not here on Earth in the time left, at least it is highly unlikely.

    About the only thing you can say for sure is that regardless of whether we burned all that oil, we would eventually go extinct anyhow. We may have accelerated the process some here, as I said over on George's blog, its like Smoking for a person. Quitting might help you live a little longer, but you still would end up dead in the end. The only CHANCE was to get off the Earth in some sort of Interstellar Starship, and we shot the wad trying to come up with Energy Technology that would make such a thing possible. That Holy Grail was Fusion Power. We never got it, and as things spin down here, it is unlikely we ever will now.

    So now it is not a matter of IF we will go extinct, just WHEN.


    1. Certain concepts (and realities) such as homeastasis and endless cycles (or cycles that go on for a while but then eventually end) may or may not apply in the same way at different scales.

      T. Colin Cambell in his book "Whole: Rethinking the Science of Nutrition" discusses homeostasis in the human body system and its sub-systems (interactive also with the human "mind" or experiential or brain system) quite well and very interestingly in the context of explaining why "reductionist medical science" (as opposed to holistic science) has missed the point regarding many aspects of human body functioning and so called "cures" such as for instance many of those for cancer, heart disease, diabetes and some other diseases which do not really work and hence the "diseases" cannot really be "cured" by medicines except for specific types and cases, whereas diet and nutrition reduce their incidence very substantially and often also permanently and reversibly. (contrary to what medicine and doctors, steeped in the ideology of reductionist science typically would have us believe) (since they believe it themselves within the "mainstream paradigm" of western and now also a lot of eastern medicine)

      Instead regarding "cycles" at the human level I personally do NOT believe they exist because there is no scientific evidence for people being reborn at least not if one takes "people" to mean a biological entity as opposed to a spiritual one which in my own opinion does not exist. But although I am fundamentally a product of Western civilization (Italian and American) I have lived here in Buddhist Thailand over the past 12 years during which I also have worked all over Asia. So I know the "Eastern" way of thinking on some of these matters first hand. In my view different religions (and the philosophies and cosmologies that underpin them) have different ways of regulating human thinking and the so called "ethical" behavior of human beings. (since all societies need to find ways to regulate it or they will not survive) (please note what may happen with nuclear warfare if "thou shalt not kill" is not followed) In the West we tend to be regulated by "commandments" whereas in the East people are more regulated by the kind of "karma" they build up or don't build up during a particular cycle (but also based on following or not following certain principles with the number and specificity varying depending on whether one is a Buddhist monk or an average person) which they happen to be in, and this will affect their next cycle, but also what will happen in this cycle further downstream.

      In the Western tradition and its belief systems (in particular the Roman Catholic one) based on how humans performed during their lifetime with respect to the ten commandments they then go either to hell or heaven or purgatory (so there is SOME flexibility to graduate upwards after due "cleansing and purification and atonement) and dead people are also placed in the ground whereas in the East they typically are cremated and their smoke goes back into the cosmic whole from which they then re-emerge later in assorted possible re-incarnations and the cycle repeats itself forever. (the preceding of course very roughly speaking and probably much more in line with "reductionist" analysis instead of "holistic") (CONTINUES BELOW)

    2. On the basis of science however (at least as I believe it is typically understood) there is no afterlife and there is no human rebirth or re-incarnation and therefore both the Western and the Eastern religious traditions are wrong. (this even though there of course are also some religious scientists and some theologians who think scientifically; and some would argue that theology and science (and also art) are inseparable but I personally do not find such ways of thinking all that helpful or useful (at least not from a utilitarian perspective)

      So science I think has something fairly clear to say with respect to both homeostasis AND cycles at the level of the human body or of the human being.

      At the level of the biosphere and GAIA (which encompasses it) matters are less clear cut because we are not able to observe the birth and the death of the biosphere in the same way as the birth and the death of a single human (though we have many clues as to the birth) simply because the time scales are enormously longer. But my own view is that the biosphere also has a birth, a life and an end in the Greek eschatological sense. We cannot know for sure one way or the other whether once the current GAIA (biosphere plus physical planet in ongoing interaction) dies whether it will be reborn or not because a) "we" (neither ourselves as individual humans nor the human race as a whole) will be around at that time to witness any rebirth or lack thereof. And so b) we have to rely on our "projective" capacities to try to guess; capacities which are notoriously weak and also probably because of certain inherent properties of systems which make it impossible to know how they will behave too far into the future. But we do know with a reasonable probability that the sun will blow up in however many billions more years thereby putting an end to planet earth.

      The human body system is extremely complex (perhaps as complex as at least the basics of the universe) but it is observable over its roughly 100 year life span. The biosphere is more complex than the human system because it contains it and also a huge number of other living entities and systems about as complex. (a frog and a frog brain is less complex than a human or a human brain but is still "rather complex") (and both a frog and a human seems to be equally stupid in terms of jumping out of the pot in time). Yet if GAIA's behavior is viewed as an overall "emergent property" at a higher level it may not necessarily be that much more complex than a human body. (wholes and and higher order systems and their behaviors can be viewed and understood without necessarily referring back to the internal behavior and dynamics of each of their single parts or sub-systems) In fact understanding anything relies heavily on shutting out much of what is going on at other levels without which complexity would overwhelm us.

      Physical planet earth is in one sense (and over shorter time frames) a separate thing from GAIA although the two are extremely inter-related (carbon cycle, oxygen and etc.) and but as an entity probably will end when the sun as a star is likely to "blow up in its face". So it probably will NOT go through cycles. (CONTINUES BELOW)

    3. What about the universe? Here we risk once again having to be guided by the realm of philosophy more than on the realm of science (to the extent it can guide beyond contemplation) and probably again because of the impossibly long time scale to make reliable “scientific” observations. Though through WMAP and etc. we can go back to at least the beginning of the latest big bang 13.7 billion years ago which gives us clues as to whether it may have been only the last in a series that also will continue, or the one and only big bang. (the big crunch seems to be ruled out at least for now given the observable ongoing expansion of the universe) (but perhaps will be "ruled in" again later).

      There may be yet another intriguing possibility which I think is "fun" to at least consider: Just as light theoretically and observably has a "dual nature" (the Copenhagen and also other later interpretations) in the sense that it is both a number of particles (photons) as well as a wave (which on the face of it is something that seems impossible and logically contradictory) perhaps the universe (although probably NOT the biosphere and the Gaia that it forms in interaction with "physical" planet earth) also may have a dual nature, that is, BOTH cyclical AND having an end rather than one or the other? And if that notion seems completely logically impossible is it any more logically impossible than many aspects of quantum mechanics which as we now know is also able to make some of the most accurate predictions imaginable?

      So perhaps just as (and it is typically attributed to Feynman but in fact it was said by David Mermin) once said to those who didn't understand quantum mechanics...(and no one really does at least not precisely WHY it works, but only HOW it works) the famous "Shut up and Calculate" perhaps we could say to those who don't know whether to adopt an Eastern philosophical stance or a Western one to the existence of the Universe (or Multiverse) and its beginning, life, and end, OR its cycles, we could just say: SHUT UP AND CONTEMPLATE (in the West) and SHUT UP AND MEDITATE (in the East). And where the two then may meet (in the deep theoretical recesses of quantum mechanics) (if they do) will then provide THE ANSWER. But in the meantime most of us would do well to either Contemplate or Meditate or more simply just take it easy and RELAX since what we think or even experience is not very likely to affect the outcome (at least not that one) one way or the other.

    4. You should chat with Ka sometime on the Diner Max. You would have a field day.


  3. Gaia is in her puberty.
    10 thousand years ago, Gaia was in their biggest amount of biodiversity, on their biggest amount of complexity (included the recycled rate of P, N, C etc., ever). There are many other parameters, not just the pessimistic viewed here, that show that Gaia is at the beguining of their life. Of course, probably after 5000 millions years she will die or disappear from the Earth.
    Universe history is one of increasing complexity (the same apply to Gaia). University create Gaia in only 10000 million years, but just one star like ours could life for 10 times more time...
    Bacteria stand alone for 2000 million years, then for another 1000 millions unicellular eukariotes increase the complexity and possibilities of Gaia. After other 500 millions years the pluricellulars came, and only some 100 millions years ago, life could sense emotions. It is obvious to me that complexity is increasing exponentially here, that humans are the last but not the end of Gaia history, and that in 500 millions years, Gaia could perfectly well overcome the solar luminosity (at present the albedo is 0,3, just think in an albedo of 0,6 (not in the paper of Von Bloh and others)).
    I read Asimov tale when I was 15 years old, and after then I think that complexity matters.

    Carlos de Castro

  4. "the present moment is unique in the history of the planet"

    Of course it is, just like all the other previous and future unique moments through all the same previous and future cycles. Just as any rendition of Bolero by Ravel is unique, yet also the same and different as any previous or future rendition of the same yet different music. Every moment is simultaneously unique (at various levels), and simultaneosuly cyclical (at various levels). No, no, no, no, no! It must only and ever be one, or the other, insist the Arrowists (say, perhaps, the Montauges), versus the Cyclists (Capulets, obviously, or fill in your own blanks): cue the same old but different biting of thumbs, hilarity, and death.

    (Gould's Time's Arrow, Time's Cycle is a handy read in this regard.)

  5. In 2001 Donald Korycansky proposed a way to compensate for the Sun's gradually increasing output: Nudge an asteroid into an orbit crossing both Earth's orbit and Jupiter's. Each Earth flyby, about once every 6,000 years, pulls Earth's orbit slightly farther from the Sun, and each Jupiter flyby recharges the asteroid. Do it right, and Earth remains habitable for another five billion years.

    1. Or we could screen the sun, or change the earth's albedo, or try any other number of tricks. I am not to worried about the "humans" of hundreds of millions of years from now figuring out a solution to these problems. Either we/they will have annihilated ourselves long before then, or we will be well on the other side of the singularity.

    2. You really need to do it right. A little mistake and BANG........



Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)