The aerosols conundrum: Research shows that aerosols not only cool, but also heat the planet

Jul 09, 2010 by Morgan Bettex
Many climate researchers assume that aerosols — microscopic particles in the atmosphere — help to cool the Earth. But new research from MIT shows that aerosols not only cool but also heat the planet, a finding that calls into question some key assumptions about climate change. Image Credit: NASA

Just how much warmer Earth will become as a result of greenhouse-gas emissions — and how much it has warmed since preindustrial times — is much debated. In a 2007 report, the Intergovernmental Panel on Climate Change, an agency formed by the world’s largest governments to assess climate change, said that the planet’s average surface temperature will rise by between 2 and 11.5 degrees Fahrenheit by 2100, with a best estimate at between 3.2 to 7.2 degrees F. However, the IPCC’s computer models have a record of overestimating warming: If the IPCC models were right, the planet should now be hotter than it is.

The IPCC attributes the discrepancy to in the atmosphere that are created by both nature (dust blown by desert winds) and human activity (liquid droplets created from fuel combustion). Because aerosols help cloud droplets form into icy particles and reflect sunlight back into space, they help to cool Earth and possibly mitigate warming caused by emissions. But Richard Lindzen, the Alfred P. Sloan Professor of Meteorology in MIT’s Department of Earth, Atmospheric and Planetary Sciences, is among those who question the accuracy of the IPCC models, and he has been critical of the aerosols argument.

In a paper published last month in the Lindzen and his former postdoctoral researcher, Yong-Sang Choi, suggest that aerosols not only cool the Earth-atmosphere system — the system by which the atmosphere and oceans interact and affect the global climate — but also heat it. By describing the potential dual effects of aerosols, the research questions the IPCC’s models. 

“Current climate models generally overpredict current warming and assume that the excessive warming is cancelled by aerosols,” the researchers say in their paper. “[Our research] offers a potentially important example of where the secondary effect is to warm, thus reducing the ability of aerosols to compensate for excessive warming in current models.” That is, the degree to which aerosols can compensate for model over-prediction of warming remains open, the research suggests.

While Thomas Stocker, co-chair of the IPCC’s Working Group I that is examining the physical scientific aspects of the climate system and , declined to comment on the study, he says Lindzen and Choi’s research is part of relevant peer-reviewed work that the group will assess in its Fifth Assessment Report about climate change to be published in 2013.

Pinning down aerosols

In their research, Lindzen and Choi analyzed data about cloud formation and dust aerosols, or tiny particles of sand and silicate in the atmosphere, that were collected by NASA’s Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite from June 2006 through May 2007. Their analysis revealed that there were about 20 percent fewer “super-cooled” cloud particles — droplets that are a mixture of water and ice, but reflect more sunlight than ice — in regions that had dust aerosols. Such a difference, Lindzen and Choi suggest, could warm the atmosphere in those regions.

According to the researchers, the decrease in super-cooled particles occurs when aerosols travel to a layer of the atmosphere where the temperature is around minus 20 degrees Celsius, and they “effectively kill” super-cooled cloud droplets by causing them to form into ice. Fewer super-cooled cloud droplets would mean that clouds reflect less sunlight, which could have a warming effect on the climate. That effect, the researchers believe, needs to be incorporated into climate-change models. “The IPCC assumed that all the secondary effects of aerosols would be to increase reflectivity, so it has left out a very important factor that could lead to the opposite effect,” Lindzen says.

The work is important to the global-warming debate because it sheds light on the uncertainties of climate sensitivity, which is the term the IPCC uses to describe the change that a doubling of carbon dioxide would have on global average temperatures (the IPCC’s 2007 report estimates that change to be between 3.6 and 8.1 degrees F by the end of the century, with a best estimate of about 5.4 degrees F). According to Yale climate scientist Trude Storelvmo, “aerosol effects on climate, particularly via their influence on clouds, currently represent the most uncertain forcing of climate change.” Although the IPCC models assume that aerosols cool the Earth-atmosphere system, she cautions that “unless we can quantify this supposed aerosol cooling counteracting the warming due to increasing greenhouse gases, we cannot say what the climate sensitivity of the Earth-atmosphere system is.”

Because satellite data can be limited, she suggests that future research should include measurements of aerosol and cloud properties taken by instruments onboard aircraft that travel to the upper atmosphere. She thinks this combination could help address one question that remains unanswered in the paper: why few super-cooled clouds were detected over South America even though the satellite didn’t detect dust or carbon aerosols over that region.

Lindzen agrees that climate scientists can’t rely solely on remote sensing techniques to get “solid, incontrovertible data” about aerosols and clouds. Even so, he is eager for the launch of better satellites and instruments so that he and his colleagues can gather as much data as possible about how clouds evolve “so that we can better pin down what aerosols do.” Until scientists figure out that missing piece of the climate change puzzle, it will be difficult to predict the effects of future warming.

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Arkaleus
2.4 / 5 (16) Jul 09, 2010
This is wonderful news. With the guiding hand of our dear prophets in the IPCC, I can discover how I can be in poverty, but rich at the same time!

This conumdrum is washed away by the droning of the wind turbines I am made to power my home with. While my lights flicker on and off, I can meditate on the inner peace of knowing that while I may be made currency poor, my planet is turning as green as the food in my randomly-powered refrigerator.

I look forward to the day when I can look beyond my two-way telescreen and see Father Gore's great white mansion on capital hill, glittering with diamonds made of pure carbon. I am happy to serve mother earth and her self-elected priests! I know she needs lots of money, just like god used to before the woman got the house.

Sustainably yours,
Ark
GSwift7
2.4 / 5 (13) Jul 09, 2010
Don't worry Ark. The new owners of the country will set things back to rights. Once our friends in the People's Republic own a controlling interest of our country, I'm sure they will make a few changes in management. You'll have plenty of food in your roomtemperator once we become fully socialistic. One day we will share in the prosperity of our Eastern brothers and you will have everything they think you need.
GSwift7
1.9 / 5 (14) Jul 09, 2010
P.S. It's funny how the AGW people don't have much to say about this one. I was sure that one of them would write something about how MIT and Harvard are just a big bunch of deniers who know nothing about climate study, or gathering reliable data.
thermodynamics
5 / 5 (7) Jul 09, 2010
GSwift7: It is a relatively new article - so some of us who look at the physics of articles might not have had as much time to think about it as those who skim it and leave polemics. I don't see a single technical point in the first three comments here. So, let me make a technical point. In almost all of the literature on GW (including the IPCC reports) the effect of aerosols are recognized as poorly understood. They are central to understanding the water cycle as well as understanding direct radiative interaction as both black bodies and gray bodies. This paper adds to the understanding and is testable (which many hypotheses are not). I would very much like to see the measurements they suggest made so the models can be improved (as I think you agree they should be). I will be interested in the full paper and the interactions they show. The issue could also be applicable to volcanic aerosols (which are also poorly understood) and I hope to see someone apply this to them.
GSwift7
2.7 / 5 (9) Jul 09, 2010
Now that's a good comment Thermo. I agree 100%, as you knew I would, because you usually take the time to read other people's comments and reply thoughtfully (even when you don't agree with me, lol). It's Friday evening and I was just having fun with the concept of the refrigerator that only works part-time. It reminds me of a watch my first girlfriend bought me back in High School. It was supposed to be solar powered, but there was something wrong with the rechargable battery, so it stopped every time my sleeve covered it up. I had to wear it anyway or hurt her feelings, lol. If I was making a serious comment, it would mirror yours almost exactly. That's prety much what I always say regarding climate study and prediction though. I'm not sure they are right or wrong, but I'm relatively certain that many reports are less certain than they imply. It's refreshing to see one that talks about their own uncertainties while delivering the report.
GSwift7
2.4 / 5 (9) Jul 09, 2010
P.S. Thermo, you'll probably get negative comments from certain people who probably weren't aware of the aerosol problem. I've tried to mention it before and got called a denier who doesn't understand climate research. haha. Lots of people don't understand the problems with satelite temp data either. Even the latest ESA interferometer satelite constellation has limitations.
TegiriNenashi
1 / 5 (10) Jul 09, 2010
Aerosols are small particles. Being in quantum entangled state they exhibit cooling and warming effect at the same time.
thermodynamics
4.8 / 5 (6) Jul 09, 2010
GSwift7: I appreciate your serious comments. I am going to have to get used to your "sense of humor." :-) Sometimes it is not clear to me if you are trying to be funny or just not paying attention to the articles. It is good to know you are paying attention to the articles even if you are not agreeing with me (not that all do all the time).

Tegiri: WHAT? Are you serious? Aerosols are small particles, but huge in quantum terms. It is not possible for them to be entangled. Not only that but superposition of states and/or entanglement has nothing to do with cooling and warming. Either you are trying to make a joke or you need to get a very simple book on quantum mechanics.
Parsec
4.3 / 5 (4) Jul 09, 2010
Its quite unusual for climate change articles to get serious and thoughtful comments (of course Tegri always tickles my ignorant radar). I agree with the main thrust. Aerosols are poorly understood, and quite important. In addition, there are a lot of other types of uncertainties in the climate models.

Unfortunately, if one takes the recent dip in measured solar output from satellites associated with the current multi-year solar sunspot minimum, and map the expected cooling on top of the predicted warming, it closely matches measured temps. When the sun really starts the next cycle and goes out of minimum we can expect a very sharp increase in measured average global temperatures.
TegiriNenashi
1.3 / 5 (4) Jul 09, 2010
OK, I followed thermo_dy/dx advice and have read some introductory textbook. It appeared that I was wrong in the assertion that entanglement state is affected by particle size. It is interference with the environment that makes the state collapse. How about this: aerosols float freely high above in pristine stratosphere away from noise and pollution created by evil humans and, therefore, are entangled. Darn, I still have to demonstrate that cold and warm states are incompatible...
GSwift7
2 / 5 (5) Jul 09, 2010
lol Teg. That was good.

@Thermo: Don't worry about not recognizing my "humor". I get that from people all the time, so it MUST be me, not you. BTW, I did eventually go back and read your suggested reading regarding that CryoSat-2 article on ice thickness. Yes, you were right about the real info being avialable to anyone who is willing to spend enough time, and who has a MUCH better education than the average Joe Lunchbox. Take it easy on Tegiri, I can tell that he looks stuff up more often than most people would.

@Parsec: That will be a big test in my mind. If we do actually see the GW avalanche you're talking about, then we should get a lot better idea about what causes it. On the other hand, if we don't see the predictions come to fruition we're going to have an even better idea about what we need to study going forward. It's a win-win for researchers really, but I shudder to think about how the CO2 profiteers will exploit any temp increase.
thermodynamics
5 / 5 (3) Jul 09, 2010
GSwift7: I would expect to take some time to see how the sun interacts with the climate even though it is coming off a deep minimum. We are moving into a La Ninia and that should mitigate the solar effects for a while. However, the solar cycle is longer than the ENSO and we should see some oscillations to a combined solar max and an El Nino. If things are not warm in those years there is a problem with the modeling tools that will be very hard to explain.
GSwift7
1.8 / 5 (5) Jul 09, 2010
MAJOR NOD to you Thermo. That is very well said. Now that we have better mearsuring tools AND a better idea of what to measure, we're going to get an avalanche of new findings over the next couple decades, no matter what the climate is doing. I hope I'm right about claims being exagerated.
thermodynamics
5 / 5 (3) Jul 10, 2010
GSwift7: As we have discussed before, all measurements and estimations have uncertainties. I completely agree that we will get more and better data that helps to reduce the uncertainties. However, it is my opinion that, no matter what the science says, there will still be deniers and those who are hysterical about the earth bursting into flames. If you pay attention to the polls of scientific knowledge in the United States, there is very little hope that science will actually prevail. However, I hope to be here in these discussions as the science delivers the verdict (and to watch those with either strong opinion continue to rant).
SeymoreM_Athy
5 / 5 (1) Jul 10, 2010
I have a quick question, with all the radio waves, microwaves and all the other waves that we are putting out there into the atmosphere. Is it possible that this might have an effect on the global temperature. I'm wondering if i should turn off my cellphone or leave it on. Any answer would be greatly appreciated
thermodynamics
5 / 5 (4) Jul 10, 2010
Seymore: Great question with two answers.

1) radio and microwaves do not heat the atmosphere much and do not carry much power anyway.

2) Devices that can be turned off always should to reduce demand on the electric grid. That is energy conservation and includes things like instant-on TV sets where the remote can turn it on (that means it stays running waiting for the remote), or turning off your lights when you are not in the room.

Energy conservation is another topic that would take up a lot more than our allotted 1000 characters.

Keep the cell on without worrying about heating the atmosphere. However, there are concerns about the radio waves causing health problems.
GSwift7
2 / 5 (4) Jul 10, 2010
@Seymore:

The main ecological effect of our communications networks aren't from the broadcast waves, but from the power consumption of the ground stations. The environmental damage is mainly done where the electricity is produced, not where it's consumed in this case. In most cases in the US, that means coal. The computers that run the communication networks are kinda power-hungry beasts these days, especially when you include the air conditioning and such.
GSwift7
2 / 5 (4) Jul 10, 2010
Sorry Thermo, I didn't mean that I hope I'm right so that I can say "I told you so". I just mean that I hope the reality isn't as dire as some sources suggest, or we're all in deep trouble. Time will tell.

It's kinda like when a party you don't like holds the majority. You really may not like them, but for the good of everyone, you still have to hope that whatever they do works.
marjon
1.7 / 5 (6) Jul 10, 2010
I have a quick question, with all the radio waves, microwaves and all the other waves that we are putting out there into the atmosphere. Is it possible that this might have an effect on the global temperature. I'm wondering if i should turn off my cellphone or leave it on. Any answer would be greatly appreciated

Radio frequencies are chosen so there is minimal atm absorption to maximize transmission through the atm.
That is one reason I question CO2 impact as CO2 absorbs little energy because of its concentration and its narrow absorption bands.
PinkElephant
4 / 5 (4) Jul 10, 2010
@GSwift7,
I just mean that I hope the reality isn't as dire as some sources suggest, or we're all in deep trouble.
Hope isn't much of a strategy. Personally, that's my biggest problem with 'sceptics': /wise/ people hope for the best, but prepare for the worst.
marjon
2.3 / 5 (3) Jul 10, 2010
@GSwift7,
I just mean that I hope the reality isn't as dire as some sources suggest, or we're all in deep trouble.
Hope isn't much of a strategy. Personally, that's my biggest problem with 'sceptics': /wise/ people hope for the best, but prepare for the worst.

How you prepare? Engage in coercive means to reduce a dubious gas or promote technologies like nuclear to increase energy production enabling more technology achievements?
thermodynamics
5 / 5 (4) Jul 10, 2010
Marjon: You said: "That is one reason I question CO2 impact as CO2 absorbs little energy because of its concentration and its narrow absorption bands." Do you have any specific information to add credence to this statement? Let me explain the circumstance (this will take more than one 1000 character post). As I am sure you are well aware, dry air is approximately 78% N2, 21% O2 and 1% Ar. Please add those up - my answer is about 100% because if the rounding. The remainder is mostly CO2 (about 390 ppmV). Water vapor is variable which is why I termed this a "dry atmosphere." The key is that N2, O2, and Ar do not interact (in any meaningful way) with infrared (IR) radiation. That means that only the trace gases do. Without those trace gases the earth would be colder than it is. The amount of water vapor varies with location whereas CO2 is much less sensitive to location (obviously it will be higher at a power plant than in a meadow). Continued.
thermodynamics
5 / 5 (4) Jul 10, 2010
Continued response to Marjon's comment about not believing CO2 is important.

So, let me recap the last post: 99.6% of the dry atmosphere does not interact with IR due to quantum mechanical restrictions (the bending and rotation modes are not in the section of the IR that is important in the black body radiation from the earth).

Back to the atmosphere. Of the remaining dry gases the next one in line is neon (18 ppmv) and it is not optically active. Then helium (5 ppmv) and it is not optically active. Finally we get to methane at about 1.8 ppmv and it is optically active because it has quantum mechanical bending and rotation motions in the IR spectrum.

What that means that you can strip all of the gas away except for H2O and CO2 and you will still have most of the IR activity left. You say that CO2 is not important because it is so dilute but it is not when it comes to optical activity.

Now we need to talk about about CO2 and water vapor overlapping (continued)
marjon
2.3 / 5 (3) Jul 10, 2010
How much energy is absorbed by CO2 compared to water?
thermodynamics
5 / 5 (4) Jul 10, 2010
Response to Marjon's comment about H2O and CO2 overlapping and so CO2 is not important. First, let me know where you get that information please. I will explain where I get mine. For much of my heat transfer simulation (combustion research) I use a book called "Thermal Radiation Heat Transfer" (4th ed) by Siegel and Howell. It is dense reading so I will point you to the pertinent sections and I will also summarize. I would start with chapter 11 on "Fundamentals and material properties for radiative transfer in absorbing, emitting, and scattering media." I will then point you are Figure 11-23 on page 468 which gives specific corrections for "correction on total emittance for band overlap when both CO2 and water vapor are present." The summary is a mathematical relationship that takes in the presence of both H2O and CO2. (continued in the next post)
thermodynamics
5 / 5 (4) Jul 10, 2010
Continued response to post on overlap of CO2 and H2O IR bands. The reason that engineers do not assume that if you have a band that covers H2O you shouldn't have to worry about a CO2 band within that range is that these are really not bands. Instead they are dense lines (with broadening due to things like molecular impacts, Doppler effect, Stark broadening, etc.). However, those lines do not necessarily fall on top of each other even though they are treated as bands. The reason for treating them as bands is that it makes the calculations easier. Considering there are tens of thousands of lines within each band it becomes very computer intensive to use them all so we use bands and then have a correction for the overlap. The overlap is not a trivial calculation. However, there are a lot who have only looked at the bands and their overlap and assumed that means there is no contribution from both when they overlap. That is fundamentally wrong. Both are important.
thermodynamics
5 / 5 (5) Jul 10, 2010
Final post on the comment that CO2 might not be an important contributing gas by Marjon. The comment you made is important and wrong. It was put forward by people who do not understand the quantum mechanical working of absorbing gases and the fact that most of the atmosphere has negligible (orders of magnitude less) impact in IR interaction than H2O, CO2, and CH4. Also, the idea that they negate through interaction is a simplistic view that is wrong. There is some overlap and it is important to recognize it and calculate for it, but it is totally wrong to assume it negates the contribution of one molecule. I hope this clears up this subject. This is physics in its most simple form. It is not a subject to debate. It does not even address any questions about AGW. It simply means that CO2 is an important gas and cannot be dismissed because it is a minor component of the atmosphere nor because it overlaps with H2O. Please do the math.
marjon
2.3 / 5 (3) Jul 11, 2010
If what you claim is true, an experiment can be set up in a pressure chamber where CO2 can be controlled as can H2O along with controlling and measure heat flow.
Who has done that experiment to validate such theories?
I looked at p.468, 5% change in emissivity (at what wavelength?) at 400K. (Water at 400K is called steam.)
Why do you use a reference discussing steam boilers?
marjon
1 / 5 (2) Jul 11, 2010
Yes, do the math. Integrate the energy under solar transmission curve at the surface, at the top of the atm and also integrate the earth emission curve.
How much energy is absorbed by CO2?
thermodynamics
5 / 5 (4) Jul 11, 2010
How much energy is absorbed by CO2 compared to water?


Great question. I think you probably already know the answer. H2O contributes apprximately 3x the amount as CO2. A reasonable summary is found on Wikipedia at:

http://en.wikiped...e_effect

I have not checked their work but it is the range of what I have seen in other places.
thermodynamics
5 / 5 (4) Jul 11, 2010
If what you claim is true, an experiment can be set up in a pressure chamber where CO2 can be controlled as can H2O along with controlling and measure heat flow.
Who has done that experiment to validate such theories?
I looked at p.468, 5% change in emissivity (at what wavelength?) at 400K. (Water at 400K is called steam.)
Why do you use a reference discussing steam boilers?


Are you kidding? Who has done these experiments? They are done in virtually every engineering radiative heat transfer lab in the country. Specifically, the labs of Modest are the most well known. As for the 400K temperature, if you look at the theory instead of not looking carefully, it does not matter if the H2O is above or below the boiling point since it is in vapor form. A simple look at the A and B sections of the figure shows it is slowly changing. Boiling point is a factor of atmospheric pressure. If you still think the temperature matters you can convert as given in the other tables.
thermodynamics
5 / 5 (4) Jul 11, 2010
Yes, do the math. Integrate the energy under solar transmission curve at the surface, at the top of the atm and also integrate the earth emission curve.
How much energy is absorbed by CO2?


Marjon: Are you just trying to keep me busy? Please go look up the energy balances for the earth that pop up on Google when you ask. I have explained how the physics works. I have answered your question on proportion. Do you just want me to keep answering questions you can easily look up? If you disagree with the physics, just say so. You can discover an new approach that negates quantum mechanics and become famous. I will stick with what I know and what I can find in the books and literature. You can invent a new physics.
marjon
2 / 5 (4) Jul 11, 2010
"Similarly, large differences among model projections of temperature, water vapor, and cloud distributions imply, for each model, different predicted changes in absolute, spectrally resolved radiation. The spectrum of IR radiance, if observed accurately and over the full thermal band, carries decisive diagnostic signatures in frequency, spatial distribution and time"
http://clarreo.la...rvey.pdf
If what Thermo claims is true, NASA is wasting a lot of money.
marjon
2 / 5 (4) Jul 11, 2010
Atmospheric absorption spectra: http://www.junksc...bspec.gif]http://www.junksc...spec.gif[/url]
Solar and earth radiance: http://www.junksc...bspec.gi
What is interesting about this chart ( http://www.junksc...-X4.png) is that contribution of CO2 reaches a limit, and that there is significant uncertainties among the three data sets. The only physics these three can agree upon is that a limit does exist to any CO2 'forcing'.
thermodynamics
5 / 5 (5) Jul 11, 2010
Marjon: Let me go over this one more time. As I explained (at some length) this is to point out that both H2O and CO2 are important gases. I did not try to write a book (although it feels like I had to). Did I say anything about clouds? Did I say anything about aerosols? Did I not say: "It does not even address any questions about AGW. It simply means that CO2 is an important gas and cannot be dismissed because it is a minor component of the atmosphere nor because it overlaps with H2O." If you cannot understand the difference between physics and an atmospheric model I can't help you. If you disagree with the physics, please just say so. Don't bring up climate after I specifically said I was not addressing that. Do you agree with the physics or do you want to invent your own?
thermodynamics
5 / 5 (2) Jul 11, 2010
Marjon: Great job. I use the most accepted reference for radiative heat transfer (except maybe Modest) and you bring up the JunkScience site. Let's just drop it. If you do not believe the physics and depend on sites like this, there is no reason to continue the discussion. We can let the readers take what they can from the discussion and make their own decisions.
marjon
2 / 5 (4) Jul 11, 2010
It is because I understand physics that I question CO2 contribution. The references from Junk science can be fount in literature. They just provide a convenient link.
You have not addressed CO2's contribution to solar energy absorption in the atm. Overlay CO2 absorption with solar and earth'r radiance and the energy is not significant compared to H2O.
marjon
1 / 5 (3) Jul 11, 2010
They are done in virtually every engineering radiative heat transfer lab in the country. Specifically, the labs of Modest

I have searched for data that demonstrates CO2 forcing and cannot find anything. If it existed, it would be trumpeted by AGWites, but instead, it really is a 'fudge factor' to make the climate models work.
thermodynamics
5 / 5 (3) Jul 11, 2010
Marjon: OK, you baited me out one more time. You said: "You have not addressed CO2's contribution to solar energy absorption in the atm. Overlay CO2 absorption with solar and earth'r radiance and the energy is not significant compared to H2O." I have to point out to you that no one says that either CO2 or water vapor absorb solar energy. Instead, they absorb the IR emitted by the earth. If you are missing the science so badly you do not understand that then there is not much I can do to help educate you.

As for experiments in IR absorbtance they start with Arrhenius in the late 1800s (measuring the IR from the moon) and were refined by Angstrom in the early 1900s. There have been continuous experiments since then. I am astonished you have not looked closely to understand that and still claim that measurements have not been made. Please note again, I have said nothing about AGW, only the physics and now you are using derogatory remarks like "AGWites." Physics please.
thermodynamics
5 / 5 (4) Jul 11, 2010
I really hate the 1000 character limit. Continued reply to Marjon's comment on the absorption of solar energy by the atmosphere. Both the sun and the earth act as black bodies. The difference is that they are at very different temperatures. The sun's temperature can be represented as 5,778 K and the earth as about 288K. What that means is that sun radiates most of its energy in the UV-VIS-NIR (Wien peak around 502 nm) while the earth radiates most of its energy in the IR range with a peak around 1000 nm. The water vapor and CO2 will absorb energy from any source - but the majority of the energy coming from the sun is not in the range where H2O and CO2 will absorb much. On the other hand, both CO2 and H2O are strong absorbers in all of the areas the Earth emits in. Hence the selective absorption of the preponderance of energy from the earth and virtually none of the energy from the sun. To think that absorption of solar energy is the greenhouse effect is wrong.
marjon
2.3 / 5 (3) Jul 11, 2010
This paper suggests that emissivity of CO2 and H2O have temperature dependence.
http://journals.a...2.0.CO;2
So your references to water at 400K doesn't appear to apply in the atmosphere that ranges from 200K to 300K.
My references in the JunkScience website show what you just wasted words on thermo.
The question still remains, how much energy is absorbed by CO2 and what is the capacity for CO2 to absorb energy?
Both the sun and the earth act as black bodies.
No they do not. They do not even act as gray bodies.
marjon
1 / 5 (2) Jul 11, 2010
Thermo, if you are trying to sell the idea that 400ppm can create significant climate change, then how can you assume the sun and earth act as blackbodies or even gray bodies? That is a major simplification.
thermodynamics
5 / 5 (1) Jul 11, 2010
Marjon: First let me agree that the sun and the earth act slightly differently from black bodies but they are also not gray bodies. I had hoped to stay a little out of the trenches. Apparently not. Many people refer to the earth and sun as black bodies (emitting all energy possible at a given temperature and following a specific shape of a curve) or gray bodies (energy at every wavelength is diminished by a specific fraction). However, the reality is that both are selective emitters with bands carved out of the spectra. In reality we do approximate them as gray bodies as Marjon noted but the reality is that the reason you need a computer is that they are really selective emitters and the bands and wavelengths need to be accounted for. This side bar does nothing to further the argument but is the correct way of addressing the situation. Thanks for pointing it out Marjon.
thermodynamics
5 / 5 (1) Jul 11, 2010
Correction for a typo in one of my earlier posts (of the myriad of posts on this subject). I said: "the earth radiates most of its energy in the IR range with a peak around 1000 nm." I actually missed a zero. The earth Wien maximum is around 10,000 nm. I'm surprised Marjon didn't catch this one. :-)
GSwift7
1 / 5 (1) Jul 11, 2010
Okay, so on the high side, CO2 accounts for 26% of retained heat. It also seems fair to say that anywhere from 1/4 to 1/3 of CO2 is human-made. Using the high side of that, and rounding up, that lays about 8% of the greenhouse effect at our feet because of CO2. The signifigance of the above article is that if aerosol is a significant part of the warming, then you have to reduce the share that CO2 holds. If you use low side estimates, then it's way less already. 9% for CO2, 1/4 of which is human-made, gives us 2.3% of warming caused by human CO2. So, we're talking about anywhere from 3% to 8% of a 1 degree increase in temperature. So, if you cut the world CO2 emissions by 20% (a lofty goal), you would see a difference of .6% to 1.6% in the net effect of human CO2 on global temperatur increase. I know you're going to try throwing all kinds of complicated extra factors into it, but it is still going to be a small quantity. If Aerosol is involved, then it gets even smaller.
GSwift7
1 / 5 (1) Jul 11, 2010
I'm going to go way out on a limb here and propose that 3 to 8 percent of a tenth of a degree global temperature increase per year is exceedingly difficult to measure accurately and in fact falls below the threshold of statistical signifigance compared to the accuracy of data collection methods. Hence, man-made CO2 is not measurably significant in this context.
marjon
2.3 / 5 (3) Jul 11, 2010
Correction for a typo in one of my earlier posts (of the myriad of posts on this subject). I said: "the earth radiates most of its energy in the IR range with a peak around 1000 nm." I actually missed a zero. The earth Wien maximum is around 10,000 nm. I'm surprised Marjon didn't catch this one. :-)

Most in the IR business use microns. 300K => ~10um with emmissivity of 1.

so on the high side, CO2 accounts for 26% of retained heat.
Who says? 400ppm accounts for 26% of retained energy?
It also seems fair to say that anywhere from 1/4 to 1/3 of CO2 is human-made.

Why is that fair to say?
marjon
1 / 5 (2) Jul 11, 2010
It also seems fair to say that anywhere from 1/4 to 1/3 of CO2 is human-made.

"Anthropogenic (man-made) CO2 additions comprise (11,880 / 370,484) or 3.207%"
http://www.geocra...ata.html
GSwift7
1 / 5 (1) Jul 11, 2010
I know marjon. I am not agreeing with 26%, I was just using Thermo's worst case scenario. It came from this page: http://en.wikiped...e_effect
They state a range of 9-26% for all carbon in the atmosphere, not just mmanmade. I then compared CO2 levels beore and after the industrial revolution to estimate that between 1/3 and 1/4 of that CO2 is manmade (maybe even less really). That gave me a range, from one extreme to the other of 2.25% to 8.58%. Those percentages represet my rough estimate of total absorption of manmade CO2. Your number falls well within that range. I was just pointing out that if the total anual temp increase is 1/10 of a degree, then the portion caused by manmade CO2 is very small indeed. 3.207% of 1/10th of a degree is impossible to measure in terms of global annual temp. Even an extremely small error bound moves you beyond the extent of the effect you are trying to measure.
GSwift7
1 / 5 (1) Jul 11, 2010
by the way Thermmo, we don't live on a dry planet, so using analogies involving a ficticious water-free world aren't very helpful. You can't just disregard the lion's share of greenhouse gass. Sure, CO2 is huge if you ignore water, but that's like saying that the ocean is mostly made of living things, if you ignore the water.
GSwift7
1 / 5 (2) Jul 11, 2010
"To determine the total radiative forcing of the greenhouse gases, we have used IPCC [IPCC 2001] recommended expressions to convert greenhouse gas changes, relative to 1750, to instantaneous radiative forcing (see Table 1). These empirical expressions used for radiative forcing are derived from atmospheric radiative transfer models and generally have an uncertainty of about 10%. "

That's from the NOAA web site. They are the source for most forcing estimates.

"The estimated uncertainty in the Mauna Loa annual mean growth rate is 0.11 ppm/yr. "

That's the uncertainty of annual CO2 concentration growth rate since samples first where taken. The annual growth rate is 1.44% on average, so that's another error of nearly 10%.

The few places where I could find NASA/GISS error estimates, they show a +.2/-.2 degree uncertainty in temperature estimates.

News flash people: That's just the tip of the iceberg of uncertainty. I could probably keep listing uncertainties for a long time.
GSwift7
1 / 5 (2) Jul 11, 2010
Just to set the score straight. That NASA uncertainty is 20% of the 1 degree temp increase observed. So, when you talk about how CO2 is causing climate change, make sure you ignore the water vapor as NOAA did in ALL of their studies, and make sure you ignore repeated uncertainties of 10-20% in much of the sited references of the IPCC.

AS long as we're pretending that there isn't any such thing as water vapor, let's also pretend that there's no such thing as CO2.
thermodynamics
5 / 5 (2) Jul 12, 2010
GSwift7: I hope you understand that no one has ignored water vapor. It is usually kept out of the estimates of the atmospheric composition because it is constantly varying. However, it is included in every model and also included in my discussion above. To say it is ignored is not correct (as I am sure you are aware). I said I would ease out of the conversation but when you make this blatant of an error I have to jump back in. Again, water vapor is never ignored when counting forcing, just when defining the DRY atmosphere. It is always included in the computations and is allowed to vary.
GSwift7
1 / 5 (1) Jul 12, 2010
The best estimate of HadCRUT3 error bounds are a tiny fraction better than the +.2/-.2 degree estimate of the error bounds of the NASA/GISS temp data.
GSwift7
1 / 5 (2) Jul 12, 2010
I know the serious science doesn't ignore water. However, most people don't understand the difference between a graph that shows the effect of CO2 without water and the reality of what happens. My problem isn't with the actual credibility of the real work being done, but with the misrepresetation of that work by people with an agenda. That isn't a trivial thing in climate change politics. I think a web site like this should do a better job of screening the nonsense, but oh well.
GSwift7
1 / 5 (1) Jul 12, 2010
P.S. Thanks for your patient responses.

So, do you really think CO2 has a signifigant role in the big picture, or not? You never really said what your conclusion is when you don't exclude H2O. If CO2 is worth mentioning, then what is your estimate of it's effect proportional to the net 1 degree temp increase? I notice that you've been careful not to make any claims as such so far. Do you even think it's possible to make an educated estimate of the impact of man-made carbon?
GSwift7
1 / 5 (2) Jul 12, 2010
P.P.S. The NOAA site that claims to be the authority in regard to forcing clearly states that they exclude H2O in all their figures. So, it's not entirely accurate when you said "Again, water vapor is never ignored when counting forcing". In reality, the IPCC reports exclude water vapor in regard to forcing because they are based on the NOAA reports which completely exclude water, according to NOAA. I looked it up. :)
GSwift7
1 / 5 (2) Jul 12, 2010
By the way, why would you exclude water vapor when talking about the greenhouse effect? I know it's variable, but so is temperature. There are many unpredictable and hard to measure variables, but why would you exclude the most meaningful variable? If the most signifigant variable varries so much that it makes the error bounds get out of whack, then doesn't that destroy other less signifigant factors in terms of reliability? You can't just ignore the most important factor because it make it difficult for you to support your opinion. I know you have an opinion based on the facts that you haven't shared here yet, and I wonder what that is.
GSwift7
1 / 5 (2) Jul 12, 2010
One last question: Why are there climate change politics?
GSwift7
1 / 5 (2) Jul 12, 2010
I would aslo like to know why you say " I said I would ease out of the conversation but when you make this blatant of an error I have to jump back in. Again, water vapor is never ignored when counting forcing,"

I don't see an error in what I said. I looked everything up from official sites. I did not use junk-science or whaterver. I used the root sources and spent hours reading PDF files from them. NOAA says that thier figures have deliberately removed the effect of water. They clearly state that in more than one place. NOAA is clearly stated as being the main source of forcing data in several places, including the IPCC. I hardly call that a blatant error on my part. They DO exclude water in many, if not most (or all) of the official reports in this context.

There's a HUGE disconnect between the science and the political reporting used to make policy and write news articles. Most people believe the political reports and the news stories
Caliban
3 / 5 (2) Jul 12, 2010
One last question: Why are there climate change politics?


Easy answer to that: mainly, if not entirely, because of people like mangy marjon, and now apparently, you- that, even after having been authoritatively refuted, through consistent and superior argument of the facts, continue to rise again, like boils, every time any article or comment is made that references global warming, with the same tired-ass talking points, pseudoscience, non science, and science fiction cited as proof in support of your active and evergreen agenda-driven denial.

The exact same thing holds true in Academic and Professional circles- and therefore political ones.

If you don't understand this simple correlation, you can hardly expect to be able to understand anything as complexly interacting as climate change.
GSwift7
1 / 5 (1) Jul 12, 2010
Caliban, did you even pick up a calculator or open an excel sheet here? Did you look at any of the referenced official sources? If you think I'm using psudoscience, then you're really knocking NASA, Hadly, NOAA, and IPCC, because that's where I got my info. It's all there for you to see, if you want. Show me a clear reference of where you think I said anything from those sites that isn't clearly true and I'll be happy to illuminate my points.

At least take the trouble to read my posts before you rate them low. lol. If you don't understant the complexities of climate change, then read more and feel less.
GSwift7
1 / 5 (2) Jul 12, 2010
Actually Caliban, the question about "why are there climate change politics?" is a little deeper than that. The answer lies in the fact that there is money involved. The money is big; big enough to attract heads of state from multiple countries. If you think that those people will tell the truth when billions of dollars are at stake, then you are dillusional. You really need to dig into the meat of the matter and decide for yourself whether they are telling you the truth or telling you the truth that makes them the most money. Do you really trust polliticians? Hmmm?
Caliban
5 / 5 (1) Jul 12, 2010
Actually Caliban, the question about "why are there climate change politics?" is a little deeper than that. The answer lies in the fact that there is money involved. The money is big; big enough to attract heads of state from multiple countries. If you think that those people will tell the truth when billions of dollars are at stake, then you are dillusional. You really need to dig into the meat of the matter and decide for yourself whether they are telling you the truth or telling you the truth that makes them the most money. Do you really trust polliticians? Hmmm?


If you bothered to read more and feel less, you would see that I already supplied you with that conclusion -Hmmm?

In regards to your previous post, I've already seen you and a number of other visitors here claim- against all reason- that the data that supports GW is somehow- miraculously- just the opposite.

I don't come here to watch Fox News, so don't expect to find a buyer for your "spintronics" here.
thermodynamics
5 / 5 (2) Jul 12, 2010
GSwift7: One more before I turn in. You keep saying that NASA, NOAA, Hadly, and the rest ignore H2O. Nothing can be further from the truth. Let me try to make this clearer than I, apparently, did before. Water vapor varies LOCALLY. Because of the large local variations it would be nonsense to lump it into the constituents of the atmosphere - so people talk about the DRY atmosphere (to avoid errors) and then locally they discuss humidity. When models run they run psychrometric sub-routines that determine the water vapor content at the resolution of their grid. The water vapor content can change from node to node in the models. NO ONE LEAVES H2O OUT. Every model includes it. I don't know how to make it clearer than that. Local versus global and the energy that goes along with phase change (we can discuss the phase change part more some other day if I you are not clear on it). Water can condense and evaporate. None of the other atmospheric constituents can.
GSwift7
1 / 5 (1) Jul 12, 2010
Okay Thermo, so what is the % effect of manmade CO2 on total warming, including water? Caliban, you're free to give an answer too, if you like.

Part b to that question would be: what do you think the effect of CO2 legislation will be on warming, including water.
Caliban
not rated yet Jul 12, 2010
@thermo,

No point in wasting your time- I've already, within the last few days, already been on the exact same merry-go-round ride with "GSwift7"(who bears a suspicious resemblance to the dachyparvile/Skepticus Rex sockpuppet of recent memory), with respect to the exact same issues, with the exact same result of obdurate refusal to concede that the same set of data cannot be made to support the opposite conclusion simply by saying that they do.

It's the same old argument by recursion trick, and it's all about the last word.

thermodynamics
5 / 5 (1) Jul 12, 2010
Caliban: Probably good advice, but I will still try to answer GSwift7 one more time. First I want to be clear that water vapor has a unique location among the things found in the atmosphere in that it can vary from point to point and can be in all three forms (liquid, vapor, and solid). As for the % effect of CO2, I have to leave that to the modelers. There is no simple way to answer that question without building a model and that would take the rest of my lifetime. So, I will kick back and see how the models refine over time and take their answers as approximations with uncertainties. I expect the various models to give us better results as they take the various phases of water and the energy transported by it into less uncertain account. Now let me explain what I mean by uncertainty. Nothing you or I estimate in the physical world is generally certain. So we put error bars on it and try to improve the estimates. That is science and asking for perfection is not science.
GSwift7
1 / 5 (2) Jul 12, 2010
"NO ONE LEAVES H2O OUT"

Here's a link to the NOAA web site, a well-referenced source of data: http://www.esrl.n...md/aggi/

take note of this statement in the first paragraph: "climate projections have model uncertainties which overwhelm the uncertainties in greenhouse gas measurements"

from the second paragraph: "The perturbation to radiative climate forcing which has the largest magnitude and the least scientific uncertainty is the forcing related to changes in long-lived and well mixed greenhouse gases"

Note: no water vapor.

From the 4th paragraph: "Nevertheless, the language of scientists often eludes policy makers, educators, and the general public. This index is designed to help bridge that gap."

NO mention of water vapor, and water is CERTAINLY NOT included in this estimate.

There are many other examples on this web site.
GSwift7
1 / 5 (1) Jul 12, 2010
OH my. That was a nice way to keep away from a problem with your arguments. Call me names, refute my intelligence and fail to answer the question, when you have had no trouble giving percentages in the past. I'm only asking for you to quantiify the base premise of your arguement that CO2 is causing global warming. Don't you have any source that gives a percentage with water vapor and everything else included? I can't find one, so I'm guessing nobody wants to talk about that. Can you disuade me from that opinion with some show of fact or theory?
GSwift7
1 / 5 (1) Jul 12, 2010
Thermo, it would be nice if you could just try to answer me once. When you say "one more time" you make it sound like you've given some reference to the % of climate change caused by manmade CO2, with all other factors included, which you haven't.

refute my points, don't call me names and ignore my assertions. I didn't make any of this stuff up. I'm reading the published work of experts. My info comes from the most accepted sources.
GSwift7
1 / 5 (2) Jul 12, 2010
demonstration after demonstration, of every model out there has shown verifiable proof of wild innaccuracy. They continue to improve the models and they remain innaccurate to the point that they lack predictive ability within measurable bounds.

You're using the calendar based on the earth-centric solar system if you're trusting the current climate models. I'll even venture that Plato's model of the solar system was more predictive than current climate models. You can check that out, but I'm sure I'm right. The current models are vastly wrong in fundamental ways and the data given out is misleading. Look at the NOAA site I referenced. If you were " policy makers, educators, and the general public" reading that page, would you know that water is excluded from this data?
thermodynamics
3.7 / 5 (3) Jul 12, 2010
GSwift7: Did you read the name of the page you sent out for the "evidence" that water vapor is not included? It is: "THE NOAA ANNUAL GREENHOUSE GAS INDEX (AGGI)." It is their "index" of the population of GHGs in the atmosphere. For exactly the reasons I gave above they leave water vapor out because it is local and multiphased. So, to inventory the other gases they leave out water vapor. The models keep it in. They say: "Because we seek an index that is accurate, only the direct forcing has been included. Model-dependent feedbacks, for example, due to water vapor and ozone depletion, are not included." Why would they mention model dependent if it was not in the models? I will say it again: "NO ONE LEAVES OUT WATER VAPOR." Also, where do you think I have called you a name in this dialog? I thought I had been pretty careful but I must have been careless somewhere. Please show me where so I can apologize. Name calling is not my style so please point it out.
marjon
1 / 5 (1) Jul 12, 2010
It seems like a very straightforward calculation to determine how much energy is absorbed by CO2. The absorption spectra are well known.
Is the challenge to determine how much of that energy is transferred to the environment?
thermodynamics
5 / 5 (1) Jul 12, 2010
It seems like a very straightforward calculation to determine how much energy is absorbed by CO2. The absorption spectra are well known.
Is the challenge to determine how much of that energy is transferred to the environment?

Marjon: All of the IR active species including water vapor interact (as I explained in the sections above on H2O/CO2 interactions). On top of that, the uncertainties in clouds and aerosols make the calculations computationally intensive and the boundary conditions difficult to specify. To make a simple estimate is a mistake and I see it too many times. It is simple to make a calculation based on a fictitious atmosphere but much more difficult to try to assess the impact in the real world. That is the reason I watch the models and see how they converge. Any simplistic approach is wrong. I went into some of the reasons in great detail above.
marjon
1 / 5 (2) Jul 12, 2010
How do they interact? A molecule of CO2 is floating around with a hundreds more H2O molecules. A photon excites a CO2 molecule which emits a photon of a different energy that may or may not be absorbed by a molecule of H2O.
Of course if you have CO2 gas at high temperatures, like >400K, self emission occurs.
Jigga
1 / 5 (1) Jul 12, 2010
Aerosols are making atmosphere dry, because they're serving as a redundant condensation nuclei here. The water cannot be lifted to the higher altitude in form of vapor, it just condenses in the form of smog and evaporates here again.

http://www.meteor...drought/

http://blog.clean...ortages/
thermodynamics
5 / 5 (1) Jul 12, 2010
How do they interact? A molecule of CO2 is floating around with a hundreds more H2O molecules. A photon excites a CO2 molecule which emits a photon of a different energy that may or may not be absorbed by a molecule of H2O.
Of course if you have CO2 gas at high temperatures, like >400K, self emission occurs.

Marjon: You cannot think in terms of a single photon. You have to look at an ensemble of photons of different wavelengths moving through the gas. The statistical distributions of the interactions is what is important. The emissions are not dependent on the gas being over 400K. It is a quantum mechanical transition. Naturally, there will be different distributions of excitations at various temperatures, but a floor temperature is not applicable. This is covered in an introductory course in statistical physics (but not at a first physics course level). You cannot simplify this.
marjon
1 / 5 (2) Jul 12, 2010
It is a quantum mechanical transition.
Which only occur with the interactions of photons and molecular electrons at various energies.

thermodynamics
5 / 5 (1) Jul 12, 2010
It is a quantum mechanical transition.
Which only occur with the interactions of photons and molecular electrons at various energies.


I don't see your point. Are you trying to imply that a photon cannot interact with a molecule at anything other than a specific temperature? Lines will move and broaden due to a number of effects including temperature but a photon can kick a molecule near absolute zero temperature.
marjon
1 / 5 (2) Jul 12, 2010
It is a quantum mechanical transition.
Which only occur with the interactions of photons and molecular electrons at various energies.


I don't see your point. Are you trying to imply that a photon cannot interact with a molecule at anything other than a specific temperature? Lines will move and broaden due to a number of effects including temperature but a photon can kick a molecule near absolute zero temperature.

Photons can only be absorbed or emitted at specific energies (wavelengths). CO2 can only absorb photons of specific energies (wavelengths).
thermodynamics
5 / 5 (1) Jul 12, 2010
Marjon: You said: "Photons can only be absorbed or emitted at specific energies (wavelengths). CO2 can only absorb photons of specific energies (wavelengths)." which is true. Do you understand why CO2 and H2O absorb in the IR? If not, do you need me to explain how the absorption works and why it is specific wavelengths that are absorbed? I am really trying to understand if you have a question or are just making a statement. If you are making a statement, please let me know what it is. If you are asking a question, let me know what that is so I can answer it.
marjon
1 / 5 (2) Jul 12, 2010
Do you understand why CO2 and H2O absorb in the IR?

Yes, I do.
thermodynamics
5 / 5 (1) Jul 12, 2010
Marjon: If you understand why and how CO2 and H2O absorb IR then what is your question?
marjon
1 / 5 (2) Jul 13, 2010
Marjon: If you understand why and how CO2 and H2O absorb IR then what is your question?

How much energy is absorbed by CO2 in the atm? It is a finite amount and a small amount based upon the CO2 concentration and the finite, narrow spectral bands.
Since the solar flux varies a bit, but not much, the total number of CO2 photons absorbable is fixed. As the other chart I referenced shows, there is a finite amout of energy that CO2 can absorb.
So why kill an economy for so little effect?
thermodynamics
5 / 5 (2) Jul 13, 2010
Marjon: Best estimates put the number at about 3.7±0.4 W/m2 for doubling of CO2 from pre-industrial times. Since I don't have my own model I take the consensus of models as a good reference. The thing I am sure you understand, that is very important is that the earth's atmosphere was slowly changing prior to us burning fossil fuels. It is now more rapidly changing due to our contribution (take a look at the logs of atmospheric and oceanic change in CO2). That change has a forcing effect that is estimated as I noted above. It is over and above the natural variation.
marjon
2.3 / 5 (3) Jul 13, 2010
Marjon: Best estimates put the number at about 3.7�0.4 W/m2 for doubling of CO2 from pre-industrial times. Since I don't have my own model I take the consensus of models as a good reference. The thing I am sure you understand, that is very important is that the earth's atmosphere was slowly changing prior to us burning fossil fuels. It is now more rapidly changing due to our contribution (take a look at the logs of atmospheric and oceanic change in CO2). That change has a forcing effect that is estimated as I noted above. It is over and above the natural variation.

How is that 'forcing' effect calculated? By tweaking the computer model to match observation. You asserted such forcings were measured in a lab. Where is the data?
thermodynamics
not rated yet Jul 13, 2010
Marjon: I have spent a lot of time answering your questions. I suggest you go make your own calculation and report it in a peer reviewed journal. I have written thousands of words above to try to answer your questions and you come back with some assertion that models are "tweaked." OF COURSE THEY ARE. All but the simplest fundamental "toy" models are tweaked by observation. No model falls off the shelf and is correct. All models have uncertainty. Go dig up the data yourself. I think you have the basis for a good paper and I don't want to write one here.
marjon
1 / 5 (2) Jul 13, 2010
Marjon: I have spent a lot of time answering your questions. I suggest you go make your own calculation and report it in a peer reviewed journal. I have written thousands of words above to try to answer your questions and you come back with some assertion that models are "tweaked." OF COURSE THEY ARE. All but the simplest fundamental "toy" models are tweaked by observation. No model falls off the shelf and is correct. All models have uncertainty. Go dig up the data yourself. I think you have the basis for a good paper and I don't want to write one here.

How can you support CO2 forcing based upon NO data?
PinkElephant
5 / 5 (3) Jul 13, 2010
This statement by the clown, which I've now seen repeated several times, demonstrates a fundamental (and probably deliberate, given his track record) misunderstanding of the greenhouse effect:
How much energy is absorbed by CO2 in the atm?
The greenhouse effect is not due to CO2 absorbing photons and thus heating up the atmosphere. It is due to CO2 absorbing photons, then re-emitting the absorbed energy toward the ground. Ultimately, it is the planetary surface that experiences an increased photon flux: to the flux that comes directly from the sun, is added the flux of outbound infrared that is partially redirected back toward the surface by the greenhouse gases (which, unlike direct solar flux, happens at all times of day.) Thus, global warming is caused by a buildup of heat at the planetary surface, rather than directly in the air. The heat is then transferred from surface to air by sensible transport (i.e. direct physical contact), and up into the atmosphere via convection.
marjon
2.3 / 5 (3) Jul 13, 2010
CO2 is not the only gas that absorbs photons. H2O absorbs much more.
The source of the outbound IR energy is the inbound IR energy. How can a few ppm delta of CO2 such great worry?
It is due to CO2 absorbing photons, then re-emitting the absorbed energy toward the ground.

Those evil little CO2s point their photons at the ground? No, they emit in a 4pi steradian solid angle, most going up, some going down.
I understand the mechanism, I just don't buy the magnitude of the effect and the ONLY justification are tweaks to highly uncertain global climate models.
Recent observations seem to be bearing this out as CO2 seems to be rising, but mean temperatures are falling.
Caliban
5 / 5 (2) Jul 13, 2010
Recent observations seem to be bearing this out as CO2 seems to be rising, but mean temperatures are falling.


Recent observations bear nothing of the sort out- as, contrary to what you have just said, BOTH CO2 emissions and Median Temperatures are in positive trends.

Saying that something IS the way you want it to be does not MAKE IT SO.

This is why everyone eventually gets around to addressing you with such contempt and derision, marjon- what you want to be so obviously overrides any other consideration- especially the facts.
marjon
1 / 5 (1) Jul 13, 2010
"According to data from the National Space Science and Technology Center in Huntsville, Ala., the global high temperature in 1998 was 0.76 degrees Celsius (1.37 degrees Fahrenheit) above the average for the previous 20 years.

So far this year, the high has been 0.42 degrees Celsius (0.76 degrees Fahrenheit), above the 20-year average, clearly cooler than before.

"Climate experts say the 1998 record was partly caused by El Nino, a periodic warming of tropical Pacific Ocean waters that affects the climate worldwide.

"The temperature peak in 1998 to a large extent can be attributed to the very strong El Nino event of 1997-98,"

Christy added, however: "Our ignorance of the climate system is still enormous, and our policy makers need to know that . . . We really don't know much about what causes multi-year changes like this."

Read more: http://www.mcclat...tbxToAZT

PinkElephant
5 / 5 (2) Jul 13, 2010
The source of the outbound IR energy is the inbound IR energy.
Not exactly. Since the surface of the Earth is not the same temperature as the surface of the sun, the incoming vs. outgoing light have rather different black-body envelopes. Of the incoming solar energy, a much smaller percentage gets snagged by CO2 (because a lower fraction falls within CO2's relevant absorption bands), than the percentage of the outgoing earth-emitted heat (which has a much lower frequency at the apex of its emission envelope.)
Those evil little CO2s point their photons at the ground? No, they emit in a 4pi steradian solid angle, most going up, some going down.
Actually, only slightly more than 50% are directed up and sideways out of the atmosphere, whereas the only slightly less than 50% remainder reach the ground: think of it roughly as the two hemispheres of a single sphere. So, "most" vs. "some" is highly misleading language. And that's before we discuss optical opaqueness.
PinkElephant
5 / 5 (2) Jul 13, 2010
So far this year, the high has been 0.42 degrees Celsius (0.76 degrees Fahrenheit), above the 20-year average, clearly cooler than before.
Which 20-year average is being discussed? The 20 years that preceded 1998, or the 20 years preceding 2009 (the "this year" referenced here)? Cute, too, since 2009 was a La Nina year. One has to wonder what the figures will be for 2010, comparing El Nino to El Nino. Still not apples-to-apples (since the 1998 El Nino was freakishly strong, whereas this year it was merely typical). But, at least not as blatantly apples-to-oranges as your referenced piece of "journalism".
PinkElephant
5 / 5 (2) Jul 13, 2010
Oh, and let's also note that in 2010 we've just barely started to emerge from a deep solar minimum.
marjon
1 / 5 (2) Jul 13, 2010
Oh, and let's also note that in 2010 we've just barely started to emerge from a deep solar minimum.

But it CO2 is the ONLY cause according to AGWites. Now you say the sun has a role?
So, "most" vs. "some" is highly misleading language. And that's before we discuss optical opaqueness.

Depends upon altitude, no?
If the total energy radiating the earth did not balance the total incident, the earth would be warming quite rapidly.
Caliban
5 / 5 (1) Jul 13, 2010
So far this year, the high has been 0.42 degrees Celsius (0.76 degrees Fahrenheit), above the 20-year average, clearly cooler than before.

"Climate experts say the 1998 record was partly caused by El Nino, a periodic warming of tropical Pacific Ocean waters that affects the climate worldwide.


Any way you slice it, mangy- a partial year temperature record does not a trend make.

Here's the stuff you were looking for- and be sure to pay close attention to the graphs and captions- I know that'll be considerably easier for ya:

http://www.giss.n...0100121/

Note that 2009 was the SECOND warmest on record in the southern hemisphere, and only just missed being a record warm year globally, and that the first decade of the new millenium is the WARMEST ON RECORD.
marjon
1 / 5 (3) Jul 13, 2010
Any way you slice it, mangy- a partial year temperature record does not a trend make.

That's right, and neither does a 400 year record as the NSF said.
How about 1000 years? What caused the MWP? SUV's?
PinkElephant
5 / 5 (3) Jul 13, 2010
But it CO2 is the ONLY cause according to AGWites.
Climate science according to the clown... Granted, somewhat funny, but I'm not laughing out loud yet. Come on, try harder.
If the total energy radiating the earth did not balance the total incident, the earth would be warming quite rapidly.
Which it is doing, and which is the whole point of the discussion. Or did you think warming up a planet ought to be as fast as boiling a pot of tea? We're dealing with a lot of inertia here: the oceans are vast and deep, and heat capacity of H2O shockingly high.
What caused the MWP? SUV's?
But the sun isn't responsible this time, as TSI hasn't gone up since 1950:

http://www.climat...m#Recent

Note the entire TSI range between LIA and today is ~3 W/m^2. Compare and contrast:

http://en.wikiped...eCO2.png

That's just CO2 alone, not counting water vapor feedback (or any other feedbacks...)
Caliban
5 / 5 (2) Jul 13, 2010
Any way you slice it, mangy- a partial year temperature record does not a trend make.

That's right, and neither does a 400 year record as the NSF said.
How about 1000 years? What caused the MWP? SUV's?


Perfect example of your strategy, Mangy- when faced with a fact that you have no legitimate response for except to admit that you are INCORRECT, and to begin to have to modify your position, you simply either:
a.) duck, and brandish another talking point, or
b.) reassert your original assertion.
This is what makes it certain that your agenda is something entirely else than simple "Spirited Debate".

At any rate, whatever it is you are trying to prove, your doing a damned shitty job of it- unless, that is, you are trying to prove that you are a moron, in which case- you win the prize.

PinkElephant
5 / 5 (3) Jul 13, 2010
Now, I'll grant the clown this: /IF/ the Sun just up and decided to dim and give us even less radiation than during the LIA for a few centuries straight, then the AGW would neatly cancel out with the Sun's variation and actually keep global climate stable at approximately today's state.

Get out your prayer beads and trance drums, let's form a circle and commence our collective supplication to the Sun God(s).

Hey, and why not? Bet the farm on hope and prayer, because God(s) forbid we introduce any accountability for externalities into our apparently fragile, inflexible, and non-adaptable economic system -- or upset the blissful status quo of our established industrial elites.

AGW doesn't matter, just like deficits don't matter. Really, nothing matters. By the time TSHTF, we'll all be dead of old age anyway. Let the grandkids reap the $@#%storm...
Caliban
5 / 5 (2) Jul 13, 2010
If it comes to that, PE, the former does seem more likely than the latter, does it not?
Skeptic_Heretic
5 / 5 (2) Jul 16, 2010
Any way you slice it, mangy- a partial year temperature record does not a trend make.

That's right, and neither does a 400 year record as the NSF said.
How about 1000 years? What caused the MWP? SUV's?

Can you tell us the complex chemical and physical processes that started the MWP? Can you tell us how those processes fit into the current observations?

If you can't substantiate your hypothesis that the MWP and current observations are caused by the same or similar processes, then the reliability of your statement is more suspect and less accurate than AGCC.

I('m interested to hear your reply on this topic.