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Global Warming Mostly Confirmed - On Mars
dinotrac writes "A just-completed 23 month study, carried out over the course of a Martian year, found that the Martian polar ice caps are rapidly eroding, sending large amounts of the greenhouse gas carbon dioxide into the Martian atmosphere. If this pattern continues over time, Mars could go from a planet whose winters are cold enough for dry-ice snow to having a shirt sleeve atmosphere. Humans would still have to provide for oxygen, but plants could go naked.
I wonder if this means tougher emission controls on the next Martian rover?"
This really shouldn't affect local global warming theories. After all, it's only been 23 months, and its the only data we have. We have no real historical record the way we do with earths temperature. (both with ice-cores and with recorded history).
And, earth and mars, obviously, have vastly different atmospheres.
The fact the temperature on mars increased slightly over the past 23 months doesn't actually change anything with regards to mans affect on the earths atmosphere. We already know that earth can change without us, it has in the past.
What we need to find out is how much (if any) effect on our climate we actually cause.
autopr0n is like, down and stuff.
recently overhyped global warming debate ?
I must say I find the accussation that Global Warming is over discussed, hyped, etc... bemusing. To me FOOTBALL is overhyped, CELEBRITY is overhyped, the WEATHER is overhyped- each of these are covered in every news bulletin in the world, every day.
Until people generally have the scientific background to understand these issues there should be more not less discussion in the media. Atmospheric effects of mans activities are poorly understood, so two main points of view are adopted - 'how can little old us effect something so big???' and 'don't piss in the bath'.
The greenhouse effect (the ability for certain atmospheric gases to trap more heat than others - leading to an overall warmer planet) is a scientific fact. Whether the effect is increasing or not is currently being debated - with the vast majority saying yes, it is.
The Mars results are interesting because they demonstrate that even without life, let alone industrial level life, the level of greenhouse gases in the atmosphere can change year on year.
What it does not, cannot, tell us is wether this is a cyclical or progressive change. Thats the same as here on earth. The earth is warmer now than it was 100 years ago.
I'm a 'don't piss in the bath' person myself.
Um, yeah, well....
Plants are great, but they don't generate new oxygen, they just recycle the old stuff. If you start with 10^100 moles of CO2 and 10^100 moles of H2O, that works out to, 2*10^100 moles of C, 2*10^100 moles of H and 3*10^100 moles of O (1.5*10^100 moles of O2), right? So, all you need to do is:
a) find a massive source of CO2 (in the gigaton range, to start with) that will give you something close to earth atmospheric pressure
b) find a massive source of water (in the petaton range, to start with) to help with the atmospherics and the temperature stabilization
c) increase a and b to account for losses due to soil mineralization of the O
d) find a lichen that will grow (and reproduce) on Mars
oh yeah,
e) find some way to stimulate some plate tectonics to recycle the minerals and crack the O off the Fe in the crust (this is a long term goal, though)
The man who does not read good books has no advantage over the man who cannot read them. - Mark Twain
It can't hurt to cut down on CO2 emission, even if it's not the 100% cause of global warming.
Yes it can. It can remove cheap energy and transportation sources for billions of people, maintaining or increasing rates of poverty and starvation around the globe.
But if it turns out that it was the influence of man, there won't be an 'undo' button!
Yes, there will. The "undo" button will be to reduce CO2 emissions after we've proven that they are a problem, and watch them fall back to equilibrium. We haven't passed some invisible "point of no return"; the Earth isn't currently the hottest it's been this millenium, much less the hottest ever.
I'm shocked that a NASA scientist would make such sweeping statements and predictions based on what the article portrays as a few photographs over on year of Mars history.
They don't seem to rule out that this ice is being shifted to another location. Perhaps the other pole? Could it be settling underground in solid form? Yes, they make some comments about ravines and such, but the comments are superficial.
As I think I saw another poster mention, could it be a part of some longer event cycle? Could some other chemistry be at work, with the CO combining with something else instead of transforming to a gas?
There are lots of questions that weren't answered about the WHY and WHERE. Not to mention that this throws more evididence at the global warming issue of Earth. If Mars is warming, perhaps the Earth warming is a part of some larger issue such as a warmer period in a solar cycle. Perhaps we are moving through a warmer part of the galaxy/universe and that's making everything hotter. Perhaps the higher gaseous CO2 levels on earth are due do higher temperatures on the planet, and not the other way around.
Article X: The powers not delegated... by the Constitution...are reserved...to the people
Yay! Another uninformed know-it-all!
There is no scientific debate about whether or not global warming (on earth) is occuring. We have global average temperatures for a 150 years. This data shows a clear warming trend over the last 12 years or so. No amount of wishful ignorance can make these numbers go away.
The debate is whether or not we are causing it. However, the ignorant often group them, which parallels the debate around evolution. People say that they don't "believe" evolution happens, when scientists have observed it happening. The scientific debate is over natural selection, and to what extent it is the main mechanism for evolution.
As long as people perpetuate inane talking-heads style opinion over scientific fact, our populus will remain ignorant. Which is to say, will always be the case.
Working toward a usable PDA environment in the spirit of Newton OS: Dynapad
I always thought that the gravity on Mars was low enought that the atmosphere just leaked away.
The escape velocity at the surface of Mars is only a little less than 1/2 of what it is at the surface of the earth. The thermal velocity of a particle scales with the square root of temperature. Hence a gas particle on Mars would only have to be a fourth as hot as it's Earth bound cousin in order to escape.
Now the particle has to not only be hot, but also have enough room to move that it can get away into space without hitting other gases and cooling off. This isn't really a problem since light molecules naturally drift to the higher levels, and in the case of Mars, it's pretty rarified air to begin with. Atmospheres (in the inner planets) drop off dramatically in the scale of hundreds or thousands of kilometers, whereas the planet is several 100,000s of kilometers in radius, so being high in the atmosphere only cuts a few percent off of escape velocity.
Now the real problem here is when you look at the numbers. On Earth, H2 and He won't escape at room temperature. In fact, they have to be heated to between 10 and 100 times room temperature (Kelvin Scale) in order to escape. We assume that cosmic rays, solar wind, and other atmospheric phenomena can give this much energy to an appreciable percentage of H2 and He so that non-neglible amounts bleed away into space. In any case it's not a very fast process at current.
N2 and O2, being 7 and 8 times the mass of He would have to be heated to 7 and 8 times as hot as He to escape. Given the historic composition of the atmosphere on Earth we can assume that this degree of heating is rare enough to have a pretty neglible impact on atmospheric composition.
However, if you have a considerable incidence of unshielded ionizing radiation then single atoms of N and O might be present in significant quanities and would need only 3.5 and 4 times the temperature of He's escape.
As I said, in the beggining, on Mars you can escape while being only 1/4 the escape temperature on Earth. So, yes, it is possible that ionizing radiation produces enough atomic N and O that an appreciable portion of it can escape into space. Temperatures may even be high enough to bleed of non-trivial quantities of N2 and O2 from Mars, but remember it's still a rare event since the temperatures needed are well about the surface temperature and little of the air will ever get hot enough. Could this alone account for the thin martian atmosphere? Probably not. More likely the dominant phenonema involves gases being absorbed into rocks and mineral deposits.
On one final note, thermal differentiation of atmospheric composition was probably most important early in the life of the solar system when the sun was significantly hotter. What is around today isn't likely to change much by virtue of bleeding gases into space.
This should be glaringly obvious, but the author clearly didn't want the facts to get in the way of a good story.
1) This happens every year anyway. The martian atmosphere gets thicker every year as a result of its less-than-circular orbit. Every year, there are times when Mars is closer to the sun than the rest of the year, which allows the planet to absorb more solar energy, melting more of the carbon dioxide in the ice caps and adding to the atmosphere. This might actually snowball if it weren't for the fact that there are other times of the year where the CO2 starts to freeze out, snowballing in the other direction.
2) While it might be exciting and all that in a million years, you *might* not need a spacesuit to walk on the surface of mars, more than likely it's just a statistical anomaly because it was slightly warmer this year than last. As if we never see that sort of thing on earth or anything. The author saves this little tidbit of information for last, because otherwise there's not much of a story here at all. (and of course, there really isn't.)
3) This is, if anything, simply proof that some years the sun is hotter than others, which might be a much easier explanation for an increase in the average surface temperature of the earth in recent years over the theory that the media likes to push that we're all to blame. The media likes this theory simply because scaring people is good for business. As in this article, it's not the actual facts that matter as much as an exciting story.
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