The warming of the earth due to CO2 is a very important subject. Thousands of articles have been written about this "Climate sensitivity". All theoretical, not based on experimental fact.
Why hasn't some university performed the simple task of testing this hypothesis "That doubling CO2 in the atmosphere will cause a serious increase in absorbed earth IR radiation, and thus serious global warming."
It would be a rather simple study, if one has the tools. We are spending trillions on a belief in an untested thesis, but won't spend a few thousands to test it!
I am an old PhD engineer, who did not base his designs on untested hypotheses.
And explain what's wrong with the proven physics there. Not here. I don't want every article to be full of comments re-explaining the certain aspects of atmospheric physics to people who don't understand it.
I can not comment on his math, except that it is all theoretical and a bit nebulous. There are a lot of assumptions. There are dozens of such calculations, all above my pay grade. But they do not seem to be in agreement. My complaint is that no one has been willing to test the theory in physical experiments!
There is one paper that reports a study showing no difference in absorption, but it is not totally clear.
Science is based on making an hypothesis and then verifying it in practice.
Einsteins hypothesis that gravity can bend light was only accepted when proven by observing the time of passage of star behind the sun.
I have written a little booklet "Carbon Dioxide-Not guilty" and would send you a copy if I could attach it here. It is on Kindle for 99c. Or send me (bobhiseyatcomcast.net) an email address and i will send a copy. Its in the public domain.
By the way. The NASA produced (but not by satellite) exhaustive study of transmittance/absorption of the atmosphere in the IR region can be found at NASA technical memorandum 103957 hidden in Appendices E and F. A handy condensed version was to be found on the site of the Gemini IR astronomy program, but now only a copy exists in my little booklet.
"It would be a rather simple study, if one has the tools. We are spending trillions on a belief in an untested thesis, but won't spend a few thousands to test it! ... I can not comment on his math, except that it is all theoretical and a bit nebulous. There are a lot of assumptions. There are dozens of such calculations, all above my pay grade."
Bob, it sounds like you're saying you don't understand why the field is currently approached the way it is. And, at the same time, you don't understand the math, which is pretty fundamental to understanding the science.
if you don't understand the existing science, the right thing to do is to first *work to understand it*. Any meaningful experiment you can do for a few thousand dollars has looooooong ago already been done and re-done. Are you familiar with the work from the early 1900s to 1950s?
Rather than trying to get other people to do things your way, you need to work to understand the existing approach - and when you do, you'll find that your concerns have already long ago been addressed. But nobody's going to listen to a retired PhD engineer who hasn't put in the work to catch up. You, like everyone else, have to put in the hours required to understand the existing work before you can provide meaningful comments.
Geophysics and astrophysics are two scientific disciplines that are unable to benefit from controlled experiments. Clearly gravity on the planetary scale can't be duplicated in a lab setting and neither can complex Coriolis effects on a spinning planet with inwardly directed g-forces. It's really what sets climate science apart and explains why climate research advances at a glacially slow pace.
Ben: Part of the problem is that climate scientist want to over-simplify the problem so that people think they understand it. They only want to talk about GHGs trapping heat by absorption. When someone learns GHG's also emit thermal IR, they recognize that part of the story is missing and become skeptical. In truth, doubling CO2 will double absorption by CO2 and double emission from CO2, To a first approximation, these changers cancel. However, when you get to the second approximation, doubled CO2 absorbs more upward radiation that is emitted where it is warmer and it absorbs downward radiation that is emitted from higher in the atmosphere. If we didn't have a temperature gradient in the atmosphere, GHGs would not produce a greenhouse effect - and they don't in Antarctica where there is no temperature gradient. By over-simplifying, climate scientists lost people like Robert, who know enough to realize something is wrong, but are misled by others before they can figure it out.
Hi Frank. There is no temperature gradient in the atmosphere in the Antarctic? Maybe these people need to redo their radiosonde measurements -https://www.mdpi.com/2073-4433/10/7/365
Michael: I oversimplified somewhat. In most of the troposphere, temperature decreases about 6.5 degC for every 1 km increase in attitude until you reach the tropopause or about 65 degC total over the first 10 km. In Figure 2 of your paper, over the same 10 km beginning at the surface, the temperature falls 20, 12, 0 and 10 degC in spring, summer, autumn and winter. This change is dramatically smaller than elsewhere on the planet. In the two references below, scientists used radiative transfer calculations through the Antarctic atmosphere at various times of the year and those calculations don't stop at 10 km. In these calculations, changes in GHGs at low altitudes (high pressure) are more important than at high altitudes, because there are fewer GHG molecule per unit volume at high altitudes. Absorption is relatively independent of temperature, but emission increases dramatically with temperature. Both authors conclude there is a very modest "negative" greenhouse effect on the average in Antarctica.
Schmithüsen, Holger; Notholt, Justus; König-Langlo, Gert; Lemke, Peter; Jung, Thomas (16 December 2015). "How increasing CO2 leads to an increased negative greenhouse effect in Antarctica". Geophysical Research Letters. 42 (23): 10, 422–10, 428. Bibcode:2015GeoRL..4210422S. doi:10.1002/2015GL066749.
Sejas, Sergio A.; Taylor, Patrick C.; Cai, Ming (11 July 2018). "Unmasking the negative greenhouse effect over the Antarctic Plateau". npj Climate and Atmospheric Science. 1 (1): 17. doi:10.1038/s41612-018-0031-y. PMC 7580794. PMID 33102742.
I probably shouldn't have gotten so far off the topic of this post. I was simply trying to make it clear that simplistic ideas about GHGs "trapping" heat by absorption are inadequate. I struggled for months, perhaps even years trying to rationalize why doubled absorption and doubled emission from doubling CO2 didn't cancel each other. Then our host showed me the proper equations and "everything" became clear to me. However, I've found that these equations don't "talk" to other people as the clearly as they explain things for me. I was so thrilled I eventually wrote the above Wikipedia article on Schwarzschild's Equation for Radiation Transfer, but I'm not sure many appreciate it.
"Part of the problem is that climate scientist want to over-simplify the problem so that people think they understand it. They only want to talk about GHGs trapping heat by absorption. When someone learns GHGs also emit thermal IR..."
*All* materials emit radiation according to their temperature and optical spectra. This is the basis of the Stefan-Boltzmann Law, which is single most important law of physics underlying climate science. This is something college students typically learn in their first week or two in an introductory course on climate science. It's something you'll learn early in *any* course involving radiative energy transfer.
Climate scientists aren't hiding this, and no, they aren't oversimplifying it, and no, the increased radiative emission from CO2 doesn't make up for the increased radiative absorption (important: half of all the re-emission is downwards, back towards the Earth). Crack an introductory textbook on the subject, and you'll find your objection addressed in the first few chapters.
This is part of the basic, basic, basic mechanics of how climate works, so it's probably a good candidate for the Digression thread. If you want to talk more about it, I'll meet you over there:
There is a fundamental problem with emission of radiation when it is presented as emission of blackbody radiation in basic undergraduate courses. Let's say I have some gold and it emits blackbody radiation (or graybody radiation with emissivity less than 1). Now pound that gold into a thin layer. Does it still emit radiation of blackbody radiation? What happens when it becomes only a few atoms thick. Are there still enough gold atoms to emit like a blackbody? What if it is thin enough to see through, and some of the radiation coming out of it was emitted by objects that are behind. Does it still emit blackbody radiation?
Emission MUST depend on the number of molecules that are doing the emitting. We only get blackbody radiation coming out of something when there are enough emitting/absorbing molecules present that emission and absorption have come into an equilibrium before radiation leaves the surface. That assumption of equilibrium is what Planck used to derived Planck's Law.
Emissivity is a phenomena that develops as light passes through a surface and some is reflected inward. Thus emissivity equal reflectivity/absorptivity (Kirchhoff's Law). In the case of a gas (which don't have a surface and therefore has emissivity of unity), people cheat and refer to "optically-thick layers" of atmosphere that emit blackbody radiation and "optically-thin layers" of atmosphere that emit in proportion to the concentration of GHG's they contain. The latter case is the one that is always correct, but if you stack enough optically thin layers on top of each other, they will eventually absorb enough of the radiation emitted by other layers that they will emit radiation like a blackbody. The earth's atmosphere isn't thick enough for wavelengths in the "atmospheric window" to reach equilibrium. More than 50% of photons with those wavelengths pass through directly to space. The blackbody spectrum that reaches space at those wavelengths is the blackbody spectrum that was emitted by the surface of the planet.
The nice thing is that Schwarzschild's Equation takes care of these problems automatically by numerically integrating the emission and absorption of a large number of OPTICALLY THIN layers. This equation can be summarized to say that radiation traveling through a medium is modified by emission and absorption so as to approach blackbody intensity at all wavelengths. The RATE (with distance traveled) at which radiation approaches blackbody depends on the concentration of absorbing/emitting molecules and how strongly they interact with the radiation at a given wavelength (absorption cross-section) go a given wavelength. Beer's and Planck's Laws are corollaries of the Schwarzschild equation that apply in the incoming radiation is so intense that emission is negligible and when emission and absorption are in equilibrium.
So when basic physics discusses emission of blackbody radiation, they are only referring to dense materials that have some thickness. For liquids (which may be transparent) and gases, the situation can be more complicated.
The warming of the earth due to CO2 is a very important subject. Thousands of articles have been written about this "Climate sensitivity". All theoretical, not based on experimental fact.
Why hasn't some university performed the simple task of testing this hypothesis "That doubling CO2 in the atmosphere will cause a serious increase in absorbed earth IR radiation, and thus serious global warming."
It would be a rather simple study, if one has the tools. We are spending trillions on a belief in an untested thesis, but won't spend a few thousands to test it!
I am an old PhD engineer, who did not base his designs on untested hypotheses.
Nor should our government.
Robert,
Please go over to this page - Understanding Atmospheric Radiation and the “Greenhouse” Effect – Part Six – The Equations:
https://scienceofdoom.com/2011/02/07/understanding-atmospheric-radiation-and-the-%e2%80%9cgreenhouse%e2%80%9d-effect-%e2%80%93-part-six-the-equations/
And explain what's wrong with the proven physics there. Not here. I don't want every article to be full of comments re-explaining the certain aspects of atmospheric physics to people who don't understand it.
Hi
I can not comment on his math, except that it is all theoretical and a bit nebulous. There are a lot of assumptions. There are dozens of such calculations, all above my pay grade. But they do not seem to be in agreement. My complaint is that no one has been willing to test the theory in physical experiments!
There is one paper that reports a study showing no difference in absorption, but it is not totally clear.
Science is based on making an hypothesis and then verifying it in practice.
Einsteins hypothesis that gravity can bend light was only accepted when proven by observing the time of passage of star behind the sun.
I have written a little booklet "Carbon Dioxide-Not guilty" and would send you a copy if I could attach it here. It is on Kindle for 99c. Or send me (bobhiseyatcomcast.net) an email address and i will send a copy. Its in the public domain.
By the way. The NASA produced (but not by satellite) exhaustive study of transmittance/absorption of the atmosphere in the IR region can be found at NASA technical memorandum 103957 hidden in Appendices E and F. A handy condensed version was to be found on the site of the Gemini IR astronomy program, but now only a copy exists in my little booklet.
"It would be a rather simple study, if one has the tools. We are spending trillions on a belief in an untested thesis, but won't spend a few thousands to test it! ... I can not comment on his math, except that it is all theoretical and a bit nebulous. There are a lot of assumptions. There are dozens of such calculations, all above my pay grade."
Bob, it sounds like you're saying you don't understand why the field is currently approached the way it is. And, at the same time, you don't understand the math, which is pretty fundamental to understanding the science.
if you don't understand the existing science, the right thing to do is to first *work to understand it*. Any meaningful experiment you can do for a few thousand dollars has looooooong ago already been done and re-done. Are you familiar with the work from the early 1900s to 1950s?
Rather than trying to get other people to do things your way, you need to work to understand the existing approach - and when you do, you'll find that your concerns have already long ago been addressed. But nobody's going to listen to a retired PhD engineer who hasn't put in the work to catch up. You, like everyone else, have to put in the hours required to understand the existing work before you can provide meaningful comments.
Shades of:
https://xkcd.com/793/
Geophysics and astrophysics are two scientific disciplines that are unable to benefit from controlled experiments. Clearly gravity on the planetary scale can't be duplicated in a lab setting and neither can complex Coriolis effects on a spinning planet with inwardly directed g-forces. It's really what sets climate science apart and explains why climate research advances at a glacially slow pace.
Ben: Part of the problem is that climate scientist want to over-simplify the problem so that people think they understand it. They only want to talk about GHGs trapping heat by absorption. When someone learns GHG's also emit thermal IR, they recognize that part of the story is missing and become skeptical. In truth, doubling CO2 will double absorption by CO2 and double emission from CO2, To a first approximation, these changers cancel. However, when you get to the second approximation, doubled CO2 absorbs more upward radiation that is emitted where it is warmer and it absorbs downward radiation that is emitted from higher in the atmosphere. If we didn't have a temperature gradient in the atmosphere, GHGs would not produce a greenhouse effect - and they don't in Antarctica where there is no temperature gradient. By over-simplifying, climate scientists lost people like Robert, who know enough to realize something is wrong, but are misled by others before they can figure it out.
Hi Frank. There is no temperature gradient in the atmosphere in the Antarctic? Maybe these people need to redo their radiosonde measurements -https://www.mdpi.com/2073-4433/10/7/365
Michael: I oversimplified somewhat. In most of the troposphere, temperature decreases about 6.5 degC for every 1 km increase in attitude until you reach the tropopause or about 65 degC total over the first 10 km. In Figure 2 of your paper, over the same 10 km beginning at the surface, the temperature falls 20, 12, 0 and 10 degC in spring, summer, autumn and winter. This change is dramatically smaller than elsewhere on the planet. In the two references below, scientists used radiative transfer calculations through the Antarctic atmosphere at various times of the year and those calculations don't stop at 10 km. In these calculations, changes in GHGs at low altitudes (high pressure) are more important than at high altitudes, because there are fewer GHG molecule per unit volume at high altitudes. Absorption is relatively independent of temperature, but emission increases dramatically with temperature. Both authors conclude there is a very modest "negative" greenhouse effect on the average in Antarctica.
Schmithüsen, Holger; Notholt, Justus; König-Langlo, Gert; Lemke, Peter; Jung, Thomas (16 December 2015). "How increasing CO2 leads to an increased negative greenhouse effect in Antarctica". Geophysical Research Letters. 42 (23): 10, 422–10, 428. Bibcode:2015GeoRL..4210422S. doi:10.1002/2015GL066749.
Sejas, Sergio A.; Taylor, Patrick C.; Cai, Ming (11 July 2018). "Unmasking the negative greenhouse effect over the Antarctic Plateau". npj Climate and Atmospheric Science. 1 (1): 17. doi:10.1038/s41612-018-0031-y. PMC 7580794. PMID 33102742.
I probably shouldn't have gotten so far off the topic of this post. I was simply trying to make it clear that simplistic ideas about GHGs "trapping" heat by absorption are inadequate. I struggled for months, perhaps even years trying to rationalize why doubled absorption and doubled emission from doubling CO2 didn't cancel each other. Then our host showed me the proper equations and "everything" became clear to me. However, I've found that these equations don't "talk" to other people as the clearly as they explain things for me. I was so thrilled I eventually wrote the above Wikipedia article on Schwarzschild's Equation for Radiation Transfer, but I'm not sure many appreciate it.
"Part of the problem is that climate scientist want to over-simplify the problem so that people think they understand it. They only want to talk about GHGs trapping heat by absorption. When someone learns GHGs also emit thermal IR..."
*All* materials emit radiation according to their temperature and optical spectra. This is the basis of the Stefan-Boltzmann Law, which is single most important law of physics underlying climate science. This is something college students typically learn in their first week or two in an introductory course on climate science. It's something you'll learn early in *any* course involving radiative energy transfer.
Climate scientists aren't hiding this, and no, they aren't oversimplifying it, and no, the increased radiative emission from CO2 doesn't make up for the increased radiative absorption (important: half of all the re-emission is downwards, back towards the Earth). Crack an introductory textbook on the subject, and you'll find your objection addressed in the first few chapters.
This is part of the basic, basic, basic mechanics of how climate works, so it's probably a good candidate for the Digression thread. If you want to talk more about it, I'll meet you over there:
https://scienceofdoom.substack.com/p/digression-3-the-greenhouse-effect
There is a fundamental problem with emission of radiation when it is presented as emission of blackbody radiation in basic undergraduate courses. Let's say I have some gold and it emits blackbody radiation (or graybody radiation with emissivity less than 1). Now pound that gold into a thin layer. Does it still emit radiation of blackbody radiation? What happens when it becomes only a few atoms thick. Are there still enough gold atoms to emit like a blackbody? What if it is thin enough to see through, and some of the radiation coming out of it was emitted by objects that are behind. Does it still emit blackbody radiation?
Emission MUST depend on the number of molecules that are doing the emitting. We only get blackbody radiation coming out of something when there are enough emitting/absorbing molecules present that emission and absorption have come into an equilibrium before radiation leaves the surface. That assumption of equilibrium is what Planck used to derived Planck's Law.
Emissivity is a phenomena that develops as light passes through a surface and some is reflected inward. Thus emissivity equal reflectivity/absorptivity (Kirchhoff's Law). In the case of a gas (which don't have a surface and therefore has emissivity of unity), people cheat and refer to "optically-thick layers" of atmosphere that emit blackbody radiation and "optically-thin layers" of atmosphere that emit in proportion to the concentration of GHG's they contain. The latter case is the one that is always correct, but if you stack enough optically thin layers on top of each other, they will eventually absorb enough of the radiation emitted by other layers that they will emit radiation like a blackbody. The earth's atmosphere isn't thick enough for wavelengths in the "atmospheric window" to reach equilibrium. More than 50% of photons with those wavelengths pass through directly to space. The blackbody spectrum that reaches space at those wavelengths is the blackbody spectrum that was emitted by the surface of the planet.
The nice thing is that Schwarzschild's Equation takes care of these problems automatically by numerically integrating the emission and absorption of a large number of OPTICALLY THIN layers. This equation can be summarized to say that radiation traveling through a medium is modified by emission and absorption so as to approach blackbody intensity at all wavelengths. The RATE (with distance traveled) at which radiation approaches blackbody depends on the concentration of absorbing/emitting molecules and how strongly they interact with the radiation at a given wavelength (absorption cross-section) go a given wavelength. Beer's and Planck's Laws are corollaries of the Schwarzschild equation that apply in the incoming radiation is so intense that emission is negligible and when emission and absorption are in equilibrium.
So when basic physics discusses emission of blackbody radiation, they are only referring to dense materials that have some thickness. For liquids (which may be transparent) and gases, the situation can be more complicated.
I added a newarticle on this topic, so people can comment over there.
https://scienceofdoom.substack.com/p/digression-3-the-greenhouse-effect