I’m offline this weekend with travel and other projects.
Discuss anything with limits of the WUWT site policy. This will remain a “top post” for the weekend. Some auto-scheduled stories will appear below this one. Don’t forget to observe Earth Hour Human Achievement Hour 8:30 PM local time in your time zone.
@Bomber_the_Cat
Sorry I made you angry. And thanks for giving more detail on your calculations. I do have a genuine problem understanding. I am not a physicist so I am not familiar with making all these calculations myself as you require me to do. (That’s why I keep asking for a simple comprehensive scientifically sound explanation of the greenhouse effect.)
My understanding of blackbody radiation is as follows: the higher the temperature, the shorter the wavelength of the emission peak. But nevertheless: the higher the temperature the more it radiates at all wavelengths.
My understanding of the role of the distance of the radiant source is the following: The further away the radiant source the less radiation is received by a unit area (inverse square law). But: the radiant source does not get dimmer by distance it just gets smaller.
Everyday life example: streetlights at night. Contrary to common believe the more distant streetlights are not dimmer, they are just smaller. (If this were the case we would all walk in our own spotlight and the world around us would be dark.) Thats why I came up with checking your calculation against the space the sun occupies on the sky. And from that calculation I figured that your claim that the earth is 4 million times brighter at its peak emission wavelength than the sun is a little bit too high. (Any sources besides your calculation? I tried to find it, but did not succeed.)
You are not right when you say: “I would check these calculations if I had doubts, but Bair Polaire simply says he doesn’t believe it. What doesn’t he believe?”
I gave my reasons for not believing before and I give them here. I even offered a quick plausibility check. Maybe I am wrong. No problem. I’m here to learn. But please don’t make hurting assumptions about my motives just because I don’t agree with you or don’t understand you. Thank you.
Bair Polair
The impression you give is that the goal posts change as you get answers to your earlier questions. I explained that your understanding of Spencers explanation and experiment was incorrect. Spencer certainly does not believe that a cold object can heat a hotter object.
You said earlier
“2. I understand gases absorb and emit at the same wavelengths. The sun is much brighter than the earth at all wavelength even infrared. And the sun has always more than half of the atmospheric CO2 in view. Why then is CO2 not considered to shield the earth more from the suns heat than warming the earth (actually just slowing heat loss) through a little back radiation from a dim source?
3. Most back radiation from the sky is probably due to clouds and water vapor. How sure are we that we can measure the back radiation from increase in CO2?
4. Is there a good everyday life example of reduced heat loss through back radiation?”
On 2 a few people explained to you that C02 is transparant to the solar energy. You disputed that. I mentioned Wiens displacement law. And no reply from you but the assumption is you have learnt something.
3. If the amount of C02 increases then backradiation is going to increase because that is just physics. The question though is how much of a difference it makes.
4. Engineers use backradiation calculations to show heat loss reductions from hot to colder surfaces.
http://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html
Are you wanting to come up with an entirely new theory of the universe? Are you saying the scientific work of the last 200 years is wrong? If so google Doug Cotton and Claes Johnson.
Girma says: March 31, 2012 at 11:54 pm
A Fascinating story on the discovery of the causes of Ice Ages
This is the building where Milankovic was a professor.
http://www.bg.ac.rs/img/etf.jpg
Sculpture to the right is of Nikola Tesla, another great Serbian scientist and innovator.
There are two large theatres where Milankovic gave lectures (capacity about 300 each), btw, where I attended lectures many years later, and laboured through numerous exams as these ‘poor souls’ shown here.
Girma says:
March 31, 2012 at 11:54 pm
————————
Thanks for posting Allen’s write-up on Milankovich. A truly remarkable chap he was, living in an era where it was perfectly normal for a scientist to get drunk with a poet friend and to launch a monumental study on the resulting hunch, and when intellectuals took pride in ideas, could ignored politics and continue friendships in the midst of wars.
bair polaire says:
I still don’t understand why CO2 is not heated by the sun directly. Not even a little bit?
What makes you think that? CO2 will absorb inbound Solar radiation within it’s absorption band, and does, over 85% of inbound energy from the sun and outbound energy in the absorption band is already absorbed and indeed this puts a solid cap of the absolute maximum amount of warming that we may experience even if the whole atmosphere was CO2. CO2 will slow the uptake of energy as well as slow the loss, the system will reach equilibrium potentially at a higher temperature but with a reduced temperature range. However CO2 is already doing 85% of the warming it ever possibly can.
If you do the math, it works out to be 5.2 degrees including ALL FEEDBACKS when making the assumption that CO2 is the only driver of the temperature rise (valid in a 100% CO2 atmosphere) for any reasonable concentration of CO2 though it’s not the only driver. For the next doubling I figure this works out to about 0.6 degrees max.
It’s very complicated however, the climate is driven by masses of variables, our atmosphere is a chaotic, open system, with multiple feedbacks working in unpredictable ways. CO2 is only proven to cause warming in experiments in CLOSED, Non-chaotic SYSTEMS. Cooling / Warming of the atmosphere occurs by multiple mechanisms, many more than just radiation. There is in my opinion zero chance of modelling it. CO2 will undoubtably cause some warming but If you want to know what will happen, you should start with observations and work from there.
For example from the little ice age to now there has been about 0.6 degrees of warming. That’s for and increase of about 110 PPM. Now the Australian Government tries to tell me that for the next doubling they think we will get 6 degrees (disregarding that this is above the max that could ever happen even for 100% CO2). So the government reckons then that the next 110PPM rise in CO2 will cause about 2-3 degrees of warming, but if the last 100PPM caused 0.6 (assuming all the rise from the little ice-age to now is CO2 driven which it’s not), and the relationship is logarithmic (each equal rise in CO2 results in less warming) then it follows that the rise for the next 110PPM CO2 rise must be strictly less than the warming due to the last 110 PPM rise, again run the math and you get a max number around 1-1.5 degree for a doubling of CO2. 2-3 degrees is just ridiculous, it is not in any way supported by any observation of how the atmosphere actually behaves. Conclusion : The Australia Government is WRONG by a factor of about 5!
Add this to the fact above that adding thermal resistance to the atmosphere serves to reduce the temperature range (lower highs, and higher lows) and you have the recipe for a pretty productive climate if the earth did warm – but unfortunately it probably wont 🙁
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I want you to think about something else, by 2050 the Australian Government at the rate they are spending it will have spent $100 Bn of taxpayer money on this farce. If that money went to feeding the starving millions how many lives would be saved on this earth. If the corn that is turned into ethanol to burn in your car, was sent to africa instead how many deaths would have been prevented.
Finally, at a carbon price of only $40 per tonne, it becomes more cost-effective to burn flour to produce electricity than coal (similar calorific value – look it up, some great videos on you-tube) – flour, a staple of life, is renewable and can be produced from most carbohydrates (potato, wheat, corn, rice) – this will become viable WELL BEFORE TRADITIONAL RENEWABLES BECOME COST EFFECTIVE and coal station boilers could easily be adapted to run on it – Think about the morality of that before you start agreeing to tax carbon dioxide. Burning food for fuel is morally corrupt!
Bob
Real Climate has posted an appropriate April Fool’s Joke:
Stefan Rahmstorf at ‘Real Climate’ reports that the ‘Wrong sign paradox’ is due to a widespread climate modeling FORTRAN variable called “I CHEAT!”
http://www.realclimate.org/index.php/archives/2012/04/wrong-sign-paradox-finally-resolved/
A group of Dutch and US scientists, led by Harry Van den Budenmeyer (Utrecht University), has now proposed a surprising explanation. “At first I did not want to believe it”, Van den Budenmeyer explained to RealClimate, “but once we started to pursue this, things just fell into place”.
The story goes back to the late 1980s or early 1990s (the exact date has not been traced back yet), when a German climate modeller had persistent problems with results of obviously the wrong sign in his model. He was unable to track down the error, so instead he introduced a FORTRAN integer variable called ICHEAT (sorry to get a bit technical, but you really need to understand this) into his computer code, assigned it the value -1 and simply multiplied unruly results by ICHEAT wherever they occurred in his code. Once he’d find the real problem, he would only need to set ICHEAT to +1 and the code would be correct again. But he never got round to fix the problem, his model performed very nicely and over time he forgot about it.
What he did not consider, perhaps understandably at the time: useful computer code spreads like a virus amongst scientists. The code was free for download, hundreds of other scientists started to use it and many only used bits and pieces – nobody ever starts writing scientific code from scratch if colleagues have already solved aspects of the task at hand and the code is free.
“At first we were really puzzled when we found a piece of code with ICHEAT that was used in our lab for climate analysis”, says Van den Budenmeyer. “But once we discovered what it was we started to search more systematically and ask colleagues, and by now we’ve found the ICHEAT bug not just in different European countries but also in California, New York, Sydney and even a Chinese climate centre. We’ve only begun to explore the implications, but I am sure that a lot of the wrong sign paradox that has plagued our science thus far will just go away.
@Andrew Judd
Do you want to understand??? Or do you want to falsify without learning?????
I don’t want to falsify anything. I just try to ask precise questions. Because after all my googleing and reading blogs and scientific papers I have to admit – ad this was my first sentence – I still don’t really understand the greenhouse effect.
Everything you say about radiation and CO2 I have read before. I don’t doubt it.
It would just help me if you could give me a rough estimate of the percentages involved.
1. What percentage of the total energy the earth is radiating towards the atmosphere is absorbed by CO2? The absorption/emission bandwidths of CO2 are rather small and not at the emission peak of the earth. Plus the CO2 might get input from other sources like the sun and the rest of the atmosphere.
2. What percentage of that energy received from the surface is re-emitted by CO2 molecules towards earth?
3. What is the effect of this back and force radiation exchange regarding the temperature of the surface? Time frames? When is this effect strongest? Day, night etc.? (As Bobl pointed out: most likely it makes the climate a little warmer on average but less extreme. Do you agree?)
4. What about my “bonus question”: The lower and warmer 50% of CO2 in the atmosphere radiate mostly upwards. Why does this not result in cooling?
Don’t get angry. I’m just trying to learn. If you yell at me and ridicule me I might better give up.
I’m on an open thread roll here. Here’s my contribution.
The IPCC has already telegraphed its intentions: “sustainable development.” The good news is that it realized that the science is junk, that it has been exposed by skeptics and that it needs to retreat gracefully. On ther hand, by switching battles they will pull the rug under the feet of this and similar sites. They have the money, they have the media, they have the support of governments and some industries. They will try to kill the blogosphere with regulations and controls, knowing that it was the unexpected appearance of the Web and the proliferation of independent thinkers with an instant internation reach that killed their environmental scam. Things don’t look too good.
bair polaire says:
April 1, 2012 at 12:56 am
“Bonus question: The lower 50% of CO2 in the atmosphere is warmer than the upper 50%. Most of the radiation goes up not down. Why than is a doubling of CO2 not considered to speed up the cooling of the earth? Radiation is faster than conduction.”
Without greenhouse gases, the radiation would make it instantly to space. That’s why adding greenhouse gases slows down the radiative cooling through absorption and re-radiation. This effect is of course nearly saturated after you have achieved an average of ONE absorption and re-emission per photon, after that, adding more greenhouse gases changes the behaviour only very slightly.
It is this very slight change that according to the international AGW reserach funds recipient mafia will trigger a catastrophy.
New Topic:
Help, Everyone – I had a computer change, and now my Internet Explorer cannot show whatever type of applet / image is used to explore daily global temps at this website:
http://discover.itsc.uah.edu/amsutemps/
-Can someone tell me what program or app is used for the graph?
Also – can someone put a note abt how temps were for March 2012? Compared to recent several years, were they low or high?
Bair Polaire
Lets start with the bonus question first. The C02 does result in cooling of the heated atmosphere. If the GHG’s were not cooling the atmosphere it would be impossibly hot at altitude instead of being cold at altitude where it matters for humans.
Think about it please. Just once at least.
1. The surface is continually heating the colder atmosphere.
2. The atmosphere is continually cooling by emitting radiation in all directions.
3. The surface receives some of this radiation from the cold atmosphere. But this means some of the energy from the surface heated by the sun has not passed thru the atmosphere to outerspace. If you are heating something and you reduce the cooling it becomes hotter.
Dont please ask me for minute details about this. What part of the above can you not understand?
If you heat an object and place a cold object next to the heated object then the hot object heats the cold object and *both* objects become warmer between each other. If the cold object was not continually cooling it would just get hotter and hotter and hotter.
The atmosphere does not get hotter and hotter and hotter when it is heated by the surface because the atmosphere is continually cooling because it is emitting radiation to space.
If the atmosphere was not able to emit radiation it would rise in temperature at altitude to tens of thousands of degrees and would still carry on getting hotter until the atmosphere was entirely spread beyond the gravitational pull of the earth.
bair polaire
Q 1 – As I said in my previous post CO2 intercepts (at current concentration) about 85% of incident energy in is absorption band. About 15% reaches the ground. The Atmosphere is pretty opaque at the wavelengths.
Q2. one could assume about 1/2 if the radiation is isotropic (all in one direction) and no reflection/refraction occurs and I understand this is the assumption.
Q3. This question is not satisfactorilly answered, but you can reach some conclusions about this. Since CO2 is a well mixed gas (well it’s not really but lets assume it is) we would expect the effect to be uniform. If we model the CO2 as a thermal resistance or lag, then we would expect the effect to be uniform and acting at all times, however the direction of energy flow and the rate would depend on the time of day. The reason this isn’t quantifiable though is that CO2 is not the only gas acting, humidity (water vapour), evaporation rates and clouds also moderate energy flows. This factors in to the all important discussion on FEEDBACKS.
Bonus Question. I don’t think that’s right, I am pretty sure CO2 radiates isotropically, but in the lower atmosphere convection dominates as the cooling mode, hot air rises, so most of the heat in the lower atmosphere moves upward. Also when the surface is heated by CO2 wavelengths the surface gets hotter, the rate of convection increases, but importantly thermodynamics tell us that the hotter surface reradiates this energy faster at all wavelengths, most of this energy then can be radiated to space in non CO2 wavelengths. More than 80% of the heating due to back radiation is immediately lost this way. Part of the failure of CO2 theory is that the models forecast that radiation to space from the hotter surface due to CO2 warming will be less (because the CO2/H2O is trapping it), and therefore the radiative balanced has change such that the ratio of incoming to outgoing is higher (and the surface therefore must get hotter – see my frost posting remember it is the ratio of gain to loss that determines the temperature). In actual fact satellite measurements show this doesn’t happen and that emission from the surface increases as the surface temperature increases (thermodynamics lives to see another day). This suggests the models are wrong, and the increased CO2 is not affecting the balance of gain to loss much at all.
Interesting to see how the Arctic and Antarctic are refusing to kowtow to the Warmista’s needs, maybe it is the wrong sort of ice, or cold because of course, it can’t be a modelling fault.
It is going to be a fascinating melt season in the Arctic, when it starts!
I used to keep an eye on it over at Neven’s site but he’s gone all politico and seems to be moving away from the ice science, well enough for a worry that observer bias could be creeping in over there.
thelastdemocrat says:
………
Download and install Java software.
Bair Polair,
If you want to improve your understanding of how GHGs, including CO2, operate, I suggest reading the comments by rgbatduke in the following thread:
http://wattsupwiththat.com/2012/03/27/ramanathan-and-almost-black-carbon/
The Heartland Institute announces a new plan for keeping their documents private. In the future, they will send only hardcopy to their board members printed on a new printer they acquired today
http://www.thinkgeek.com/stuff/looflirpa/shrinter.shtml
Can anyone tell me what, exactly, is the deal between Pielke Sr and Jr? I keep getting conflicting ideas about these two. Jr, for example, seems to me to sometimes be on both sides of the fence at once.
Here is an article that seems pertinent to the argument that skeptics are “anti-science”:
http://news.yahoo.com/cancer-science-many-discoveries-dont-hold-174216262.html
Otter says:
April 1, 2012 at 8:31 am
“Can anyone tell me what, exactly, is the deal between Pielke Sr and Jr? I keep getting conflicting ideas about these two. Jr, for example, seems to me to sometimes be on both sides of the fence at once.”
Sr. is more into the hard science questions, Jr. more into the social or science communications aspects so he’s usually making a more political point.
Michael Kelley says:
April 1, 2012 at 8:37 am
“Here is an article that seems pertinent to the argument that skeptics are “anti-science”:
http://news.yahoo.com/cancer-science-many-discoveries-dont-hold-174216262.html
”
Nothing exciting. Sturgeon’s Law – when asked why 95% of SF is crap he answered “95% of everything is crap.”
Wind power folly in Nevada:
http://www.lasvegassun.com/news/2012/mar/30/nv-energy-windmill-program-generates-rebates-littl/
Looks like as the latest Forbush decrease has confirmed the Svensmark’s hypothesis.
http://www.vukcevic.talktalk.net/Ap-Cl.htm
@Andrew Judd
Thanks for getting back to my questions. I perfectly understand all of what you say. I’ve read this many times before. It’s usually not disputed and I don’t doubt it.
Now you say:
If you heat an object and place a cold object next to the heated object then the hot object heats the cold object and *both* objects become warmer between each other.
And this I don’t believe. “Both objects become warmer between each other?” Most certainly not. The colder object gets warmer, but the warmer objects does not get warmer, it still gets colder. It just cools a little slower than without the colder (and warming) object nearby.
Maybe I am misreading your statement. Maybe you want to say: If you continually heat an object and place a cold object nearby, it warms the cold object and at a certain point, when the colder object is warmer than the background, the warmer – and still continually heated – object can get even a little warmer than before.
With this I agree. (Like the earth being continually heated by the sun and is now getting even a little warmer because the nearby CO2 is already warmer than space and now we get more CO2.)
Then you say: Dont please ask me for minute details about this. Why not? This is exactly what I want to understand. What are the percentages? What do we really know about how big the effect is? Does the heat content of CO2 compared to the rest of the atmosphere play a role? Is CO2 absorbing incoming solar radiation? (You say it is transparent, Bomber says it’s negligible, gbaikie points to a graph that shows its absorbing something and Bobl says yes, a lot – around 85% of all it can take.) There are many more relevant questions. Some of them are not settled.
We are asked to risk the future of our societies to prevent this back radiation effect from CO2 and I shall not ask for details? Not even rough estimates?
I don’t think I can agree to this.
Fallout from Fakegate as Gleick’s disinformation campaign continues to harm the Heartland Institute:
http://www.globalpost.com/dispatch/news/green/global-warming/120331/heartland-institute-gm-yanks-funding-says-global-warming-r
Anyone know of updates on Fakegate and Gleick?