E.M. Smith provides an helpful critique of a recent incomplete theory of earth’s climate functioning in his Chiefio blog post So Close–Missing Convection and Homeostasis. Excerpts in italics with my bolds and added images.
It is Soooo easy to get things just a little bit off and miss reality. Especially in complex systems and even more so when folks raking in $Millions are interested in misleading for profit. Sigh.
Sabine Hosenfelder does a wonderful series of videos ‘explaining’ all sorts of interesting things in and about actual science and how the universe works. She is quite smart and generally “knows her stuff”. But… It looks like she has gotten trapped into the Radiative Model of Globull Warming.
The whole mythology of Global Warming depends on having you NOT think about anything but radiative processes and physics. To trap you into the Radiative Model. But the Earth is more complex than that. Much more complex. Then there’s the fact that you DO have some essential Radiative Physics to deal with, so the bait is there. However…
It is absolutely essential to pay attention to convection in the lower atmosphere
and to the “feedback loops” or homeostasis in the system.
The system acts to restore its original state. There is NO “runaway greenhouse” or we would have never evolved into being since the early earth had astoundingly high levels of CO2 and we would have baked to death before getting out of our slime beds as microbes.
OK, I’ll show you her video. It is quite good even with the “swing and a miss” at the end. She does 3 levels of The Greenhouse Gas Mythology so you can see the process evolving from grammar school to high school to college level of mythology. But then she doesn’t quite make it to Post-Doc Reality.
Where’s she wrong? (Well, not really wrong, but lacking…)
I see 2 major issues. First off, she talks about the “lower atmosphere warming”. Well, yes and no. It doesn’t “warm” in the sense of getting hotter, but it does speed up convection to move the added heat flow.
In English “heating” has 2 different meanings. Increasing temperature.
Increasing heat flow at a temperature.
We see this in “warm up the TV dinner in the microwave” meaning to heat it up from frozen to edible; and in the part where the frozen dinner is defrosting at a constant temperature as it absorbs heat but turns it into the heat of fusion of water. So you can “warm it up” by melting at a constant temperature of frozen water (but adding a LOT of thermal energy – “heat”) then later as increasing temperature once the ice is melted. It is very important to keep in mind that there are 2 kinds of “heating”. NOT just “increasing temperature”.
In the lower atmosphere, the CO2 window / Infrared Window is already firmly slammed shut. Sabine “gets that”. Yay! One BIG point for her! No amount of “greenhouse gas” is going to shut that IR window any more. As she points out, you get about 20 meters of transmission and then it is back to molecular vibrations (aka “heat”).
So what’s an atmosphere to do? It has heat to move! Well, it convects. It evaporates water.
Those 2 things dominate by orders of magnitude any sort of Radiative Model Physics. Yes, you have radiation of light bringing energy in, but then it goes into the ocean and into the dirt and the plants and even warms your skin on a sunny day. And it sits there. It does NOT re-radiate to any significant degree. Once “warmed” by absorption, heat trying to leave as IR hits a slammed shut window.
So what does happen? Look around, what do you see? Clouds. Rain. Snow. (sleet hail fog etc. etc.)
Our planet is a Water Planet. It moves that energy (vibrations of atoms, NOT radiation) by having water evaporate into the atmosphere. (Yes, there are a few very dry deserts where you get some radiative effects and can get quite cold at night via radiation through very dry air, but our planet is 70% or so oceans, so those areas are minor side bars on the dominant processes). This water vapor makes the IR window even more closed (less distance to absorption). It isn’t CO2 that matters, it is the global water vapor.
What happens next?
Well, water holds a LOT of heat (vibration of atoms and NOT “temperature”) as the heat of vaporization. About 540 calories per gram (compared to 80 for melting “heat of fusion” and 1 for specific heat of a gram of water). Compare those numbers again. 1 for a gram of water. 80 for melting a gram of ice. 540 for evaporating a gram of water. It’s dramatically the case that evaporation of water matters a lot more than melting ice, and both of them make “warming water” look like an irrelevant thing.
Warming water is 1/80 as important as melting ice, and it is 1/540 th as important as evaporation of the surface of the water. Warming air is another order of magnitude less important to heat content.
So to have clue, one MUST look at the evaporation of water from the oceans as everything else is in the small change.
Look at any photo of the Earth from space. The Blue Marble covered in clouds. Water and clouds. The product of evaporation, convection, and condensation. Physical flows carrying all that heat (“vibration of atoms” and NOT temperature, remember). IF you add more heat energy, you can speed up the flows, but it will not cause a huge increase in temperature (and mostly none at all). It is mass flow that changes. The number of vibrating molecules at a temperature, not the temperature of each.
In the end, a lot of mass flow happens, lofting all that water vapor with all that heat of vaporization way up toward the Stratosphere. This is why we have a troposphere, a tropopause (where it runs out of steam… literally…) and a stratosphere.
What happens when it gets to the stratosphere boundary? Well, along the way that water vapor turns into water liquid very tiny drops (clouds) and eventually condenses to big drops of water (rain) and some of it even freezes (hail, snow, etc.). Now think about that for a minute. That’s 540 calories per gram of heat (molecular vibration NOT temperature, remember) being “dumped” way up high in the top of the troposphere as it condenses, and another 80 / gram if if freezes. 620 total. That’s just huge.
This is WHY we have a globe covered with rain, snow, hail, etc. etc. THAT is all that heat moving. NOT any IR Radiation from the surface. Let that sink in a minute. Fix it in your mind. WATER and ICE and Water Vapor are what moves the heat, not radiation. We ski on it, swim in it, have it water our crops and flood the land. That’s huge and it is ALL evidence of heat flows via heat of vaporization and fusion of water.
It is all those giga-tons of water cycling to snow, ice and rain, then falling back to be lofted again as evaporation in the next cycle. That’s what moves the heat to the stratosphere where CO2 then radiates it to space (after all, radiation toward the surface hits that closed IR window and stops.) At most, more CO2 can let the Stratosphere radiate (and “cool”) better. It can not make the Troposphere any less convective and non-radiative.
Then any more energy “trapped” at the surface would just run the mass transport water cycle faster. It would not increase the temperature.
More molecules would move, but at a limit on temperature. Homeostasis wins. We can see this already in the Sub-Tropics. As the seasons move to fall and winter, water flows slow dramatically. I have to water my Florida lawn and garden. As the seasons move to spring and summer, the mass flow picks up dramatically. Eventually reaching hurricane size. Dumping up to FEET of condensed water (that all started as warm water vapor evaporating from the ocean). It is presently headed for about 72 F today (and no rain). At the peak of hurricane season, we get to about 84 or 85 F ocean surface temperature as the water vapor cycle is running full blast and we get “frog strangler” levels of rain. That’s the difference. Slow water cycle or fast.
IF (and it is only an “if”, not a when) you could manage to increase the heat at the surface of the planet in, say, Alaska: At most you would get a bit more rain in summer, a bit more snow in winter, and MAYBE only a slight possible, of one or two days that are rain which could have been snow or sleet.
Then there’s the fact that natural cycles swamp all of that CO2 fantasy anyway. The Sun, as just one example, had a large change of IR / UV levels with both the Great Pacific Climate Shift (about 1975) and then back again in about 2000. Planetary tilt, wobble, eccentricity of the orbit and more put us in ice ages (as we ARE right now, but in an “interglacial” in this ice age… a nice period of warmth that WILL end) and pulls us out of them. Glacials and interglacials come and go on various cycles (100,000 years, 40,000 years, and 12,000 year interglacials – ours ending now, but slowly). The simple fact is that Nature Dominates, and we are just not relevant. To think we are is hubris of the highest order.
See Also Bill Gray: H20 is Climate Control Knob, not CO2
via Science Matters
February 12, 2023 at 01:07PM