Vacationing on Venus Basic Geology Series Part 1
Guest post by Steven Goddard
Magellan radar imaged Venus – NASA Image
In some ways, Venus is similar to earth. It is about the same size as the earth, has a nickel-iron core, and has volcanic activity due to radioactive heating in the interior. But that is where the similarities end. Venus has some serious problems as a vacation spot – mainly that it is extremely hot and the atmosphere is a thick cloud of sulfuric acid, CO2 and other unpleasant chemicals.
So how did Venus get to be like that, and why is the earth different?
- Venus is closer to the sun, which makes it hotter and prevents formation of oceans due to excessive evaporation.
- Venus suffered a traumatic collision in it’s early days, which causes it to rotate very slowly and parallel to the ecliptic. This makes for long afternoons (thousands of hours long) which get extremely hot.
- Because of 1 and 2, Venus was never able to sequester CO2 in limestones like the earth.
For the last few billion years, volcanoes on earth have been spewing out the greenhouse gases H2O, CO2 and CH4, as well as, H2SO4, SO2, H2S, HCl and Cl2. If not for the oceans and limestone sequestration, we would have a very thick, hot acidic atmosphere like Venus which could not support life. Fortunately, temperatures and other conditions on earth were just right to allow huge volumes of CO2 to move into the oceans and precipitate carbonate rock layers, where the CO2 became sequestered. This makes earth the pleasant place which we all enjoy.
Wikipedia image – carbonate rocks in Italy, uplifted miles above sea level.
One of the oft stated concerns by the IPCC and others is excess CO2 from cement production, which involves heating carbonate rocks and has the side effect of returning CO2 to the atmosphere. Dr. Hansen and others have also suggested that periods of rapid warming in the past have been due to limestone formations being subducted into hot volcanic regions and losing their CO2 to the atmosphere.
But make no mistake, without the CO2 sequestered in limestone and other carbonate rocks, earth would be hot, toxic and probably unlivable – like Venus.
Some more detailed discussion here and here .
Part 2 will be a discussion of how fossil fuels fit into the picture.
Curieux (14:09:21) :
If it was true, then in the early age of earth, life could’nt apeared, too much CO2 then too much heat.
In fact, on Earth we had probably 100% CO2 with 30 bars pressure. And we had almost immediatly life. The clue is elsewhere.
The Sun was about 35% less luminous back then.
“Venus rotates very slowly. It takes 243 Earth days to complete one revolution, but only 225 days to orbit the Sun. This means a day on Venus is longer than a year! Venus also has a ‘retrograde’ rotation, meaning it spins in the opposite direction of its orbit around the Sun. On Venus, the Sun rises in the west and sets in the east. ”
http://www.liverpoolmuseums.org.uk/wml/spaceandtime/planetarium/solar-system/venus.aspx
I’ve wondered why Venus has no magnetic field, could it be long day length and lack of satellite????
James: your
Is this guy for real, or have I missed some updates in solar system history?
Its a new theory.
Click here for New Scientist Article
The lack of water in the atmosphere can be explained by solar influence or an impact. The supposed lack of water in the crust and revolution of Venus the reverse of the rest of the system; can be explained by an impact.
Apparently the difference in the Argon content can also be explained by a direct impact, along with the too few impact craters on Venus.
The author of the theory also suggest a proof; if a surface lander does not find water in the rocks, then its probably due to an impact. If there is water in the rocks, then there probably wasn’t an impact.
I always wondered about the huge difference regarding pressure on earth and venus, given those two planets are nearby matching each other in size and density. Venus is nearer on sun and so much hotter, thus one would expect that sun’s radiation provides more energy, resulting in gently pushing away upper atmospheric molecules. Is there a theoretical upper limit on athmospheric pressure, given a planet’s mass, radius and it’s distance from sun?
I have read somewhere, that venus is hotter also not exactly due to CO2, but due to it’s high atmospheric density. I would be well interested, if someone had undertaken the effort to simulate the radiation balance of venus or earth, assuming, e.g., N2 would amount to the equivalent of pressure of 90 bar on the surface of such a planet.
Gore gets his Venus baloghney from Hansen who started out at NASA studying Venus. I’ve never seen Hansen discuss the relevant differences between Venus and Earth, many of which have been discussed in the article and comments in this posting.
When people relate Venus to Earth they always leave out the difference in distance to the sun, Venus’ super rotating sulphuric upper atmosphere, the lack of a magnetic field which allows the solar wind to impact the atmosphere directly, the lack of water, no moon and etc. It’s AGW as usual, tell only a small part of the story while leaving out 70% of the relevant material.
This reminds me of how, despite his noted intelligence, Stephen Hawking engaged in a flight of juvenile science fantasy as he expressed concern that increasing levels of CO2 would result in Earth’s climate turning Venus-like. Why is it that everyone seems to be so fixated on atmospheric composition that all other factors are ignored in such a dismissive manner? Science seems to be intent on traveling down a Hollywood B-film direction with silly notions of horrific climate change being substituted for mutated giant insects. At least, when leaving the movie theater, the rationality of the light of day easily dispelled such silly notions being witnessed on the screen {the need for much higher levels of oxygen to support such creatures, anatomical impossibility in supporting such massive creatures, etc.}. Now we’re on a perpetual science fantasy journey of ten-year tipping points with disaster just around every corner while second-rate failed politicians are listened to with rapt worshipful attention as they spew science nonsense. Along the way we struggle with other equally philosophically weighty concerns, such as how many children should a single mom have or which celebrity is or is not wearing panties today or whose marriage is falling apart. Any species that engages in such acts of gross stupidity deserves the future it will get.
I think the speculation that Venus had a moon and that it suffered a traumatic collision are just that, speculation. I don’t really think it deserves serious mention since there is no way to ever know.
Steven Goddard (14:14:59) :
At greater than about 5,000 PPM (0.5%) CO2 starts having serious health impacts.
You get this stuffy feeling and start sweating easier. I had to test for it at the mines I worked for. 5000ppm is still an OSHA and MSHA working limit for 40 hours work week. It used to be far more lenient, so 5000ppm (.5%)isn’t that big of a deal.
at 1% you just won’t be jogging that far.
at 2% you’ll know something is up.
at 4% you are in trouble.
Your plants will love you, though.
Maybe Mercury was Venus traumatic moon moment that got away?
A couple of points to note.
1) Due to being closer to the sun, and the inverse-square law, Venus sees TSI at the top of its atmosphere 93% higher than earth does at the top of its atmosphere. That has to count for something.
2) The article http://www.newscientist.com/article/mg20126942.000-whats-the-point-of-being-warmblooded.html?full=true discusses the evolution of endothermy. It mentions in passing that…
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So what do the fossils say? For the ancestors of birds it appears that the switch to endothermy took place around 140 million years ago, at the start of the Cretaceous. This was the period when nitrogen-rich flowering plants were beginning to take over. Atmospheric carbon dioxide levels started to fall, largely because the more developed root systems of flowering plants weather rocks faster, a process that removes CO2 from the atmosphere. Over the Cretaceous, levels of CO2 halved, from about 10 times pre-industrial levels to around 5 times.
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So at the start of the Cretaceous, the CO2 level was 2900 ppm (YES, that extra zero belongs there!). A quick Google search of http://scholar.google.ca/scholar?num=100&hl=en&lr=&q=%2Bjurassic+co2+OR+%22carbon+dioxide%22&btnG=Search turns up literally thousands of hits. A list of some of the more interesting ones follows. They indicate that CO levels have been a lot higher in the past. Some of the articles and papers indicate Jurassic CO2 levels as high as 16-18 times pre-industrial levels. That’s right 5,000, yes *FIVE THOUSAND* ppm!!! And guess what…
– the earth’s temperature was a few degrees warmer than today
– there were no polar ice caps
– but the planet didn’t blow up
– earth didn’t cross some mythical “tipping point” and turn into a hellacious Venus-like death zone
– not only did plant and animal life survive, it thrived, and earth experienced some of the lushest ecosystems ever in its entire history.
Depite the fact that flora and fauna thrived at 3,000 or 4,000 ppm of CO2, the war mongers are going berserk as CO2 levels edge up to a mere 400 ppm. Does anybody here have access to IPCC models? Can they run them and get output for scenarios of 1,000, 2,000, 3,000, 4,000, and 5,000 ppm of CO2? Why hasn’t the IPCC been called to account for their broken models?
And now, a few URLs of papers and articles for your reading enjoyment…
http://earth.geology.yale.edu/~ajs/1991/04.1991.03Cerling.pdf
http://earth.geology.yale.edu/~ajs/1999/10.1999.01Ekart.pdf
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V61-4RBYD3J-6&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_version=1&_urlVersion=0&_userid=10&md5=e15a66fb18df9aa54e53be31c65644bf
http://jgs.geoscienceworld.org/cgi/content/abstract/152/1/1
http://www.nature.com/ngeo/journal/v1/n1/fig_tab/ngeo.2007.29_F1.html
http://www.gsajournals.org/perlserv/?request=get-abstract&doi=10.1130%2F1052-5173(2004)014%3C4:CAAPDO%3E2.0.CO%3B2&ct=1
http://www.agu.org/cgi-bin/SFgate/SFgate?&listenv=table&multiple=1&range=1&directget=1&application=fm06&database=%2Fdata%2Fepubs%2Fwais%2Findexes%2Ffm06%2Ffm06&maxhits=200&=%22PP21B-1675%22
And one more for good luck…
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Tanganyika temperatures follow Northern Hemisphere insolation and indicate that warming in tropical southeast Africa during the last glacial termination began to increase ~3000 years before atmospheric carbon dioxide concentrations.
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That’s right folks, temperatures strted rising *3,000 YEARS BEFORE CO2 DID*… oops.
http://www.sciencemag.org/cgi/content/abstract/1160485
Of course CO2 affects the atmosphere’s temperature. Without any CO2 in the atmosphere, it would be extremely cold here.
There almost isn’t any CO2 to speak of now… How would going to zero really affect the temperature by any measurable amount? .00038 compared to zero seems pretty trivial, and going from .00028 to .00038 (delta .0001) seems nearly as trivial. Using a 3°C delta per doubling of CO2 (hypothetically), what happens in reverse? If we’re at 15C now, it takes 5 halvings of CO2 to get to zero C, or 96 halvings to get to absolute zero temp (!). Try it yourself…
2^-n where n=number of times to subtract 3°C from 15°C (current temp) for n * halving the CO2 content. Multiply by .00028 or whatever CO2 level you like to see the resulting content. Extremely cold would be right, as you get to absolute zero with 3.5e-33 CO2 proportion… Going below that would presumably take earth’s surface temperature below absolute zero (!).
Not that I believe the expression holds much truth, even one time much less 96 times. The high feedback idea is pretty much shot full of holes by now, and too many other mechanisms are in play, but an interesting concept just for fun… I would do it in the other direction but I think that idea has been overplayed a bit already and leads to similarly preposterous results…
Venus get almost 2X more energy from the sun than earth does. The heating is mainly due to gas compression of the atmosphere. At the same atmospheric pressure and corrected to the same energy input, the atmosphere of venus is about 20 C hoter… but that is of course due to SO MUCH more CO2 than here on earth.
The atmosphere of Venus is so think that a probe does not need a parachute to land. They only need a parachute up to about an altitude of 25 km then it is free fall… slow fall! If you could survive the conditions, it would take hours to “fall” to the ground.
The equivalent pressure at the surface of Venus is like at about 1 km under water here on earth.
AKD (12:12:24) :
CO2 is an “unpleasant chemical”?
If it’s 97% of the atmosphere, pretty unpleasant.
DaveE.
[Steven Goddard (14:26:56) :
Of course CO2 affects the atmosphere’s temperature. Without any CO2 in the atmosphere, it would be extremely cold here.]
Without using the expressions “of course”, “scientific consensus”, “modelling”, “Wikipedia” or “debate over”, can you substantiate that?
Bearing in mind, that is, that we are talking about “significant” factors in comparison with things like albedo, convection, water vapour, and SITTING RIGHT NEXT TO THE SUN.
Leon Brozyna (15:07:12) :
‘Any species that engages in such acts of gross stupidity deserves the future it will get.’
Yes, but why take me with it?
DaveE.
“But make no mistake, without the CO2 sequestered in limestone and other carbonate rocks, earth would be hot, toxic and probably unlivable – like Venus.”
Doubtful, due to the other major differences between Earth and Venus, particularly that Venus is about 28% closer to the sun.
Something else may also be contributing an extra warming effect to Venus – an exotic form of C02: http://www.azom.com/news.asp?newsID=10230.
Bruce Cobb (16:20:27) :
‘Something else may also be contributing an extra warming effect to Venus – an exotic form of C02: http://www.azom.com/news.asp?newsID=10230.’
Or is this just the ‘get out clause’ for some alarmists?
DaveE.
The CO2 content at 300,000 times that of Earth is only about 20 doublings (or lets say 40C to 80C warmer) so conventional greenhouse theory would not explain the temperatures on Venus.
(And Hansen’s original climate model in 1972 was trying to explain the temperatures on Venus).
The sulfuric acid layer in the atmosphere provides more of a greenhouse effect.
The other explanation is simply “gravitational compression” which heats the lower layers of the atmosphere given its density and weight. This is the force which causes stars to heat up at their cores and finally generate fusion. This is also the force that makes the gas giant planets hot near their cores and as you move down through their atmospheres.
Jupiter is 10,000K as you get close to the core, yet there is no sunlight and no greenhouse effect there.
I have not seen any calculations for how much gravitational compression adds to Venus’ surface temperature (or the Earth for that matter which I assume is a non-zero figure).
Dr. Hansen and others have also suggested that periods of rapid warming in the past have been due to limestone formations being subducted into hot volcanic regions and losing their CO2 to the atmosphere.
This statement also needs to be called into question. Continental crust like limestone is too light to be subducted.
Reminds me of-Io the satellite of Jupiter…
Hmmm..
If we are at 97%+ absorbtion of what CO2 can absorb, a whole lot more won’t absorb much more. Mars is almost 100% CO2, and it gets mighty cold. Venus has a heck of a lot more atmosphere. That explains most of it. It also receives twice the energy from the big orange thing. Here we talk about a 1% change in TSI causing all h— to break loose, (sorry Lief, I know that doesn’t really happen) and Venus gets almost 100% more?
It ain’t so much of what’s there but how much is there. A thick enough atmosphere will act as a blanket. Doesn’t take a big increase in temp to evaporate all the water. With that gone, most of the chemical processes that recycle and regulate stop working. Take away the Earth’s oceans and ice caps, and we’ll have some serious problems. 2600 w/m^2 might do it, but I haven’t heard anyone predicting this.
Comparing Venus to Earth is like comparing the Detroit Lions to a subway train. Little in common and you don’t learn much from the process.
The reason why the small amount of CO2 in the atmosphere has a big impact on temperature is because there is a spectral SW band which CO2 absorbs that is not absorbed by H2O. The first few tens of PPM CO2 in the atmosphere have a large impact on temperature.
Matt,
Your point about limestone not likely to be subducted is well taken. Subduction zones tend to lie below the carbonate compensation depth, and drag heavy oceanic basalts down. Hansen made the claim in this paper
http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdf
Solid Earth sources and sinks of CO2 are not, in general, balanced at any given time [30, 47]. CO2 is removed from surface reservoirs by: (1) chemical weathering of rocks with deposition of carbonates on the ocean floor, and (2) burial of organic matter; weathering is the dominant
process [30]. CO2 returns primarily via metamorphism and volcanic outgassing at locations where carbonate-rich oceanic crust is being subducted beneath moving continental plates.
Sorry, the last post should say spectral “LW” band, not SW.
All of the planets with the exception of Venus rotate perpendicular to the ecliptic and in the same direction as their orbits. The fact that Venus orbits parallel to the ecliptic, slowly and in the wrong direction is pretty solid evidence that it has suffered a severe collision since it’s formation. How else could that have happened?
It is also believed that the earth’s 23 degree axial tilt may be due to a collision which which also formed the moon.
PaulM (14:03:42) :
As a science history hobbyist this is fascinating.
There is a fringe astronomy theory that includes electricity called Plasma Cosmology. According to this theory, Venus is the recipient of a large flux of electricity from the Sun and it is this that is driving the temperature.
Paul, thank you for supplying this provocative alternative to the “just so” story of how Venus got its heat.
The history of Sagan’s encounter with Velikovsky is a significant moment in the development of modern astrophysics. With all due respect, I suggest that Velikovsky may have been more correct than Sagan.
For those with open minds who want to follow the development of the idea that the heat of Venus is significantly an electrical phenomenon, here are some further resources:
“The Venusian atmosphere is very dry at 30 parts per million of water vapor. And the water decreases in abundance by an order of magnitude near the surface. This implies that the surface of Venus is sucking up water at a rate that would remove it from the atmosphere in a geological instant. This finding was so outrageous that some scientists were prepared to simply disbelieve the data! As Grinspoon remarked: ‘We had gone there, more than once, and demanded an answer, and all we got was a colossal riddle.’….
….The Electric Universe model provides a simple way of understanding the differences in atmospheric composition between Earth and Venus. But it applies to Titan as well, where more atmosphere puzzles were recently uncovered. Both Venus and Titan are young planets, related by birth.”
http://www.thunderbolts.info/tpod/2006/arch06/061031venusatmosphere.htm
“Twin footprints of electric currents from space are apparent at Venus’ south pole—counterparts to the footprints earlier discovered at Venus’ north pole….”
http://www.thunderbolts.info/tpod/2006/arch06/060717doubleeye.htm