I will go back and have another read. I thought that I had, but obviously not.
So the “conduction and convection” of heat is the main mechanism which debunks the effect of CO2 central role in modern climatology?
And you are claiming that this isn’t being taken into account in climate models?
I read your practical example of a space heater, with the air obviously being forced through heated coils and blowing hot air into the room.
According to your theory, then roof vents would be as effective as the “anticon” silver backed insulation.
They are unequivocally not even in the same ball park.
Blocking the infrared is highly effective, ventilated roof spaces barely make much difference.
I have been asked to install roof vents many many dozens of times because people believe they will prevent the house getting hot.
The effect is extremely mild at best.
“Anticon” silver back insulation, drops the temperature in the roof and all the roof and ceiling members (joists, rafters, etc) so much it’s almost pleasant in the roof space.
So whilst hot air is indeed being created by conduction & convection , and is indeed radiating heat, it all starts with the heat itself.
It’s the source of the heat.
The sun is not directly heating the 99.96%> as oxygen and nitrogen do not absorb infrared. It is heating the CO2 directly. Which, in turn heats via conduction and convection, the air around it.
In your analogy of the space heater, the CO2 is a part of the “electrical heating element”. it’s what is turning sun light (and any other radiating heat) into something which can be conducted to the rest of the air.
Edit; removed my contradiction.
I do appreciate the challenge to look into all of this. I was calculating the molar mass of elements for an hour, before I realised they were already done for me.
To reiterate my view, the whole CO2 politics with is convenient economy, is a massive distraction from the actual destruction of the environment.
It’s a constructed morality, in which people can feel good by being “carbon neutral”.
It does next to nothing to redress the fact that we have destroyed so much of the environment which we evolved in and depend on for our survival. We will probably will try to engineer our way around the problem, yet it remains to be seen if we end up like our science fiction fantasy of Corusant with it’s completely manufactured atmosphere. Harvesting passing comets for elements to create air.
Yeaup… hard to believe. But all the stuff I’ve read so far of how the greenhouse effect works makes this same conflation that the entire effect of heating the atmosphere is due only to the infrared-absorbing elements of the atmosphere, i.e. the radiative heating part, ignoring the conduction & convection part.
The sun doesn’t heat the CO2 directly since the sun’s energy is mostly in the form of visible light, which the CO2 is also transparent to. See this link for example:
Q: Does the Sun ever heat the air, or does it only heat the land, which in turn heats the air?
Paul Harding: […] By the time the Sun’s radiation gets through the stratosphere, all the types of radiation which can heat air have been blocked and filtered out. What’s left is mostly visible light radiation, which zooms right through our part of the atmosphere - the mesosphere - without really interacting with it or heating it up at all. […] Those parts of Sunlight which make it down to us don’t heat the air down here, but they can heat surfaces which visible light doesn’t penetrate, such as the ground and even people.
This answer incidentally also ignores the effect of conduction and convection after said surface is heated:
The surface gets warmed enough to emit lower energy radiation of its own, and that wavelength of radiation can interact with certain substances in the mesosphere, such as water vapor, carbon dioxide, and methane, heating them up.
Presuming for now that you see the sun doesn’t heat the CO2 directly via IR, you would be saying that the surface is heating the CO2 directly via IR, which in turn heats the rest of the atmosphere. i.e. you are making the claim that the entire atmosphere is heated solely due to the CO2 (and other IR-absorbing gases) being heated by infrared (whether it’s from the sun or the surface).
Yet consider that:
1 - Out of conduction, convection, and radiative heating, radiative heating is the least efficient (as empirically demonstrated when designing cooling elements for space stations, see: Cause of Bias? - #196 by claudiu).
2 - The atmosphere is in direct contact with the surface of the Earth, which is hot, therefore it is getting heated by conduction and convection.
3 - 100% of the atmosphere is heated by conduction and convection, while only 0.04% of the atmosphere is heated by radiation.
So, which has the net larger effect of heating the atmosphere?
A - the 100% of it being heated by conduction and convection, the more efficient of the three heat transfer mechansims, or…
B - the 0.04% of it being heated by radiative heat transfer which then heats the rest of it.
This is very interesting. Is the “anticon” silver-backed insulation applies just on the underside of the roof space (i.e. the part facing the house) or also on the topside of it (I guess the part under the roof tiles??)
Also are there any other insulating properties of it, e.g. is it like a puffy not-dense air-filled sponge type of thing coated by a silver layer, or is it just a thin strip of silver?
Also is the issue with the ventilation that it doesn’t actually get ventilated well? e.g. it’s obvious that if the roof space were fully open to the room it would just be the same temperature of the room, due to convection. So perhaps the ventilation isn’t enough due to the physical barrier blocking the convection in the first place, i.e. it’s not enough to reach the same level of convection that would be if there were no barrier betwixt the two.
BTW you get the prize for the first reply actually addressing the argument 
. Congrats and I appreciate it, it makes for a fun discussion.
Yes, well I found myself “taking a side” then realised I didn’t really know much appart from whatever I had picked up over the years.
Regarding the “anticon” there is indeed glass fibre insulation stuck to the top side. There is also a version which is just a foil backed fabric.
The silver foil is only on one side, and it points down towards the ceiling.
Both have a similar effect, although, the glass fibre backed foil also cuts out conduction from the metal roof to the battens.
We generally build with metal roofs in Perth.
It would be fair to say that some of the conduction is being cut out and that is making a difference.
To the question whether the roof space would be the same temperature if it was completely ventilated, I can’t answer from experience, however I have been in lots of clay tile roofs, which because of the thousands of gaps between tiles are the next best thing.(in Perth there is nothing behind the tiles but a timber batten , so you can see light between all of them) and they are extremely hot spaces. You can feel the heat radiating off the back of the clay tiles.
Ventilation makes some difference, but the difference of the foil is night and day.
To the argument that most of the heat isn’t in the light that gets to the lower atmosphere, I challenge that guy to visit Perth in the summer.
There is apparently around 1 kilowatt of solar energy per square meter in summer here.
To quote Robin Williams “It’s hotter than a snakes ass in a wagon rut”
I have spent time to Ghana West Africa, and the difference is amazing. Even in summer time, I can walk down the street there. The amount of moisture and dust and whatever in the air blocks so much heat from getting to the ground.
In Perth, the air is crystal clear and extremely dry.
Which apparently makes it very dense. It doesn’t feel like that though. It feels like being cooked alive.
I will look at the links in your post now.
This is a quora answer though, is there a better source? He is deputy sheriff or something.
Hmm, I don’t physically experience what you are putting forth.
In summer, in the morning, the air here is usually pretty still. The whole city awaits what we call the “Freo Doctor” which is a south westerly wind that comes from the ocean around 2-3 pm.
In the morning all of the heat is purely the sun.
Talking about how much heat the sun puts out, it’s instantaneous here. As soon as you can see it, it’s hot.
Last summer, I was on the balcony with my then girlfriend. I always wake up early, so I made her get up and watch the sun rise with me.
The very instant it was visible, the heat was straight in our faces. That’s at around 5:15 am. I mentioned that because we were high up, so there was nothing blocking the sun, which is normally filtered a bit at my place with trees.
I am awake most early most mornings, and that heat is instantly there when it rises.
So, I really am not sure what that guy means when he says the sun heats the upper atmosphere, and only “visible” light is left.
It’s like opening an oven and putting your face in it. That’s at 5:15am.
OK, that is the standard accepted understanding behind the climate change model though – that the atmosphere is transparent to the visible light of the sun (ie the sun doesn’t heat it up) but opaque to the infrared light the surface emits, and its therefore heated up by said infrared light from the surface.
e.g. from this link: “When energy from the Sun reaches the top of our atmosphere, most of it passes through to Earth’s surface, where it is absorbed.”
I don’t disagree with this aspect, it seems to make sense.
Yeah, when the sunlight hits your face and you feel the heat instantly, you are feeling the heat of the sun directly. The suns rays do heat your face directly, like they do the ground. The point is that they don’t heat the air. It’s visible light and the air just lets that light through without interacting with it.
Be that as it is, efficiency isn’t what this is about. To the point of conduction and convection, I am interested in your first statement;
Indeed, I do find this hard to believe.
Obviously , if it is true that the climate models are ignoring this, then it would be a huge mistake.
Though, I still don’t see how this counters the heat getting there in the first place.
I can only keep talking about my experience of heat.
It’s unconvincing that conduction and convection no matter how efficient, are responsible for how hot it gets here. I have also spent a fair amount of time (a few months in total) on the Nullarbor plain, and also central western Australia. (The second biggest dry desert in the world). The heat is unbearable. It is there instantly.
It goes from over 40 C to 1-2 C at night out there (no ocean to keep the temperature more stable).
In Perth, it can, because of the “heat sink” effect and the occasional easterly wind, it can still be 30 C in the middle of the night.
Walking around, one feels the heat radiating off everything. The walls, the ground. Long after the sun is gone.
So definitely radiation, conduction and convection going on, but it all got there from the sun.
But anyway, the point you are making about the science ignoring the conduction and convection would be globally a huge mistake. It’s not all Perth after all.
I will have a bit more of a search through your other posts for links.
Ok, now I am getting the argument here. So the sun heats the ground, not the air.
However, what did you make of that YouTube clip?
It clearly demonstrates the blocking effect of CO2.
To get back to the point I was making, then it’s even worse that they are making CO2 the main player, because it would precisely be more trees and healthy ecosystems which would deal with the heating up of the ground.
I have definitely seen papers in the past that touch on the subjects of conduction and convection, moreso convection because of its applicability to gases and water vapour (also considered a greenhouse gas). Most gases in the atmosphere have low thermal conductivity. There are known gaps in needing to better understand how the condensed states of water impacts the absorption and emission of radiation too. So, clearly the models are something still with gaps and evolving.
There are aspects to consider, for example heat by radiation doesn’t require a medium or proximity that conduction and convection do. Then depending on the molecular structure of the gas there are differences for convection and radiation, so the degrees of freedom and the ability for specific molecules to absorb and re-emit certain frequencies of electromagnetic radiation have to be considered.
From what I am aware I don’t believe there is any evidence of convection or conduction in the atmosphere reaching a sufficient level to excite different electron states in these gases so as to then emit photons, though I could be wrong on this.
Yes, well this being that the model that the radiation from greenhouse gases occuring pre the industrial revolution have always contributed to the Earths surface having a warmer temperature than expected. In the same way that Venus is hotter than Mercury due to the constituents of its atmosphere, despite Mercury being closer to the sun.
I have always been super sceptical about everything and never take any scientific hypothesis, theory or model as absolute. I think it is a complex area that I am sure will have more information to come to light to understand what is happening.
To me, I sometimes find it is useful to ask the question what has led them to this pathway to make such a hypothesis, i.e. of blaming these particular greenhouse gases. Then the important question is why are they trying to form this argument that these trace levels of gases can cause such vast temperature differences?
If we avoid the overloaded sort of apocalyptic meanings that come with global warming and climate change and just consider the terms as descriptors for evidence that human involvement has changed the climate then there are several other forms of evidence to indicate that human involvement has changed things and for wanting to try and understand why and how this is so.
It is clear that the surface temperature of the Earth has been increasing. I am pretty sure that you are not in disagreement with this. The temperature has increased since the industrial revolution and especially so since the mid 20th century. The problem is there has been no other model that has been able to accurately describe why this is happening.
We know enough about the orbit of the Earth and it’s rotation (including irregular wobbles) and the output of energy from the Sun to the Earth, to understand how this affects temperature and energy on the Earth’s surface. Well this energy level doesn’t adequately compensate and explain the increase of the surface temperature.
We understand now the general Total Solar Irradiance from the Sun, the energy it outputs to the Earth, measurements taken from the NASA satellite TSIS-1 for example. Considering the measurement precision, error and accuracy of the satellites used in taking this measurement, this still doesn’t explain the temperature increase either.
Even understanding the 11 year cycles the Sun comes under and other significant phenomena such as flares and solar storms that have happened, all of these can’t explain why the temperature has increased to this level we have seen.
We do know from ice cores that the quantity of CO2 and Methane are recorded and rates indicate the levels are now higher than any other time previously. These gases absorb infrared differently based on their molecular structures.
The radiative flux (Radiative flux - Wikipedia) has been measured for the different greenhouse gases via Infrared spectroscopy and gives an indication of the downward radiation power/energy over a given area for each type of greenhouse gas including other pollutants that have cooling effects. These being measured in different seasons and locations over the year. These then contribute to additional internal energy within the Earth.
I am not sure that is correct, I believe in this case the issue is the low emissivity of aluminium used as the material for the radiators and whatever other coatings and treatment is has. But aluminium responds well to changes in heat hence why we use it in radiators here on Earth too.
I think it is not the case that conduction and convection doesn’t add heat to the system but that those phenomena alone can’t explain the increased energy in the system (Earth, its surface, atmosphere and then nearby space being the system).
So, the premise of climate change put forth by the science community is in question. You were clear with that, I just didn’t catch on to the air not being directly heated up bit.
This though doesn’t actually get humans off the hook as far as climate change goes through.
It actually makes it worse.
If conduction and convection are the main drivers of atmospheric warmth, then the huge expanses of farmland where once there was forest need to be replanted with as many trees as possible.
Some huge percentage of the worlds forests ( I want to say 60%) are now farms.
On the topic of CO2 being a convenient political, economic and moral diversion;
I am a building estimator (quantity surveyor without the degree). In the last 2 years I have seen the price of timber more than double. This was a global shortage which revealed the scam that so many governments have been involved in regarding “carbon offsets”. They have been using plantation timber as a “offset” because it’s used in buildings and counts as carbon storage. Yet, they haven’t been planting anywhere near enough for demand. The Western Australian government was one of the worst. For 15 years, they didn’t restock the plantations, even went as far as privatising them, whilst at the same time using what plantations they had as “carbon offsets” in the high profile talks around the world. They weren’t the only ones either.
So they basically ignored anything to do with planting anything because politically, CO2 was the hot topic.
In testament to just how blindly the general populace is to this manipulating, I have not seen a single report or media “exposure” over the whole thing.
Infact, the WA government went as far as to publicize it was releasing “5000 tons” of reserve plantations to alleviate some of the local shortfall.
The very one’s who didn’t plant anything for 15 years, privatised it, still managed to get political points out of it.
Oh, and no new trees got planted until last year. At private expense. Instead, we imported Baltic pine from Europe.
Yea but the basis of the models is all that the IR-absorptive gases are 100% responsible for the reason the surface is around 15C instead of around -18C. If this premise is flawed then the models are just totally wrong, and filling the gaps in them won’t rescue them.
From what I understood from the answer (link), it doesn’t much matter whether a gas is heated by conduction/convection or radiation (+/- effects specific to the gas like O2 forming O3). The effect either way is a warm gas. The warm gas then radiates out its heat the same regardless how it got warm.
I don’t think its the specifics to the space station. From the reddit thread again:
Tridgeon: The radiator on your gaming computer mainly uses convection to dump waste heat into the air by forcing it past the metal plates on the radiator using a (often led bedazzled) fan. Space is a vaccum and so there is no air to force past the radiators, the ISS looses heat by radiating it away as photons. This is much less efficient and needs much more surface area than a similar capacity radiator on Earth but doesn’t require any fans.
Also see this link for example:
Heat can be transferred in one of three ways: conduction, convection, and radiation.
The most efficient method is conduction […] A slower method of heat transfer is convection […] The least efficient method of heat transfer is radiation.
Also consider the moon gets to 120-130C during its day. I believe that that’s because, it having no atmosphere, it can only lose heat via radiation – and so the thermal balance is reached only when the ground heats up to 120C, even though its receiving the same amount of solar energy per sq meter as the Earth is.
(EDIT: ah the far longer lunar day will obviously have an effect on that too!!)
One thing I’m unclear on is how one would tell the difference between IR radiated by the air just because it’s hot and within the temperature that any object emits IR, vs. specific emission from CO2. I’m working on a question I’ll ask on that physics forum to see. Cause if they’re just measuring IR due to the heat of the air itself anyway… then that will really conflate these measures (accounting the IR of the entire air itself as due entirely to the IR of the CO2). Fun to learn about such things!
As to the rest I will have to ponder upon it and reply in fuller later!
This bit about trees being cut down has the same correlation to temperature increase in terms of time as the increase in CO2
@claudiu Now you have me wandering around looking at the sky even more! Thinking about how to design some inexpensive experiments.
I always find that I have more questions than I do answers and can quickly spiral into an infinite loop of never ending questioning lol.
Yes, I am aware. There is a piece missing, the value for this surface temperature that is below expectations is established from the concept of Power (in) = Power (out) for the energy received from the Sun.
So, Power (in) from the Sun is derived from Power = Intensity x Area, but it gets modified to compensate for reflection i.e. albedo which is negative to take away the lost energy. This is taken as 0.3.
Power (out) from the Earth is then estimated utilising the Stefan-Boltzmann law to represent the Power emitted from a particular body, this case the Earths surface.
They consider emissivity of Earth to be approximately 0.9. This value is described below in Wikipedia.
Earth’s surface emissivities (εs) have been inferred with satellite-based instruments by directly observing surface thermal emissions at nadir through a less obstructed atmospheric window spanning 8-13 μm.[26] Values range about εs=0.65-0.99, with lowest values typically limited to the most barren desert areas. Emissivities of most surface regions are above 0.9 due to the dominant influence of water; including oceans, land vegetation, and snow/ice. Globally averaged estimates for the hemispheric emissivity of Earth’s surface are in the vicinity of εs=0.95.[27]
The overall equation then is defined as below.
Which then can be re-arranged to get the surface temperature:
Plugging in the different constants, the radius of the Earth and the Intensity value for the Sun’s Power at approx 1370 Watts per square meter you then get a temperature of 255K which is approx –18C.
Therefore, it is these relationships and models that are the reason the temperature is estimate at -18C. The infrared model both from normal levels of greenhouse gases (and now abnormal due to anthropogenic causes) is an attempt to explain why the Earth’s temperature is actually greater than this value.
This is what I was alluding to though, that radiation is different because it can induce an excited state of the gas, not only because it doesn’t require a medium but also because the emission when dropping from an excited state to a ground state can emit radiation and that can be subsequently re-absorbed by another molecule. So, when that particular frequency is in the infrared range than it happens to be of a type that can maintain more energy to the system.
What I mean is, is that it requires a greater surface area of the radiators to compensate for the surface emissivity being low of the material they have used for it, I think it was aluminium where I read somewhere else. This link, I like the surface emissivity explanation: (Surface Emissivity -- Why It Matters In Insulation — Sigma Technologies)
Surface emissivity is the amount of infrared energy emitted by a specific material. It is often expressed as a ratio or percentage of “1” with the “1.0” value being perfect “black body”. A material that emitted heat energy at half that rate, like polyester film, would have a rating of .50 or 50%. Objects like aluminum or copper, with low surface emissivity (low-e) do not transmit heat well because most of the infrared energy is reflected instead of absorbed.
So, are we talking about the materials inefficiency to emit infrared because it has low emissivity or are we talking about infrared as being an inefficient means of transferring heat in comparison to the other modes?
Additionally, I was confusing myself regarding the speed of transfer for each mode of heat transfer with efficiency, speed for radiation is superior to the other methods.
Though efficiency has me thinking are we talking in terms of the materials used, energy cost, or just outright the most efficient based on: per unit of power output by per unit of power input?
For example, that link you sent, an insulator company will compare based on those metrics that have most relevance to the cost of the project so they are probably considering both the material cost and cost of energy to the customer for the amount of heat they get. So its all about efficiency in the sense of what it means to the end customer.
I am pretty sure though efficiency will have different relevance in different situations. For example, radiation wins in space lol. (https://qr.ae/prVggn)
I started thinking about the Moon too. The lack of atmosphere makes it easier for it to lose the heat from the surface too, hence the then extreme cold when at its night. Again, see the equation above and the models considered for the temperature of the surface of the Earth. I always try to think what could be lacking and missing from the assumptions. I wonder if the model predicts accurate values for the moons surface, then I found something lol.
You can see that same calculation for an example of the Moon here (Temperature on Moon With Sun Overhead, Blackbody Equation - YouTube).
It seems they focus on the spectral emission of the particular gas under infrared, but there are differences from small, medium to longwave infrared. The spectral lines vary under different pressure conditions too.
They get the change in this radiative flux over particular wavelengths and they integrate this to get the radiative forcing (is the change in energy flux in the atmosphere caused by natural or anthropogenic factors of climate change as measured by watts / meter²).
This article I found helpful regarding the example of CO2 (The CO2 GHE demystified | Clive Best). They had another useful article regarding concentration implications on radiative forcing as well (Radiative Forcing of CO2 | Clive Best).
There seem to be a lot of modelling complications such as spectral overlapping, absorption saturation and they make adding up the radiative forcing not just a simple summing up of values. There are interference effects from water vapour. Then you have water vapour and ozone with shorter lifespans and highly variable concentrations not always included in the calculations either.
An article saying that climatology absolutely does not ignore convection.
This site is a goldmine,
Really good explanation of “heat transfer” vs “energy transfer”.
The effects of insulation, etc.
That in the end, radiation is the only way that heat energy ends up back in space and the “lapse rate” being the temperature drop in atmospheric gasses as altitude rises.
In short, the more resistance the atmosphere has the higher the average altitude that radiation is transferred back into space, resulting in increases the surface temperature.
I am going to check I understood that correctly though…