According to the IPCC, “greenhouse gases” send back to the surface some IR radiation which originally came from the surface, thus increasing the surface temperature:
“The Sun powers Earth’s climate, radiating energy at very short wavelengths, predominately in the visible or near-visible (e.g., ultraviolet) part of the spectrum. Roughly one-third of the solar energy that reaches the top of Earth’s atmosphere is reflected directly back to space. The remaining two-thirds is absorbed by the surface and, to a lesser extent, by the atmosphere. To balance the absorbed incoming energy, the Earth must, on average, radiate the same amount of energy back to space. Because the Earth is much colder than the Sun, it radiates at much longer wavelengths, primarily in the infrared part of the spectrum. Much of this thermal radiation emitted by the land and ocean is absorbed by the atmosphere, including clouds, and re-radiated back to Earth. This is called the greenhouse effect. The glass walls in a greenhouse reduce airflow and increase the temperature of the air inside. Analogously, but through a different physical process, the Earth’s greenhouse effect warms the surface of the planet. Without the natural greenhouse effect, the average temperature at Earth’s surface would be below the freezing point of water. Thus, Earth’s natural greenhouse effect makes life as we know it possible. However, human activities, primarily the burning of fossil fuels and clearing of forests, have greatly intensified the natural greenhouse effect, causing global warming.”
Recall what we discussed in a previous post: in science, what we seek to identify is the physical principle which underlies a phenomenon. By identifying and understanding the underlying principle, we thus understand reality. If we can mathematize the principle and justify it on a-priori mathematical absolutivity, then the phenomenon becomes a scientific Law, such as the Laws of Thermodynamics or Kepler’s Law of Universal Gravitation, or the Laws of Least Action or Least Time. We can also engineer the physical principle and use it to our benefit, to produce products, services, and generally, to create wealth and increase the standard of living of people, etc.
The obvious question: is the underlying principle of the atmospheric greenhouse effect actually defined, anywhere?
All I have to tell you, is that “No, it is not.”
What does the IPCC, the world’s supposedly most scientifically informed organization on climate matters, have to say about the greenhouse effect? Only that it is analogous to, but different from, the glass walls in a greenhouse. That’s no definition of a scientific principle! And yes, that is the sound of my voice laughing!! What the hell does “analogous to, but different from” have to do with stating a scientific principle? Nothing. The IPCC proves that the AGHE can’t actually even be defined. If they could define it, and if anyone could, they would, but they don’t, and never have. As I’ve said elsewhere, the AGHE is an enigma, a comparison of two numbers who’s comparison simply doesn’t have a physically defined meaning at all.
But let’s look into the logic of this explanation by the IPCC a little deeper. First, what do they say about how a real greenhouse functions: “The glass walls in a greenhouse reduce airflow and increase the temperature of the air inside.”
This statement isn’t even correct. Glass walls do indeed reduce airflow, but it is not really the walls which are most important – the IPCC forgot to mention the ceiling. Then they say “and increase the temperature”, which means that the glass walls are the cause of the increase in temperature. Do the glass walls have a source of heat? Do they generate power? They don’t do those things of course, and so it makes no sense to say that the walls “increase the temperature”. The walls are inert objects and have no way of affecting the ambient temperature, in a causal sense, at all. What the walls (and ceiling) do represent is better described as a boundary condition of the physical phase-space; they don’t cause something to happen, but they affect what the actual originating causes have in effect on the system they bound.
What really happens in a real greenhouse is that sunshine, which as we have seen can generate extremely warm temperatures approaching +100oC, warms the interior surfaces inside the greenhouse because sunlight passes through the glass ceiling and walls. Have you ever been on a hot sandy beach where the sand burns your feet? That is what sunlight can do to surfaces. What happens next, on a beach, is that the air in contact with the hot sand warms up by conduction, then rises, expands, and cools, and cooler air from above comes down and replaces the warm which has displaced it. This process is called convection, and it happens automatically, all the time. But what would happen if you could stop convection?
If you stopped convection, the air in contact with the hot ground wouldn’t rise away, and so that air would just keep increasing in temperature until it matched the temperature of the ground. Given that the ground is heated to high temperature from the sunlight, that means the air will also become very hot. That is the underlying physical principle which governs the behaviour of a real greenhouse. See how that works? See how the underlying physical principle can be identified, manipulated, and engineered? See how it makes sense, is clearly identifiable, describable, and explainable? See how it does what you expect it to, once you’ve identified the boundary conditions? The glass-ceiling allows sunlight to enter but then it stops the warm air, heated by contact with the sunlight-heated surfaces inside the greenhouse, from rising away, expanding, and cooling. The warm air gets trapped, and so it keeps on warming up to the ability of the input sunshine to generate temperature. There is no more heat generation occurring than that which is coming from the input sunshine in the first place, and it is the rigid glass barrier which causes the warm air to be trapped.
A commentator on another thread quoted this description of the GHE he had been given:
“Triatomic molecules (H2O, CO2, NO2, etc.) in the atmosphere absorb the infrared coming up from the planet’s surface and re-emit that radiation in all directions, including back to the surface, thereby preventing that radiation from escaping directly into space. This is what creates the greenhouse effect. It’s very similar to how a blanket keeps you warm on a cold night. The blanket doesn’t create any heat itself – it just keeps heat from escaping.”
This is very similar to the IPCC explanation, and notice the related statement that “radiation prevented from escaping to space is what creates the GHE“. Well, that’s not how a real greenhouse works, which functions by trapping hot air, and so the analogy is that trapping radiation has the same effect as trapping hot air.
This is a very subtle ruse, so we must go through this carefully. When the air gets trapped, it is able to continue heating up to the temperature of the sunlight-heated surfaces it is in contact with. The air gets to a higher temperature than it would have been if it were free to rise and expand. But, does trapped radiation rise to a higher temperature? Does trapping radiation shift its frequency spectrum and make it hotter? No it does not. The radiation from the surface is an output result from the temperature that the surface already has, and so the radiation already corresponds to that temperature. The radiation does not increase in temperature, nor can it create an increase in temperature.
However, here’s the real thing: a real greenhouse also traps radiation, but this trapped radiation has no effect on the temperature inside. There are thousands of real greenhouses in the world. Thousands. We have a lot of greenhouses. It has never been reported, from any of these real greenhouses, that increasing the carbon dioxide concentration inside the greenhouse caused an increase in temperature. Never! And, it has never been understood that the trapped radiation inside a greenhouse contributes in any way to the air temperature inside, but only that the cessation of convective cooling is what changes the temperature inside.
So, the atmospheric greenhouse effect is said to cause heating on the surface by virtue of an (supposed) underlying physical principle, backradiation, by which a real greenhouse does not actually function, even though a real greenhouse also has backradiation. A real greenhouse has backradiation but the backradiation has nothing to do with the heat inside. You’re then tricked into thinking that the trapped hot air inside a real greenhouse is somehow analogous or similar to this non-existent underlying physical principle of backradiation heating.
Is that not an amazing degree of fraudulent subtlety? It is no wonder that so few people are able to see through the lie.
Thus the IPCC totally dismantles the causal chain in a real greenhouse, and then says that the atmospheric greenhouse effect is “analogous but different” to this a-causal and non-existent sequence. The IPCC has completely abandoned the world of rationality and reality and a hyperreal simulacrum has then been shoved between your eyes and the underlying truth.
In regards to the “blanket analogy”, again, a blanket functions by preventing convective cooling, just like a real greenhouse. Blankets have nothing to do with trapping backradiation, and only everything to do with trapping warmed air. The same is true for insulation in a house, etc. Backradiation and blankets or insulation have nothing to do with each other, and this is part of the same ruse as described above. Even so-called space blankets only work by trapping warm air; they’re convenient for backpacking, emergency supplies, etc., because they are a rigid structure that can be folded and stored into an extremely compact space, and because they are extremely light weight. They can outperform a “cloth” blanket because any cloth blanket is permeable to air and so is not 100% efficient at trapping hot air, whereas the space-blanket is totally impermeable to air and doesn’t allow any air exchange through its surface at all.
Note that real blankets and real greenhouses do the opposite thing that the atmosphere actually does, or in other words they stop the atmosphere from doing what it would naturally do, which is have warm air rise, expand, and cool. That is exactly what CO2 does as well, and it does nothing to prevent it because it is part of that process.
Here’s the thing: if there is an underlying physical principle borne out of the laws of reality in which an object can heat itself up some more, to a higher temperature than the input energy creating the heat in the first place, then the principle should be clearly defined and with a direct explanation as to the mechanism, without recourse to non-existent analogies. Further, the principle should be engineerable, and thus exploitable, and concise demonstrations of the function, without confounding analogies and effects from unrelated phenomena (such as hot air trapping), should be made.
You can do work with temperature. That is important. The underlying premise of the AGHE is that backradiation (i.e. self-radiation) makes the surface hotter than the input. If you can make something hotter than the input, you can then get more work output than the input. You can thus see how important and useful such a thing would be if we could identify the functioning principle and thus engineer it. But you also can see that it is a plain violation of thermodynamics. So, if it can be engineered, then please do it! Please, show that it can be done. Be the first person to beat the Laws of Thermodynamics. The world will rejoice at the possibilities unleashed.
Now if other supporters of the AGHE want to say that it only traps heat at night and slows down cooling, well, they’re just inventing a new version of the AGHE which therefore means nothing, and it also destroys the scientific credibility and integrity of the entire premise. We may thus actually state that the scientific credibility and integrity of the AGHE has already been destroyed. The whole atmosphere retains heat at night and greenhouse gases have nothing to do with this fact, and, the real place where heat actually gets trapped and then released at night, keeping things warmer, is in the latent heat of H2O, which has nothing to do with backradiation and the AGHE. Also, the 99% of the atmosphere which is nitrogen and oxygen do not radiate, which means that they are almost 100% efficient at retaining heat overnight. Greenhouse gases, on the other hand, do radiate, and so they are the portion of the atmosphere that actually allows for atmospheric heat loss. This is just another example of the subtle but sophisticated ruse that is the anti-human philosophy centered around the atmospheric greenhouse effect.
See Alan Siddons’ related article on this issue here.