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When Microbes Ate the Ocean

museumpeace writes "When /. discussed a story about microbes that could break down water as a hydrogen source, many commentors went off on a tangent joking about runaway germs eating the oceans. Now, prof Joe Kirschvink and students at CalTech propose that indeed, the worst iceage ever, which nearly ended life on earth 2.3 billion years ago, was the result of algae evolving the ability to break down water and flooding the atmosphere with oxygen. The absence of oxygen consuming organisms at that time is said to have lead to destruction of atmospheric methane which had hitherto warmed the earth. The professor concludes: 'We haven't had a Snowball in the past 630 million years, and because the sun is warmer now it may be harder to get into the right condition. But if it ever happens, all life on Earth would likely be destroyed.'"

23 of 425 comments (clear)

  1. Re:The first Slashdot troll post investigation by Hooya · · Score: 0, Interesting
    at the risk of getting my karma burned... mod this up!! one of the things i've found on slashdot is that it doesn't pay to offer up a different viewpoint. i have no complaints about rejected stories that i submited since they were crappy to begin with. on the other hand, i've noticed that when others post some pretty clever things but not necessarily affirming the /. mentality, they've been modded down.

    MS is evil!! -- my cheap shot at karmafying myself...

  2. Re:The first Slashdot troll post investigation by anon757 · · Score: 0, Interesting

    After doing my duty and modding this up... I would like to see a story on this. Let the community discuss moderation & see if there are better ideas than are currently in place.

  3. Re:Wow, someone actually agrees... by csbruce · · Score: 0, Interesting

    No, the issue is not with the 50-point cap, it's that you post a message the people mod up to say 5, and then some other people come along later and mod it down to 3. Through no fault of your own, if you were are 50 before, you're now at 48, even though your message is still modded up one point. It's the fault of the over-eager early moderators, something quite beyond your control. This has happened to me at least five times (though to 49). Rather than applying the mods individually, the net mod should be computed on a per-message basis.

  4. Re:The first Slashdot troll post investigation by Fitascious · · Score: 0, Interesting

    This whole -1 thing is screwed. I worked at Andover.net (now OSDN) back in January and Feburary of 2000. I was a contractor brough on board to help build the Slashdot cage at Exodus, in fact I wrote my name with a magic marker on the bottom of the Quad Zeon VALinux box that probably still runs the main Mysql DB. At the time I thought it was pretty cool to be involved with the whole open source scene...

    You know what I learned? I learned that most of the "Famous" and "Big Names" in the linux scene are attention starved name dropping weenies.

    It after my assigment at Andover.net ended that I realized the whole Open Source movement is over. Done with. There are way to many people with way to much ego. All of the linux people in charge of the project were too busy stroking their ego's and counting their stock options.

    I thank CmdrTaco and all the rest for a good 2 or 3 years of entertaining reading, but times have changed, there is no energy left here. Time to move on, Open source has been assimilated by Corporate Practices. I sincerely feel that all that was good about Slashdot, and to an extent the Linux fenomenon is over. This Thread just ended any hope I had left. Time to bring on the next fad.

  5. Re:The first Slashdot troll post investigation by warez_d00d · · Score: 0, Interesting

    Well said. Instead the editors seem to have decided to mod -1 the entire thread.
    Go fuck yourself, micheal!

  6. Re:The first Slashdot troll post investigation by canadian+troll · · Score: 0, Interesting

    This whole place is fucked, i remember when a link was posted with some Xbox pics, i posted a jap site with way better pics... i got modded down. Somebody had problems syncing a palm to windows XP, i offered solutions to the problems... i got modded down. This is shite!
    Just because my name is canadian troll, doesn't mean that everything i say is a troll.

  7. Black & White colours...like these times... by chanio · · Score: 0, Interesting

    Sorry if I am not good at understanding the whole context of english speaking. I enjoy just what I can understand. But I guess that intolerance and expectance of perfection are what are common things that are leading these times to this flat-black&white world. Everybody is afraid of getting their intentions of starting flying missinterpreted. So it is easier to follow the cattle and risk less. I propose to increase opinions, to be able to ask for votes to change things. Technical improvements must follow social ones
    Emperor Marcus Aurelius once said: "If you can't change people, you must endure them..." It is very easy to destroy what others build without the compromise of proposing something new in exchange. Less ideals and more actions! (if I break something it is fair to break something inside myself at the same time) Things must be hard for everyone during these days, aren't them?

    --
    Rwe obliged 2 save our future by choosing:O3 hole-greenhouse effect instead of accepting everydays gossip-nonsense chat?
  8. Re:The first Slashdot troll post investigation by BSD+is+dying · · Score: 0, Interesting

    If you disagree with the moderation in this thread, please take up posting in this discussion as a protest of what's going on here. I hope there's enough people who care to get that discussion among Slashdot's most active ones. That's on the page to create a discussion if you don't know.

    Sorry if it seems like I'm spamming this, but it needs to be done if the editors are going to wake up and conclude that what they did to this thread was wrong.

    --
    Post here to protest editor moderation.
  9. Terraforming and the beginning of life by loggia · · Score: 3, Interesting

    While this sounds pretty bad, it seems that this was nature's way of "terraforming" our planet. It seems these bacteria might be handy for naturally creating other worlds we can inhabit. After all, we already have organisms that breathe oxygen.

  10. Re:Correction by spikexyz · · Score: 5, Interesting

    Yes, See SLIMES (subsurface lithoautrophic microbial ecosystems) that exist deep in the earth *completely* disconnected from surface activity. They get heat from the earth's core and food from breaking down rocks; these would probably survive and in time could recolonize the surface.

    See: Wilson, E.O. The Future of Life, 2002

  11. Science is hard by ndansmith · · Score: 2, Interesting

    Determing the cause of a global freeze which we think happened 2.3 billion years ago has got to be pretty tough. Their actual article is not linked, so does anyone have a link or an idea about how they determined this?

    1. Re:Science is hard by Quadraginta · · Score: 5, Interesting

      I don't have a subscription to PNAS, so I could only read the abstract, but for what it's worth I think it goes like this:

      All the evidence seems to be geochemical, e.g. they look at the chemical composition of rocks of a certain age and, knowing the chemical reactions that produce that composition, infer the chemical composition and temperature of the atmosphere at the time. This is not unlike the way the Mars Rovers are using the chemical composition of rocks on Mars to acquire evidence for or against the prior existence of liquid water.

      They take for granted that everyone agrees there was a massive glaciation (the "snowball") at a certain time long in the past, and that the early atmosphere was reducing (high in methane, ammonia and water, low in oxygen and CO2), but underwent at another certain time, long in the past, and because of the evolution of photosynthetic organisms (the cyanobacteria), a fairly rapid change to an oxidizing system (high in free oxygen and CO2, low in methane and ammonia).

      What they suggest is that the two events are not unconnected. By discarding certain evidence and adducing other, they argue the two events may be close in time. Hence there might be some connection.

      The connection they suggest revolves around the facts that methane is a known powerful greenhouse gas, and the Sun was cooler in those days than it is now. I speculate they suggest the early Earth was unglaciated because large amounts of methane gave a strong greenhouse effect that compensated for the lower solar illumination.

      But then the evil cyanobacteria (cue Imperial March music) evolved and started producing free oxygen like crazy, which reacted with the methane to produce water and CO2. Away goes the methane, away goes the greenhouse effect (since CO2 is less effective as a greenhouse gas than methane), and the Earth plunges into the deepfreeze.

      Later, the Sun heats up a bit, so less greenhouse effect will keep the temps up, and also aerobic organisms start exhaling CO2 and farting a bit of methane, and all is once again serene.

      The "close call" is because if the Earth were further from the Sun, like near the orbit of Mars, then there wouldn't be any replacement CO2 greenhouse effect, because the CO2 would just freeze out as dry ice.

  12. I read that story... by phorest · · Score: 4, Interesting

    Definitely must be Vonnegut's Cat's Cradle!

    --
    God: When you do things right, people won't be sure you've done anything at all.
  13. Re:Breaking the Mold by rm999 · · Score: 2, Interesting

    As I understand it, you are saying we will destroy ourselves by changing the ecosystem and allowing previously insignificant but dangerous organisms to become significant and kill us off (normally I would have glossed over your poetic post, but it was modded as insightful so I read it more carefully).

    I don't really get how that will happen. Yes, I agree that we treat this planet pretty badly, but I think the planet and humans are tough enough to take it.

    You may have a point, though. Many scientists postulate that humans are currently creating a mass extinction, similar to what killed off the dinosaurs (see http://en.wikipedia.org/wiki/Holocene_extinction_e vent). IMO this is probably true, but not as bad as it sounds. Many of the species that are dying off are not important to the big scheme of things, and the complicated interweb of life will compensate. The mass extinction is sad, but probably won't be the end of humans.

  14. I wonder... (Mars climate evolution) by scotty777 · · Score: 3, Interesting
    Did this happen to Mars?

    The article points out that if Earth was a bit farther away from the Sun, then the Carbon Dioxide would have frozen out of the atmosphere, thus preventing that particular greenhouse gas from bringing on a subsequent warming period. Mars has almost exactly that situation. One or the other of the poles is always cold enough to freeze Carbon Dioxide out of its atmosphere. Too little greenhouse gas ==>>planet stays too cold==>> water permenantly locked up as ice.

    With the discoveries of the last couple of years we know Mars has lots of water and Carbon Dioxide, and Methane to boot! AND we know that temperatures permitted liquid surface water in the distant past.

    Is this reasonable? Could cyanobacteria have doomed Mars? anyone?

    1. Re:I wonder... (Mars climate evolution) by Quadraginta · · Score: 2, Interesting

      Now that is one interesting question, worthy of a back of the envelope calculation. Does the lower escape velocity of Mars (5 km/s) versus Earth (11 km/s) really doom Mars to far less atmosphere than the Earth?

      If we integrate the Maxwell-Boltzmann probability distribution of the speed of gas molecules from the escape velocity of a planet to infinity, we get the fraction of gas molecules that at any instant are going faster than the escape velocity. Presumably if this fraction is higher than some limit, a limit determined by the net influx of gas from cosmic sources, e.g. microcomet impacts, then the planet will lose the gas, over geological timespans.

      God knows what that limit is, but we might as well just run the calculation for Earth at a temperature of 300K and fiddle with the limit until we find the Earth losing its H2 and He but keeping H2O, the next heaviest gas, as well as N2, O2 and so forth. Then we can use the same limit with Mars' escape velocity to calculate the maximum surface temperature at which Mars can hold onto the various gases.

      I'll append the code itself as a comment to my own post, but the results I get are these:

      escape velocity = 5.00 km/s
      log10(escape probability) = -50.0
      gas -- max surface temp (K)

      H2 -- 25.8
      He -- 51.1
      H2O -- 230.3
      N2 -- 358.1
      O2 -- 409.0
      CO2 -- 562.5

      The mean surface temperature of Mars is about 200K, so this crude calculation suggests keeping water is iffy, but nitrogen, oxygen and CO2 are probably there to stay.

      On the other hand, the observation is that Mars has kept its water. Now, water is the lightest of the interesting common gases in Earth's atmosphere (N2, O2, H2O and CO2). That fact suggests Mars should have no more trouble holding onto a nitrogen/oxygen atmosphere than the Earth does.

  15. Re:it couldn't happen again... by drerwk · · Score: 2, Interesting

    Evreything is indirectly solar power.
    you forget radio nuclide decay heat...currently estimated to be about 1/2 of the heat in the earth.

  16. we are in an ice age now!!! by cdn-programmer · · Score: 1, Interesting

    For about 80% of the last 540 million years the earth was about 10C warmer than now. We are presently in an ice age.

    The earth was completely frozen over about 1 billion years ago and this ice age lasted probably about 1/2 billion years. Most likely it waxed and waned. When the oceans are completely frozen over they cannot absorb CO2 and the levels build up to over 100x what they are now. This is the change that the paleoclimate shows is required to lift the temperature enough to start thawing the oceans. By looking at this we can see the global warming folks are out to lunch.

    In any event - the CO2 is released by volcanizm and these processes continue even though the planet is frozen over. When the levels get high enough to melt the ice then the CO2 starts to be absorbed and ends up in the carbon sinks. This can cause the earth to tip back into an ice age and the oceans can freeze over again.

    Mixed into this equation is the role of water vapour. When the earth is fozen over - there is effetively no water vapour in the atmosphere. If one looks at the ABSOLUTE HUMIDITY CURVES one can see that below zero there is effectively no water vapour in the atmosphere. This is why it is so cold at the top of mountains.

    So - as the oceans freeze over then the H2O in the atmosphere is also lost which accelerates the cooling of the planet.

    At the present moment the earth would have to freeze down to near the tropics in order to flip us into a completely frozen over ice ball. There is enough water vapour especially in the humid sub tropics to trap enough heat that this is quite unlikely.

    However it is very likely that we will see the advancing of another period of glaciation because there have been about 20 or so in the last 2+ million years.

    This being said - eventually our current ice age will end and the planet will warm up about 10C. When this happens the poles will lose their ice caps - water vapour will form at high latitudes and lock the planet into a warm period which in the past has lasted typically for million of years.

    The reasons for this are not completely clear. Dr. Tim Paterson from Carlton University has published that the orbit of the solar system in the galaxy may be the driving factor. The theory is that cosmic radiation increases the cloud cover which reflects energy thus cooling the planet.

    It is also likely that the amount of land at high elevation is a significant factor. The earth was much warmer 30 million years ago than now. At that time we did not have the high Denver Plateau - the Tibetain plateau and most of our modern mountains such as the Rockies, Pyrenees, Alps, Andes, Himilaian and hellenic ranges were not formed.

    Land at high elevation reflects energy into space - which is why you can freeze to death at the top of mount Everest for instance in spite of the fact it is in the subtropics and it is the middle of May. Furthermore the cold scrubs the water vapour.

    At low elevation water vapour functions as a fairly effective blanket and furthermore in the tropics for instance at 40C it will be in concentrations of over 70,000 parts per million (eg 7%).

    Water Vapour in fact is the 3rd most abundant atmospheric gas.

    Compare this to the CO2 levels of 370 PPM.

    If we were to increase CO2 levels by over 100x then we get CO2 into the range of 37,000 ppm and that this level it can do the job that water vapour is doing now. Note that at 19x it cannot. This is proven by the Ordovician ice age where in spite of CO2 levels between 13x and 19x greater than now - the earth cooled by about 10C and an ice age similar to what we have now developed.

    At this time we also had a period of mountain building: The Taconic Orogeny.

    One last point. Most of our global warming folks are looking at data that goes back no longer than human history. While this may seem to be a long time - it is not significant.

    If one were to map the pages of the Encyclopeadia Britannica to the last 540 million years

    1. Re:we are in an ice age now!!! by Latent+Heat · · Score: 2, Interesting
      Sorry you got modded troll -- maybe you can get some justice in meta-moderation.

      I guess I am going to "troll to your troll."

      The point of the Mann "Hockey Stick" is not so much as that there were warm and cold periods in the past beyond the horizon of human history. The point is that the climate has been dead flat for 1400 years and only in the last 100 or even 50 years has the climate warmed, suggesting an anthropogenic source. The other part of the Hockey Stick is that the Medievel Warm Period and Viking Greenland colony days were local and not global effects.

      Trouble with the Hockey Stick is that the times past data is from tree rings and other proxies and has really big error bars. The recent past data is from meteorolgical temperature records with all of the attendent problems of heat islands and the like. The reason you don't do proxies for the recent past is that the numbers would be all over the place and wouldn't show the blade of the Hockey Stick. The reason you smooth the heck out of the proxy data is that, well, they are so noisy.

      Then you have those two Canadians who pointed out that the flat part of the Hockey Stick may be an artifact of data handling, but, wouldn't-cha-know-it, the Canadians are not climate scientists, so we can safely disregard everything they point out.

      Apart from the Hockey Stick, there are the climate modelers. I believe that their deal is that yes, water vapor is the main greenhouse gas, but the tropics are at 100 percent humidity anyway, so you won't get any more of it, so CO2 is the "swing vote on the court" if you will. They are also assuming strong positive feedback mechanisms -- is it that warming will release more CO2 from reservoirs? Is it that warming will release more H2O at higher lattitudes. I am kind of shakey on that part.

      You know, I have heard it argued that it is not entirely clear that the rise in CO2 is anthropogenic. Yes, CO2 is rising as we cut down the rain forests and burn fossil fuel, but at only half the rate, and the rest must be going into sinks. Or maybe the sources and sinks are the dominant effect, and the increase in CO2 with civilization may only be correlative and not causitive. But there are an awful lot of people who are sure of themselves.

  17. Re:Modern myth? by jzylstra · · Score: 2, Interesting

    According to what I learned in college: "If oxygen were to reach a value of 30% of atmospheric gas composition, fires would occur whenever a lightning bolt hit humid vegetation."
    http://www.globalchange.umich.edu/globalchange1/cu rrent/lectures/Gaia/#EXAMP

    So there is some truth to that.

  18. typical wired pseudo-journalism... by tongue · · Score: 2, Interesting

    This is what happens when consumer journalists are allowed to write stories about real science.

    Newsflash: nearly all autotrophic life on earth (read: photosynthetic life, commonly known as plants) breaks down water when it creates glucose. Basically what the students have figured out is that cyanobacteria came up with a significant part of the chemical reactions that just about every plant on earth uses now, rather than those reactions evolving further down the chain.

    The fact that this occured isn't new. at all. originally it was thought that the O2 that plants make came from the C02 they take in, but it was demonstrated quite some time ago that the plants actually split water and use the oxygens from that for the 02.

    conclusion: cnet writers are idiots.

  19. Re:Correction by The+Fun+Guy · · Score: 2, Interesting

    We're deeply offtopic here, but if you take a look at the title of that day's webcomic, it reads "Episode 476: Red Mage in the Cradle", obviously a reference to the book "Cat's Cradle" by Kurt Vonnegut. This novel, written in 1963, is where Ice-9 is orignally introduced as a theoretical form of water which solidifies at room temperature, and is thermodynamically preferred over normal ice. Since contact with it would cause all water everywhere to solidify instantly, Ice-9 has the potential to freeze the world solid, therby killing just about everything on Earth in the blink of an eye.

    The book revolves around the pursuit of a small vial which may or may not contain a small piece of this incredibly powerful, incredibly dangerous substance, created by a very clever rogue scientist who didn't bother to consider the consequences of his actions. Written at the height of the Cold War, Ice-9, of course, is a stand-in for nuclear weapons... a technology which everyone wants to have, everyone wants the other side to *not* have, but one which, from a tactical standpoint, has no pratical application, since it can't be used without terrible consequences for all sides.

    --
    The man who does not read good books has no advantage over the man who cannot read them. - Mark Twain
  20. Re:Cold at top of the mountains by cdn-programmer · · Score: 2, Interesting

    You are partially correct. The cooling at the top of a mountain is due to the expansion of the air at high elevation. This takes energy and the energy is lost as heat.

    However the trapping of the energy at the top of a mountain is what I am talking about. There is a greater amount of solar energy at the top of a mountain that at the sahara dessert for instance. This can easily be seen. The air absorbs solar energy. The solar constant in orbit is about 1.3 kw/m^2 and at sea level it is about 1.0 kw/m^2

    The difference is what is absorbed by the atmosphere. And these numbers are from memory.

    At the top of a mountain you have two processes working:

    1) the energy is reflected back into space
    2) there is not much up there to trap it

    The lack of water vapour at high elevation is a critical factor. Get rid of the mountains and you have a number of factors that work together to warm up the planet.