Climate Change due to Global Warming – a hoax?

[cbacba]

Originally Posted by nemesis9

Oh, so we can model Mar's climate so well, but when it comes to Earth's climate, we just dont know nothing? Mars would likely be much cooler than it is if not for the CO2. How can it get up to the nice balmy temperature of 20C on Mars?

It doesn't take a GCM to get a basic conservation of energy balance and if you simply do the math, you'll realize that the mean temperature for mars is neither balmy nor any different than a mean temperature would be if mars had no atmosphere or co2.

[nemesis9]

Originally Posted by cbacba

It doesn't take a GCM to get a basic conservation of energy balance and if you simply do the math, you'll realize that the mean temperature for mars is neither balmy nor any different than a mean temperature would be if mars had no atmosphere or co2.

That is simply not true, In fact, the Mars rover Spirit even found that the infrared absorption of carbon dioxide varies versus density (height) and used the data to calculate the temperature versus altitude on Mars. I don't know how you can keep denying that CO2 absorbs infrared, thus warming it's surroundings. It's common sense. If I have some factor(s) that warms a gas, then everything ambient to that gas will be warmed.

[nemesis9]

Originally Posted by nemesis9

That is simply not true, In fact, the Mars rover Spirit even found that the infrared absorption of carbon dioxide varies versus density (height) and used the data to calculate the temperature versus altitude on Mars. I don't know how you can keep denying that CO2 absorbs infrared, thus warming it's surroundings. It's common sense. If I have some factor(s) that warms a gas, then everything ambient to that gas will be warmed.

And furthermore, that infrared absorption of CO2 versus altitude data is part of a global climate model for Mars. How could one possibly attempt to characterize complex systems *without* models. Tell me that.

[cbacba]

Originally Posted by nemesis9

And furthermore, that infrared absorption of CO2 versus altitude data is part of a global climate model for Mars. How could one possibly attempt to characterize complex systems *without* models. Tell me that.

golly gee, you mean to say that absorption varies with how much matter (CO2) is present at an altitude? duh!

BTW, what is your ref. for the article. I did look around a bit but didn't find much. Was that the kludge experiment concocted after launch that points the spectrograph up in the sky rather than at the ground? It was pretty much just the usual lapse rate and also modulation due to amounts of dust absorbing energy in the atmosphere as well. It still looks like the mean surface T is right in the vacinity of what it would be were there to be no atmosphere, just from albedo and insolation at the TOA. WWWhat with all that dust absorption going on warming the planet, just how much warming has the CO2 contributed to the surface there?

sirius.bu.edu/aeronomy/withersmericarus2006.pdf

I guess I must've missed their GCM video game for mars. I didn't really noticed an iterative time based model needing to be invoked for that. Once upon a time a model meant a description of something, perhaps with some assumptions and perhaps accurately portraying measurable results. I guess we could distinguish between a model - such as the model of the sun, ie a density curve, a temperature curve, various assumptions about areas being radiative or convective yada yada yada - and distinguish between a GCM which is a time iterative attempt to figure out things without knowing what they are and without having full details or significant accuracy or resolution - sort of like maybe Laura Croft versus the god of mars in tomb raider XIV.

[jaygee340]

Good info nemesis.

[nemesis9]

Originally Posted by cbacba

golly gee, you mean to say that absorption varies with how much matter (CO2) is present at an altitude? duh!

So, you admit global warming due to CO2 is true. It's about time. Cbacba said, "Absorption varies with how much matter is present at an altitude." That is about as fine a layman's explanation of global climate change as I can think of. You did it, you have explained it. And that heat absorbed is warming it's surroundings, namely the planet earth, the land and the sea and the sky.
We pump CO2 into the atmosphere, like the burning of gasoline:

C8H18 + O2 --> H2O + CO2

See that CO2 on the right (output) side of the equation, that is "matter (CO2) present at an altitude" as you say. And those molecules near the glaciers will warm those glaciers, and those now-cooler CO2 molecules will absorb heat from CO2 layers a little further up, and so on and so forth.

Great to see you understand climate change now.

[nemesis9]

Originally Posted by cbacba

BTW, what is your ref. for the article. I did look around a bit but didn't find much.

You can read about it here.

NASA rover takes Mars' temperature - mars-rovers - 13 February 2004 - New Scientist Space

[Bored Wombat]

Originally Posted by cbacba

It doesn't take a GCM to get a basic conservation of energy balance and if you simply do the math, you'll realize that the mean temperature for mars is neither balmy nor any different than a mean temperature would be if mars had no atmosphere or co2.

Mars' greenhouse effect is about 5K to 10K.

Much less than earth's of about 30K.

[cbacba]

Originally Posted by nemesis9

So, you admit global warming due to CO2 is true. It's about time. Cbacba said, "Absorption varies with how much matter is present at an altitude." That is about as fine a layman's explanation of global climate change as I can think of. You did it, you have explained it. And that heat absorbed is warming it's surroundings, namely the planet earth, the land and the sea and the sky.
We pump CO2 into the atmosphere, like the burning of gasoline:

C8H18 + O2 --> H2O + CO2

See that CO2 on the right (output) side of the equation, that is "matter (CO2) present at an altitude" as you say. And those molecules near the glaciers will warm those glaciers, and those now-cooler CO2 molecules will absorb heat from CO2 layers a little further up, and so on and so forth.

Great to see you understand climate change now.

I've understood it since it appeared to be cooling off in a big way. What seems to be missing from your understanding is that increased absorption leads to increased emission (even at constant T).

[cbacba]

Originally Posted by Bored Wombat

Mars' greenhouse effect is about 5K to 10K.

Much less than earth's of about 30K.

Let's see, a calculation of mean temperature for an object at Mars' orbit with an albedo of about 12% is about 217 assuming no atmospheric absorption. Let's see, a recent textbook (Chaisson & McMillan) puts the average T for Mars at about 217 degrees. 217-217 = 5 to 10. Congrats on your new math wombat.

To clarify slightly, estimates for the mean T of mars range from 210 to 227 K. That places the atmospheric warming at between a cooling of 7 deg K and possibly a warming of up to 10K. Hence, the information available suggests that there is likely no warming occuring. Note that this is with 40 times the actual amount of co2 present in the atmospheric column of mars compareed to that of earth. This is equivalent to over 5 doublings over that of earth's approximately 10 doublings.

Considering that each doubling produces approximately an incremental value of around the same amount, one is stuck with the range for mars of a doubling producing anywhere from a -1/3 deg K up to possibly as much as just over +1/2 deg K, taking the 227K T which doesn't seem to be quite as popular as lower T values.

Comparing with earth, which does have higher atmospheric pressures that offer greater broadening from other sources, but not much self broadening or broadening by other co2 molecular pressure, your number of 30 K for a T increase can also be compared. The number 95% has been attributed to h2o and that is most likely quite valid when considering cloud effects. It's too high for just vapor. But then, around half of the earth's atmosphere contains clouds so a mean value of 30K rise due to our atmosphere would not be valid for clear sky only scenarios. Hence, I'm using 95% attributable to h2o, leaving 5% to others. That leaves 1.5 K available for other sources. If we assume co2 constitutes all of it (which is wrong) then for our 10 doublings worth of co2, we have the sum of 1.5K. Roughly being equal, that provides us with 0.15K rise per doubling.

Ignoring with line width variation, a 0.15k rise per doubling would offer about a 2.2k deg rise in mean martian temperature.

As a quick aside, the eccentricity of the mars orbit is significantly greater than that of earth's. A mean temperature measurement that doesn't take this into account could easily be off by a serious amount. Since mars spends more time further out, higher T values occur during less time than do lower and could explain the high reading 227k which is competing with 217 and even 210k measurements.

btw, none of this includes the dust factor warming. Atmospheric dust on mars can reach total coverage of the entire planet in massive dust storms.