[alancalverd (OP)]

Even if CO2 were a plausible driver of historic temperature, we still need to find a reason why its concentration varied in the way it did.

Historical causes of warming are beside the point, what humans are doing is a unique situation.

Unique but probably irrelevant. As the CO2 absorption bands are saturated and the climate over the last 50,000 years has followed the same pattern as 100,000 years previously and several times before that, it seems logical to begin with the premise that the laws of physics haven't changed, so whatever precipitated the rise in temperature (and thus the rise in CO2) in the past, is still functioning.  All we have done is to add a bit of CO2 to an already saturated spectrum.

[Petrochemicals]

I have just been informed by the telescreen that half of global warming is atributable to methane, this mainly coming from fossil fuels,this would of course tally with the cool records, the switch from good old fashioned hydrogen  and increased drilling/population

[chiralSPO]

Even if CO2 were a plausible driver of historic temperature, we still need to find a reason why its concentration varied in the way it did.

Historical causes of warming are beside the point, what humans are doing is a unique situation.

Unique but probably irrelevant. As the CO2 absorption bands are saturated and the climate over the last 50,000 years has followed the same pattern as 100,000 years previously and several times before that, it seems logical to begin with the premise that the laws of physics haven't changed, so whatever precipitated the rise in temperature (and thus the rise in CO2) in the past, is still functioning.  All we have done is to add a bit of CO2 to an already saturated spectrum.

Can you read?
All of these points have been thoroughly debunked in previous posts within this thread (by me in reply #4, quoted again for your convenience in reply #12, since you apparently didn't read it then, and again below just for you, and #27)

Now either all the published papers on CO2 absorption are wrong or plagiarised from two flawed sources, or the hypothesis that increasing p[CO2] will increase surface temperature is nonsense.

The atmosphere absorbs effectively 100% of the radiation at these wavelengths (if you're looking down the whole length of the atmosphere), but the % absorbance or % transmittance or however you choose take your IR spectrum has very little bearing on the greenhouse effect (it's mechanism, magnitude or cause).

Even if the atmosphere is treated as 100% opaque to the wavelengths absorbed by CO₂, it is straightforward to see that changing the concentration of CO₂ will still change the mean free path of the photons that are interacting with CO₂.

We can think of a photon emitted from the ground and needing to reach "space". It will start out going straight until it runs into a CO₂ molecule and gets absorbed, hangs out for a time before being re-emitted in a random direction until it bumps into the next CO₂ molecule or escapes to space. Essentially it have to take a random walk from the surface to some altitude sufficiently high. And the time it takes has nothing to do with the speed of light (we can assume it is c for this), but rather in how many stops it has to take (each one being a significant delay compared to whizzing by at c), and how much time is being spent traveling the "correct" way.

The higher the CO₂ concentration, the shorter the mean free path of the photons.
The shorter the mean free path of the photons, the more hops need to be taken to escape (exponentially so!)
The more hops needed to escape the slower the rate of energy transfer through the atmosphere.

Or, if you would prefer: by Bored chemist in replies #9, #14, and especially #24 , again, I'll quote it below, just for you, so it's easier to find)

Now either all the published papers on CO2 absorption are wrong or plagiarised from two flawed sources, or the hypothesis that increasing p[CO2] will increase surface temperature is nonsense.

The atmosphere absorbs effectively 100% of the radiation at these wavelengths (if you're looking down the whole length of the atmosphere), but the % absorbance or % transmittance or however you choose take your IR spectrum has very little bearing on the greenhouse effect (it's mechanism, magnitude or cause).

Even if the atmosphere is treated as 100% opaque to the wavelengths absorbed by CO₂, it is straightforward to see that changing the concentration of CO₂ will still change the mean free path of the photons that are interacting with CO₂.

We can think of a photon emitted from the ground and needing to reach "space". It will start out going straight until it runs into a CO₂ molecule and gets absorbed, hangs out for a time before being re-emitted in a random direction until it bumps into the next CO₂ molecule or escapes to space. Essentially it have to take a random walk from the surface to some altitude sufficiently high. And the time it takes has nothing to do with the speed of light (we can assume it is c for this), but rather in how many stops it has to take (each one being a significant delay compared to whizzing by at c), and how much time is being spent traveling the "correct" way.

The higher the CO₂ concentration, the shorter the mean free path of the photons.
The shorter the mean free path of the photons, the more hops need to be taken to escape (exponentially so!)
The more hops needed to escape the slower the rate of energy transfer through the atmosphere.

"

Evidence is one thing,

And what you presented is another; at least  in regard to what you said.
You actually said  this

water is indeed the problem, and as the ice core data shows, always has been.

The ice core record (ironically) does not tell you about water levels in the air.

If you really think it does then please give us a link.

I cannot find a rational interpretation consistent with CO2 being the driver of historic climate change.

Good point- sort of.
But inevitable and meaningless.

It is true that the historical record does not show CO2 leading a temperature rise.
But that's because, prior to mankind getting in on the act, there was no plausible source of CO2 that could materially affect the concentration in the atmosphere.

You will not see, at any point in Earth's history a record of what happened when mankind suddenly raised CO2 levels roughly 10 times faster than they have every risen before.
Because mankind never did it before.

That's more or less the point of anthropogenic climate change. Nobody ever did it before.
So it makes no real sense to look at the historical record for a precedent for "today's" events - say the last 200 years.
Historical climate change was not driven by anthropogenic CO2.

Nobody said it was.


But here's the actual explanation of the link between CO2 and climate.
TLDR version, it's not been the cause in the past; it has been an amplifier- a positive feedback mechanism  enhancing changes due to orbital effects.

But it still has the effect of creating warming, even if the initial source isn't orbital variation, but mankind.

[Bored chemist]

Unique but probably irrelevant.

No.
It's probably not irrelevant.

As the CO2 absorption bands are saturated

\The grown ups explained why
(1) this is not true
(2) why it would  not be relevant, even if it was.

the climate over the last 50,000 years has followed the same pattern as 100,000 years previously

No It has not, we currently have the fastest rising levels of CO2 ever.
It's not "the same pattern".

, it seems logical to begin with the premise that the laws of physics haven't changed

Yes.
Those laws say that CO2 is a greenhouse gas and will cause the world to warm up.

Why do you keep ignoring them?

All we have done is to add a bit of CO2 to an already saturated spectrum.

Why do you keep telling that lie?

[chiralSPO]

Improbable, and unpopular. Most people think the laws of physics haven't changed since a few milliseconds after the Big Bang.

Anyway, rather than argue the toss, I want to measure the intensity of outgoing 15 μm radiation as a function of altitude at night. Can anyone direct me to a suitable commercially available detector? Most of those advertised seem to cut off at 14 μm! 

like this? https://www.excelitas.com/product/pys-3198-single-channel-pyrodetector

[Bored chemist]

the switch from good old fashioned hydrogen 

We never used "old fashioned hydrogen".
We did use coal gas which is about 50% hydrogen, but it's also about 30% methane.

I have just been informed by the telescreen that half of global warming is atributable to methane

As ChiralSPO pointed out, that comparison is meaningless unless you include a time scale.

[chiralSPO]

I have just been informed by the telescreen that half of global warming is atributable to methane, this mainly coming from fossil fuels,this would of course tally with the cool records, the switch from good old fashioned hydrogen  and increased drilling/population

Methane is a significant factor in global warming (and is getting worse, though I'm not sure it's up to 50% just yet...), and is nearly entirely attributable to:
• oil and gas exploration/extraction
• livestock
• decomposing organic waste (garbage heaps)
• and more recently, outgassing of permafrost and clathrates. (this is how climate change will get us—if we warm up enough to significantly thaw the permafrost in Siberia and Canada, methane may well become the dominant driver (for a time).

[Bored chemist]

Anyway, rather than argue the toss, I want to measure the intensity of outgoing 15 μm radiation as a function of altitude at night. Can anyone direct me to a suitable commercially available detector? Most of those advertised seem to cut off at 14 μm!

Good luck.

It's a bit like measuring water at the bottom of the ocean.

Everything (including your detector), unless it is very well cooled, will be emitting radiation in that range.

Did it occur to you that there might be a reason that the market was a bit thin?
It's perfectly possible to measure in the mid IR, but it isn't trivial.
You may recall the spectrum posted here earlier.
https://www.thenakedscientists.com/forum/index.php?topic=83465.msg659000#msg659000
This is the relevant bit


15 micron.JPG (12.33 kB . 189x590 - viewed 1131 times)

That spike on it is the signal you are looking for; the one you keep trying to say is saturated.
The slope is the detector response failing because everything lights up at those wavelengths while the sensor response drops.

[Bored chemist]

Why is this graph not flat? Or at least linear? Does the sun do a particularly good job in issuing IR around the peak?

The graph has nothing to do with the sun.

[Petrochemicals]

I have just been informed by the telescreen that half of global warming is atributable to methane, this mainly coming from fossil fuels,this would of course tally with the cool records, the switch from good old fashioned hydrogen  and increased drilling/population

Methane is a significant factor in global warming (and is getting worse, though I'm not sure it's up to 50% just yet...), and is nearly entirely attributable to:
• oil and gas exploration/extraction
• livestock
• decomposing organic waste (garbage heaps)
• and more recently, outgassing of permafrost and clathrates. (this is how climate change will get us—if we warm up enough to significantly thaw the permafrost in Siberia and Canada, methane may well become the dominant driver (for a time).

So of that oil and gas and outgassing from bogs is new. Plus the fact that methane from oil and gas industries is historically under reported.

[Bored chemist]

So of that oil and gas and outgassing from bogs is new.

No.
So called "Marsh gas" - one of the earliest known forms of methane is not new- obviously.

[alancalverd (OP)]

Even more fun: huge deposits of prehistoric methane clathrates are predicted to outgas as the permafrost retreats. 

[Kryptid]

I may move it over to New Theories or That CAN'T Be True if it continues to devolve.

I would recommend doing that anyway.

[mikewonders]

In that case there must be more more than co2 responsible for the vast majority of heat retention.

Not really.

Is water vapor a greenhouse gas? (yes, substancially)
Is water vapor also a force amplifier of CO2 greenhouse effect? (absolutely)
Does an increasing troposphere and increasing temperatures increase water vapor impact? (yes)

What is the formula for water vapor from octane combustion?

• (Fuel + O2 → CO2 + H2O)
• Gasoline - 2C8H18 + 25O2 → 16CO2 + 18H2O

One mole of octane is equal to 114 grams so one gallon of gasoline (or octane equivalent) is equal to 24.164 moles of octane.
Roughly speaking, one gallon of gasoline (or octane equivalent) will produce just over one gallon of H2O.
The majority of the hydrogen is from ancient stored hydrocarbon from captive form "below" ground.
The oxygen is atmospheric mostly.
The result is the formation of NEW water by volume above ground (as vapor).
How many Quintilian and more gallons of NEW water has been evolved ~ 60+ post modern years?

The consequences are fairly clear on the simplest of evaluations and only gets worse as we apply deeper modeling to quantify it.  The rise in ocean levels, volume and surface area cannot be accounted for simply by glacial melt, less precipitation re-deposition cycles.

How does the ocean surface area and volume affect evaporation in rising temperatures?
(Heat sync, dark field absorption, evaporative cooling)

Reducing fossil fuel combustion carbon emissions from the atmosphere is a no-brainer from even the most basic sense of sustainability.  However, failing to accurately account for the total impact and outcome of a century of increased water vapor and rising oceans with rising temperatures among all the methane releases (CH4) touted today as "clean energy" is a formula for disaster.

Not only has the troposphere increased in altitude (~ 11 kilometers average) but ignoring the effects of increased water vapor aloft facing vortex distribution to the poles, exposes a 4th or quantum state of water at freezing temperatures which can and does destroy Ozone very effectively.

Good luck replacing on-demand combustion energy with wind / solar beyond 30% with variable reliability not to mention numerous new waste streams outside of controls, depleting finite resources, copper, lithium, other rare.

The solution is to utilize combustion resources from above ground (neutral equilibrium) while replacing the loss of resource in sustainable balance plus.  The energy production needs to include CHP heat to energy production to reduce IR contribution while converting water vapor to liquid and splitting that back to atmospheric values, tapping the Hydrogen (clean energy source) and emitting the oxygen back to atmosphere.

CO2 is convenient to point a finger at.  The problem is reduction of CO2 will not meet the temporal demands in time relative to model predictions because the effects of growing water vapor / oceanic feedback is not built into the models in most cases, and certainly not accurately where it is considered.

There are many other contributing factors not being accounted for relative to population and population increases projected, especially in the form of IR thermal emission / Kwh per body globally when we identify the TOTAL wattage production on a realistic scale, growing as it is with increasing use of energy attending post-modern progress. Humans use an enormous amount of energy today, nearly all of it having a thermal emission value.

So yes, there IS more to it than just CO2, by a long shot and unfortunately we're basically still off task in understanding it correctly, thus the current initiatives are even more off task at reaching the desired outcome in the time frames projected.

We want to err on the side of caution and not dismiss things out of hand easily.

[Bored chemist]

The result is the formation of NEW water by volume above ground (as vapor).

Until it rains.

[mikewonders]

The result is the formation of NEW water by volume above ground (as vapor).

Until it rains.

[...] which occurs at increasingly higher concentrations as more new water emerges, hence regional flooding versus drought patterns become more severe and more persistent, growing among the effects that form those patterns.

When, where and how much it rains is the more critical aspect.  Increased tropospheric volume means greater water vapor (and greenhouse density) remains aloft AND greater precipitation also occurs increasing ocean volume, but so does water distribution above the troposphere, so not so much "Until it rains" but the relative conditions of changes in rain increasing with climate impact.

Unfortunately above the level of cloud formation dropping temperatures into the tropopause we don't get rain.  We get hydroxly conversions on the way and fourth state liquid water crystals increasingly impacting polar conditions and Ozone depletion, which means water vapor above the level forming rain is increasing as well, but may also increase in losses outside the atmosphere to space partly.  Probably not where we want oxygen depletion to increase at any rate.

The larger portion of growing precipitation occurs over the oceans, again adding to that growing volume of new water ever more to the rising oceans, along with glacial contribution and increased risk of methane release both oceanic retention losses as well as increasing ancient permafrost losses, enriching CH4 to the atmosphere outside the normal Methane cycle equilibrium.  Methane is a far more potent greenhouse gas and again subject to amplification by the increasing water vapor volume / depth / density (gradients of relative humidity).  This is why we're late in the game to trust only on CO2 mitigation, because other parts of critical cycles are now further contributing risk factors increasing.

Remove the fossil fuel resource sustainably, then reduce the overall water volume gradually, and you end up back to equilibrium much more quickly than hoping to reduce CO2 alone in the given state of acceleration we're now in. 

Precipitation increases globally have tracked even more closely to temperature rise than CO2 does.

"Water" is such a fully incorporated part of our lives and experience, its hard to wrap one's head around it contributing as an enemy when we see it, experience all the time and depend on it.  We experience the change in a gradual manner over our life time even though the changes caused by fossil fuel combustion have accelerated in the wink of an eye in the larger scheme relative to many centuries.

The earth has experienced periods of much higher levels of CO2 (as much as double current levels) over a much more gradual span in past millennia.  The problem we face today is the current rate of temperature change and the very long time it takes for the earth to respond back to a more tolerable balance are not favorable as our thermal emissions footprint will remain elevated.  We can reduce CO2 almost overnight if we really chose to (hypothetically speaking).  The imbalance in climate without reducing the over-abundance of IR emission and water volume feeding the amplified thermal loops may well take centuries to respond.  During the pandemic, CO2 emissions dropped substantially.  Temperature remained within the mean variations despite the CO2 improvement.

[Bored chemist]

When, where and how much it rains is the more critical aspect.

Good point.
We have added an additional 100 ppm of CO2 to the atmosphere.
If we make the most pessimistic assumption then that was all from natural gas and each molecule of carbon was accompanied by 2 molecules of water.
(In reality, much was from coal where very little water is added and much of it was from oil where there's about 1 molecule of added water for each molecule of carbon dioxide.)
So, we cant have added more than 200 ppm of water to the air (and, in reality of course, most of it fell out within days but let's ignore reality, and assume it's all still there in the atmosphere).

The air in the UK is typically about 75% RH
The average temperature is about 10C
This page
https://www.engineeringtoolbox.com/water-vapor-air-d_854.html
tells me that's equivalent to about 0.0054 kg of water per kg of air.
  1 Kg of air is about 34.5 moles
0.0054 kg of water is about about 0.3 moles of water
So the air is about 1,000,000 * 0.3/34.5 i.e.  8696 ppm of water (around here - there's much more in the tropics and rather less in the polar regions).

So we might have changed it by 100/8696 i.e. about 1% (except, of course, most of that water fell straight out of the sky)
whereas we have actually changed the CO2 by about 33%

So, yes, you are right, it's important to focus on the amount of water we have added, and which contributes to rain.
We considered it, and it's tiny.

Here's another way to look at it.
According to wiki
https://en.wikipedia.org/wiki/Earth_rainfall_climatology
"Approximately 505,000 cubic kilometres of water falls as precipitation each year".
That's 5.05e+14 tons
And CO2 production is about 40 billion tons
That will be accompanies by roughly the same mass of water- as you say.
 

Roughly speaking, one gallon of gasoline (or octane equivalent) will produce just over one gallon of H2O.

So that's (to make the arithmetic easy) about 50 billion (5.0e+10) tonnes of water produced by burning fossil fuel.

So we added about 1 part in 10,000 to the rainfall.
Do you think we would notice that change?

[Origin]

The rise in ocean levels, volume and surface area cannot be accounted for simply by glacial melt, less precipitation re-deposition cycles.

True, about 1/3 of the rise in the ocean level is due to the increase in the ocean temperature.

[Petrochemicals]

How many Quintilian and more gallons of NEW water has been evolved ~ 60+ post modern years?

Coal is mostly carbon, so it produces no water, unlike  the hydrocarbon oil and gas. But if we say 300 x10 (9) tonnes of oil and gas have been burned that produce twice as many water molecules as carbon molecules. Averaging 3300 kg co 2  per tonne of hydrocarbons , atomic weight 12+8+8 =28, h20 must be (1+1+8=10)x2 2000 kg of water per tonne of fuel ? So 300x10 (9)x 2000 means a net increace of 6000000000 cubic metres of water.

More significantly the burning of fossil fuels creates hot air and movement, further increacing evaporation. In some industrial cases cooling is facilitated by evaporation meaning massive evaporation is taking place.

[Bored chemist]

means a net increace of 6000000000 cubic metres of water.

And
The volume of water in all the oceans together is approximately 1.335 billion cubic kilometers
or 1.335e+18 cubic metres.
So the amount we have moved about a bit by burning fossil fuels is 1 in 222,500,000 of the total.

More significantly the burning of fossil fuels creates hot air and movement,

You mean "less insignificantly".
Just compare the total energy we set free by burning fossil fuel, and the amount the earth gets from the Sun.
https://www.thenakedscientists.com/forum/index.php?topic=71332.msg532820;topicseen#msg532820