Water, not CO2 - Bad for terraformers?

soph · 2003-03-23 19:37:50

So why not use CFCs? We know we can produce them.

Josh Cryer · 2003-03-23 19:59:30

Search Google for ?carbon cycle? and ?energy pyramid.?

There are some things I don't think are issues, though, like the southern hemisphere being relatively dry. This could be accommodated by canals. Mars' southern dryness would just be the charm of Mars. Hoping to completely terraform Mars, to be in a state like Earth, is a difficult dream to realize, but making Mars so that one can run around without a suit on, isn't so much, in my humble opinion.

How many nitrate rich comets or asteroids would it take to increase Mars' atmosphere a few hundred milibars?

Shaun Barrett · 2003-03-23 20:07:10

BGD's and Soph's argument is flawed in that neither one of them noticed the error in the CO2 concentration figures for Earth's atmosphere. It isn't >1%. It's only 0.03%.
E-C's point about the Earth's eccentricity is true: Earth is at aphelion during the northern summer and at perihelion during the northern winter. The difference in actual distance, of about 3 million miles, has virtually no effect on the surface temperature compared to the Earth's inclination of 23.5 degrees.
By coincidence, the northern summer on Mars also occurs at aphelion (at the moment). The eccentricity of Mars' orbit is considerably greater than Earth's and this will have some effect on the maximum temperature differential between the northern and southern hemispheres of a terraformed Mars. But, once a thick (500 millibar) CO2 atmosphere is established - if that is possible - with super greenhouse gas additives, the overriding factor in seasonal temperatures will again be the planet's eccentricity (25 degrees). The winter hemisphere will be cold, but not intolerably so.
BGD's comment about producing 1 mb of super greenhouse gases in the Martian atmosphere being impossible for at least 300 years may or may not be true. But the fact is, nobody is suggesting that that much of it is needed. Super greenhouse gases have an astounding effect on global temperatures even in microbar amounts. Dr. Robert Zubrin, in his book "The Case for Mars", has outlined the kind of gases required, the quantities, and the production schedule to maintain their presence in the Martian atmosphere. None of this is impossible by any means.

The comment about any future Martian ocean being in the northern hemisphere is well taken. This potential problem has been discussed elsewhere in New Mars - with particular attention to the fact that Oceanus Borealis will be centred on the north pole. Personally, I don't think this aspect of terraforming has been adequately dealt with and could cause considerable trouble unless a way is found to prevent the ocean freezing. A soletta devoted specifically to this task has been suggested and may be the only solution.
Converting the entire atmosphere to an Earth-like one which we could breathe takes the whole problem to a new level of complexity due to the loss of all that CO2 and its greenhouse warming effect. But that's a problem for the next thousand years, in my view, and I'd be happy with CO2 for the time being!
(I'll even settle for domed habitats for now - if they'll only get started on the project before I die!! I think that's Dicktice's line of reasoning, too. )

RobertDyck · 2003-03-23 23:37:37

Hey! Actually discussion of terraforming by people who can quote numbers. However, it sounds like BGD has not read "Terraforming: Engineering Planetary Environments" by Martyn J. Fogg. Use of Perfluorocarbons can very significantly increase the temperature on Mars.

I argue for PFC's rather than CFC's because CFC's break down ozone. The goal of terraforming is to walk on the surface of Mars with no environmental suit, or at most an oxygen mask. That means UV radiation must be within tollerable levels. If you build an oxygen atmosphere, the UV light itself will combine molecular oxygen (O2) into ozone (O3). UV will also destroy ozone into O2. As long as you don't do anything to destroy ozone, the creation and destruction processes will balance at an equilibrium. I believe the equilibrium shall result in a UV level on the surface of Mars that is the same as Earth. That means you don't have to do anything to create protection from UV, you just have to create an oxygen atmosphere and ensure you don't destroy ozone. CFC's destroy ozone, PFC's do not.

According to page 238 of the book Terraforming, the estimated average resident time of CF4 is >50,000 years, for C2F6 it is >10,000 years, C4F10 is >2,600 years, C5F12 is 4,100 years, C6F14 is 3,100 years, c-C4F8 is 3,200 years, (CF3)2c-C4F6 is 2,900 years, and for SF6 it is 3,200 years. I think these times can be considered effectively permanent. If humans still live on Mars after that time, they can replenish the PFC's in the atmosphere.

RobertDyck · 2003-03-23 23:55:22

One discussion we had on the original message board regarded pressure. I argued we don't need to increase Mars surface atmospheric pressure to 1 Earth atmosphere. The partial pressure of oxygen on Earth at sea level is 3.0 psi. That means humans could breathe pure oxygen with an oxygen mask on the surface with a 3.0 psi (212 mbar) pressure. Humans can also acclimate to lower pressure. It takes weeks of high altitude training, but it takes months to get to Mars. You can breathe 2.5 psi (172 mbar) of pure oxygen after acclimation, and can even endure 2.0 psi for a short duration. So raising the Mars surface pressure to 1 Earth atmosphere, or 14.69 psi (1013.25 mbar) is not necessary.

Creating an atmosphere you can breathe without an oxygen mask is a little trickier. Pure oxygen at 2.5 psi is not as flammable as pure oxygen at 14.69 psi, but you still want a moderator. Furthermore, plants require CO2 and a nitrogen source. Nitrogen may be more efficiently delivered directly to plants as nitrate fertilizer rather than a gas, but that still leaves the requirement for CO2 and a moderator.

Shaun Barrett · 2003-03-24 02:35:44

Yes, Robert.
The scenarios you describe are, of course, all feasible. Even the 172 millibar O2 atmosphere, with CO2 reduced to 1 millibar for human consumption purposes, is marginally acceptable as far as temperature maintenance is concerned. I put these figures into Martyn Fogg's Terraforming Simulator, with CH4 set at 5 microbars, NH3 at 50 microbars, and CFC at 2 microbars. (I understand that CFCs are NOT desirable for the reasons you mentioned - but ignoring that for the sake of argument). With the above atmosphere, and making no alteration to albedo or insolation, the projected temperature figures came out:-
Mean global +4.5 deg.C
Polar -35.1 deg.C
Maximum tropical +32.2 deg.C
The planet would be above freezing at latitudes up to 37.7 degrees. Using this as the theoretical boundary for settlement (an arbitrary boundary), this makes 61.2% of the surface habitable.

But, as has been pointed out, producing such an almost totally O2 atmosphere - even if that were the desired outcome - may not be achievable in the short term. It seems more likely, at least with our present understanding of the volatile inventory, that a chiefly CO2 atmosphere might be easier to create.
Using the same simulator, a 400 millibar CO2 atmosphere, with the same partial pressures of greenhouse gases quoted above, would be considerably warmer:-
Mean global +13.6 deg.C
Polar -11 deg.C
Maximum tropical +42.2 deg.C
Producing a surface above freezing up to latitudes of 59 degrees and making (arbitrarily again) 85.7% of the surface habitable.
As Dr. Zubrin explains, although we would need domes over our settlements with such a poisonous atmosphere, they could be made very large since there would be little pressure difference between inside and outside and massive foundations would be unnecessary. The atmosphere inside could be 50% oxygen and 50% nitrogen, producing a very Earth-like O2 partial pressure of 200 millibars.

I still think a soletta will probably be necessary to prevent freezing of any large bodies of water in the northern lowlands. Such freezing would produce large areas of ice with a corresponding increase in albedo and greater reflection of sunlight. A runaway refrigeration effect would follow.

[P.S. I think BGD might be confusing millibars with microbars. 1200 millibars of NH3 would probably raise the average global temperature on Mars above the boiling point of water!]

Shaun Barrett · 2003-03-24 05:03:12

No, BGD! please don't hide under your box!
Terraformation IS definitely for you!! It's for anybody who's interested in it.
Your knowledge of the details in this subject are an indication of your interest in it - and we need all the help we can get!! Sometimes, because of my passion for this topic, I can tend to be overly particular about small points. If I have seemed too critical, I didn't mean to be (indeed, with the gaps in my own knowledge, I cannot afford to be! ).
I, for one, look forward very much to hearing more of your opinions on what, to me, is one of the most fascinating and absorbing of concepts.

RobertDyck · 2003-03-24 08:16:19

BGD,
Check out Martyn Fogg's tarraforming web site called the Terraforming Information Pages.
If you are interested in the book, you could order online at Chapters.ca, it can be sent anywhere in the world that mail can be delivered. I believe it is currently out of stock, but check later or ask the book store to get a copy for you. This is a Canadian online book store, so prices are in Canadian dollars. If all else fails, send an email directly to the author. He may be able to locate a copy for you. His email address is on his web site.

dickbill · 2003-03-24 11:14:55

Hi all,

Interesting thread. I think that the relative lack of CO2 wil make the terraformation more difficult of course, but not impossible. As you all mention, we will have to rely more on chlorofluorocarbon, preferably PFC.
take a look at PNAS online:

"Proc Natl Acad Sci U S A 2001 Feb 27;98(5):2154-7
Keeping Mars warm with new super greenhouse gases.
Gerstell MF, Francisco JS, Yung YL, Boxe C, Aaltonee ET.
Division of Geological and Planetary Sciences, MS 150-21, California Institute of Technology, Pasadena, CA 91125, USA.
Our selection of new super greenhouse gases to fill a putative "window" in a future Martian atmosphere relies on
quantum-mechanical calculations. Our study indicates that if Mars could somehow acquire an Earth-like atmospheric composition and surface pressure, then an Earth-like temperature could be sustained by a mixture of five to seven fluorine compounds. Martian mining requirements for replenishing the fluorine could be comparable to current terrestrial extraction."

Fluor is abundant on Mars and so PFC could be produced, as they mention, but how many PFC factories would have to be installed to produce a significant amount of those gaz in just several decades ?
So i thought again about using the microorganisms metabolism. I searched in pub med for an organism which could produce PFC or homologues as a result of any metabolic waste, by product or intermediate metabolite, but I found nothing.
Fluor is the ultimate poison. It is generally an inhibitor of enzymatic reaction. In short, life doesn't like fluor. But so was O2 just after the anaerobic phase of life on Earth. So maybe it's gonna be possible to produce by genetic manipulation a though lichen symbiot which at one metabolic step could produce and wisthand a PFC gaz, that would certainly be a great leap in the Mars terraforming project.

Bill White · 2003-03-24 12:31:17

So, the difference on Earth is 6.69%, while on Mars is 26.66%. But this is directly proportional with the temperature, so while on Earth there are variations no bigger than 6.7% (actually are lower because of our oceans, which trap heat), on Mars could go to as much as 26.66%.
The conclusion is yours.

The role of our oceans as "heat sink" and climate buffer brings us back to global warming on Earth and the role of ocean currents in transporting heat to the northern hemisphere from the equatorial regions. Mars lacks such heat transport mechanisms. Perhaps Mars is more amenable to terra-forming than I currently believe or perhaps Earth may more readily become uninhabitable with fairly modest swings in long term climate patterns.

Warming Mars up may be easy enough - keeping Mars within a range of temperatures suitable for growing plants in the open will be another challenge altogether.

RobertDyck · 2003-03-26 12:44:17

The book "Terraforming: Engineering Planetary Environments" by Martyn J. Fogg was also published in 1995. The Terraforming Pages by Martyn Fogg includes one page super greenhouse gas analysis which gives some details about PFC's. That page was written in 1999.

The average resident times I quoted are for Mars. There is also a chapter on terraforming Earth, but I quoted from the chapter about terraforming Mars.

Auqakah · 2003-03-26 17:29:47

This latest "let's run Mars down" thing gets more and more interesting all the time.
As you all know, we've had one or two pessimistic articles about Mars just recently. You'll remember the finding that the south polar cap is mostly water ice (see above, in this thread), which caused tut-tutting about the negative implications for terraforming - miles and miles of water but no CO2 to build an atmosphere! But nobody bothered to point out that it was always going to be the regolith, much more than the polar cap, which would provide the bulk of the CO2 - a very convenient omission!

I noticed that, too (elsewhere, as I haven't posted here for a while), about the 'tut-tutting about the negative implications for terraforming...water but no CO2 to build an atmosphere', and found it very strange. I especially noticed that Reds were remaining silent on it, mostly because it was the usage of the regolith for CO2 that is most destructive.

Personally, despite being a Red myself, I don't see how less CO2 poses a problem. Quite the opposite; some people have wondered just what the devil to do with the CO2 once the atmosphere has been thickened appropriately.

And hasn't the real problem /always/ been the (I'll say apparent just in case things change again) apparent lack of nitrogen?

soph · 2003-03-26 19:18:02

I think the issue is we don't know the quantity of nitrates that exist. I've heard speculations of nitrate beds, and speculations of a complete lack of nitrogen.

That's right, I meant <1% CO2, typo.

Digital_Wolf v.2 · 2003-06-15 12:09:38

just get a bunch of cars and turn them on. you might have to leave them on for a while though.

Echus_Chasma · 2003-06-16 00:06:17

That'll take a lot of cars. :laugh:

But cars produce carbon monoxide... does anyone know if carbon monoxide is a greenhouse gas?

By the way, welcome to the New Mars forums dude.

Tyr · 2003-11-20 17:34:40

How badly do we really need nitrogen?

mbastion · 2004-05-31 01:52:46

Hi,

I agree with BGD on a lot of what he's said, except Mars can't be terraformed.

>Use of Perfluorocarbons and CFCs

is fricken stupid! They are atmospheric pollutants (irritants) that humans can't be exposed to.

>The goal of terraforming is to walk on the surface of Mars

No, it's not! It's to make a planet earth-like. Stop redefining the word "Terraforming" to suit your own flawed fantasy. Mars can't be terraformed.

>"Terraforming: Engineering Planetary Environments" by Martyn J.
>Fogg.
>According to page 238 of the book (of FOGG)

It's not a BIBLE for fricks sake! The book is 9 years old and written by a former dentist.

When will you Pro-Mars people finally realise your fantasy is flawed. Mars can't be terraformed. It's not possible, it won't happen, and anyone that tries will fail.

Check out "Why Mars can't be terraformed":
http://www.geocities.com/alt_cosmos/why … ymars.html

from my website:
http://www.geocities.com/alt_cosmos/ind … index.html

Michael

Rxke · 2004-05-31 05:17:55

Hereby i declare mbastion the most unpopular member on the NewMars messageboards! :;):

(Kidding, kidding!! Seriously: a warm welcome, interesting site you have, raising *good* points..)

-Some questions, remarks:

*'terraformation:' why are you so irritated by the term being used 'uncorrect?' a lot of scientists have been using the term "partial Terraformation" for a while now, so it's gotten a firm footing in the English 'tech-speak.'
Arguably it *is* uncorrect, sloppy use of terminology, but, sigh... I'm afraid we're stuck with it, so... At least it's not as bad as the confusion with the term 'nanotech', wich could mean *a lot* of wholly different, arguably unrelated things...

*Mars (and a lot of other planets/bodies) can't be terraformed(or partially) because of the low gravity you say... (escape of H, H2)
Hmmm... But did you consider the possibility of 'constant' boosting the atmosphere with extra-planet sources (like ice-comets grazing the upper layers etc...)
But how fast does Mars, Titan etc. lose it's H? If it is slow enough, it could be possible to use said counter-measures.

I've read the "why it is not a good idea to use ice-comets " entry on your site, good point, but then again: how fast would the atmosphere deteriorate? Coccolithophores, for instance, could sequester the rising CO2 if its rise was gradual etc...

Finally, i saw you read a lot of SF. So i want to tickle you with a favourite saying of A.C. Clarke: (probably poorly cited, i'm bad at citing other people...)

"When a scientist says something is impossible, he's very probably wrong"

Heehee...

Shaun Barrett · 2004-05-31 07:16:23

I don't understand what you're trying to say, MB.
Reading some of the stuff in your website, it appears you're telling us that Earth only has water at its surface because its gravitational acceleration is sufficient to retain hydrogen in the atmosphere. You go on to say that Mars has insufficient gravity to retain hydrogen and therefore can never have surface water. Therefore, terraforming Mars is impossible.
I have a problem with your assessment.
Firstly, Earth can't even retain helium-4 with its gravitational field, never mind lighter H2 molecules. (Trace quantities of helium in Earth's atmosphere come from radioactive decay processes in our planet's crust and mantle, which produce alpha-particle radiation - an alpha-particle simply being a helium nucleus. All Earth's primeval supply of helium was lost to space long ago.) Experiments have indicated that Earth is indeed losing hydrogen as water molecules at high altitudes are dissociated by UV light. But the point is that the process is slow. If present rates of hydrogen loss are typical of losses over Earth's 4.6 billion year history, then we've lost the equivalent of just 1 metre of water from our oceans in all that time!
My point is that Earth is hardly any better at retaining hydrogen than Mars is, if gravity is the only criterion.

Admittedly, Mars has disadvantages in retaining volatiles when you compare it with Earth. The martian gravitational field is indeed only 38% the strength of Earth's, so loss rates of many gases must necessarily be faster. In addition, Mars lacks an ozone layer, which means the UV flux is higher throughout the atmosphere - even down to ground level. This must in turn result in higher rates of dissociation of water molecules and consequently higher rates of hydrogen loss. The above problems are exacerbated by the lack of a global magnetic field, leaving most of the upper atmosphere unprotected from volatile losses due to 'sputtering' by the solar wind. (One advantage Mars has, though, is its lower insolation due to its greater distance from the Sun. The resultant overall lower temperatures tend to slow gas molecules and thus make them easier for Mars to retain.)
The disadvantages I've mentioned may rightly be cited as impediments to the permanent long-term terraforming of Mars, but implying that Mars can never be like Earth because Earth can hold on to hydrogen, while Mars can't, is simply not true. Earth cannot retain any significant quantity of hydrogen for any significant length of time either!

The problems for Mars and its volatiles, which I've touched on above, nevertheless remain. And it's true to say that if we create an atmosphere and an Oceanus Borealis on the Red Planet, and if efforts are not undertaken to maintain them, the atmosphere will escape and the water will be frozen again into the crust.
But the process will be very slow, by human standards. Calculations have shown that a dense atmosphere on Mars would take on the order of 10 million Earth-years to leak away.
For a species only 200,000 years old, 10 million years is a very generous time interval. By the time our terraformed Mars is showing signs of reverting to its former freeze-dried self, we humans will be either extinct or will be possessed of almost God-like technology. In either event, we won't care about volatiles escaping from Mars!

I have to say, MB, I don't agree with your analysis of the situation at all. Terraforming Mars is not only possible; I believe it will be done.

mbastion · 2004-05-31 20:34:55

Hi,

>*'terraformation:' why are you so irritated by the term being used
>'uncorrect?'

Debate. I want people to logically and scientifically argue the possibilities of terraforming. I want to know what is and isn't realistically possible. If someone has a point they should be willing to debate the issue and prove their point. If someone can't prove their point without quoting sci-fi novels or if they're just reiterating someone elses ideas then don't bother, it's all been said before. Equally don't try to prove a point by saying "god will make it happen", this is not the domain to air religious views.

If you believe Mars can be terraformed then prove it, with your own proof, in your own words. When someone disagrees with you, argue the point, don't just say "nah you're wrong" or "Kim Stanley Robinson said so".

It's very irritating, very frustrating, when someone can't argue a point and so they redefine words and play with semantics to push their point across, even though they know they could be wrong. Use the proper meaning of words and the correct nomenclature.

>did you consider the possibility of 'constant' boosting the atmosphere

Yes. We don't do that now with earth, so to do that to another planet would not be earth-like, which is the point of terraforming. The need to constantly prop up a planets atmopshere is proof enough the system has failed.

>But how fast does Mars, Titan etc. lose it's H?

How fast they loose Hydrogen NOW is not the issue. How fast they WILL loose Hydrogen, if you try to terraform them, is. With low gravity, the answer is: quickly. I'd like to argue this point further with figures but I am still putting an accurate model together. I'll respond again when I have some figures for you.

>"When a scientist says something is impossible, he's very probably
>wrong"
I don't believe I have ever used the word impossible (if I have, let me know). I've said it can't. The amount of additional mass that will need to be added to Mars for it to hold Hydrogen is greater than Mars itself. Hence, the final product can't be called "Mars" as the name of the larger mass is dominant. Nomenclature aside, you can't bury the surface of Mars under 640km of solid iron and still call it "Mars". "Mars" is the name of the current planetary mass, not an orbit.

>it appears you're telling us that Earth only has water at its surface
>because its gravitational acceleration

That's a generalised summation but not exactly what I said.

>Earth can't even retain helium-4 with its gravitational field

I disagree. Please prove it. Use equations if you need to.

>if gravity is the only criterion

It's not, you should read my webpage more carefully.

>implying that Mars can never be like Earth because Earth can hold on
>to hydrogen, while Mars can't, is simply not true.

I wasn't implying, it was a statement, it can't. If you think otherwise please prove it, don't just say "is simply not true".

MB1
http://www.geocities.com/alt_cosmos/ind … index.html

Rxke · 2004-05-31 22:30:05

mbastion, thanks for the replies!

Now, before we go off into an endless discussion, considering Terraformation can't be done w/o mass adding etc...

BUT some stubborn people *still* want to change Mars etc. to *more or less* Earthlike conditions, so you for instance would only have to wear a facemask..

How does one call that process? And are you opposed to things like that? Because it would not be a stable situation, needing constant tweaking etc.

I can understand your frustrationn with the non-scientific babble about the subject, but most people here are just purely amateurs, willing to learn (most of the people, i'd think)
Like in the propulsion-related sections: wild ideas, being corrected by people that *know* physics etc...

I'm really sincere saying i'm very happy with your input, so please have a bit of patience with us 'dreamers...'

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