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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.'"
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.
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
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?
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.
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).
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.
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_
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?
Evreything is indirectly solar power.
you forget radio nuclide decay heat...currently estimated to be about 1/2 of the heat in the earth.
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
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."u rrent/lectures/Gaia/#EXAMP
http://www.globalchange.umich.edu/globalchange1/c
So there is some truth to that.
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.
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
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.