I Misunderstood the Greenhouse Effect. Here's How It Works.

[@SabineHossenfelder]

We have an infographic to go with the video that you can download here: www.dropbox.com/s/mhlu3b8f53pjz9t/Infographic%20Greenhouse%20Gases.jpg?dl=0

[@arnswine]

Shouldn't middle depiction (#2) indicate red band of hotness near surface (where it matters most to plants and aminals)?

[@Bob-of-Zoid]

I'm just happy to have great greenhouse tomatoes in winter! 😋YUM! Vielen dank Sabine!

[@SabineHossenfelder]

@@arnswine It would have been too difficult to depict the difference to the final picture, so we dropped that.

[@ThePowerLover]

TOO "dumbed down" if you want "rational" people to believe you!

[@albertvanlingen7590]

Past climate has seen CO2 levels at 6000ppm so did humans cause those levels?? Plants die below 120ppm....think about that. But don't worry I don't want you to wiggle about losing your monetisation.

[@renatanovato9460]

I usually understand things easily when Sabine explains. Not this time, though. I will have to watch it once more.

[@florisv559]

I'm with you. This is really difficult.

[@dsp3ncr1]

Well, unfortunately it's still not right. That's just not really how a greenhouse works. Greenhouses work by preventing conduction/mixing of the warmed air with the cooler air above it.

[@marcwinkler]

Let's try... Greenhouse effect works in a building with roof and sides made of glass. Beware of False Analogies.

[@mikesmit6663]

i normally have to Sabines videos several times to get a thorough understanding. please don’t feel alone

[@haukenot3345]

@@dsp3ncr1 Let me make sure I get this right: Your point is only that the metaphor doesn't exactly fit, not that any part of the actual explanation is wrong, is it?

[@Biga101011]

When I first went to college I wanted to educate myself on climate change. I took a course on environmental science hoping to get a better understanding. Unfortunately I didn't realize the course was a sociology course, so we didn't actually learn anything about climate change or the environment. Instead it was about people's perception of the topics. An environmental economics course I took a couple years later was actually very good and useful, but still never really got a good understanding of the principles behind climate change. It is amazing how for such an important topic most of the conversation about it seems to not actually revolve around what it is.

[@PhysicsLaure]

I had a similar issue, but my course was 100% energy management (dams, solar, etc vs needs over time and in different places). 😂

[@danielhutchinson6604]

In the Montana College in Missoula, the effects of Greenhouse Gas emissions are taught by a pretty good Common Sense Educator. Steve Running has received recognition for his efforts to understand one of the most prominent polluters in the Western US, at a small town called Coalstrip. We may be fortunate to discuss local effects of economic demands on facts that are presented by internet websites, but facts do matter, and we all need to look at all of the effects that money can buy?

[@ericvulgate]

Similar to the dialogue around corona..

[@illustriouschin]

Yeah you could have saved yourself a lot of time and money by watching a 20 minute video that just agreed with your prejudices.

[@philipm3173]

If your school's environmental economics was anything like mine, you can completely disregard it. Carbon credits, cap and trade, all these things are utterly ineffective. There's only one solution, seizing all private petroleum assets and shutting them down.

[@alexanderkohler6439]

I really liked this episode, however, I think the explanation at 6:45 - 7:15 of why the roundness of earth and the inverse square law for gravitiy were relevant and why the pressure decreased with the height above the earth is totally incorrect. The pressure doesn't decrease due to the decreasing gravitational pull. In fact, the latter almost stays constant in that area. What changes, is the remaining amount of air above you that has a weight and thus exerts pressure on you. The same principle applies in water. You observe a higher water pressure at the ground of a swimming pool than at its surface. Again, that is not due to a higher gravitational pull, but due to a higher amount of water above you.

[@fares_of_arabia]

Thant also works on flat surfuces, no balls needed thank you.

[@starstenaal527]

And what exactly causes the air above you to get pushed down on you if not gravity?

[@fares_of_arabia]

@@starstenaal527 and what.....gravity does not work on a flat surfaces, or are you going to give me earth magnetic core bullshit, have you been to the earth core.....no.....so...do don't tell me what is there underneath the so called core, because you don't know either....

[@revanwallace]

@@starstenaal527Gravity indeed causes air pressure in that gravity gives air weight; but it is NOT the decrease in gravity with altitude that causes the decrease in air pressure with altitude. The reason for that is much simpler: the higher you go in the atmosphere, there will a lesser weight of air above you pushing down.

[@starstenaal527]

​@@revanwallaceAgreed.

[@KruczLorand]

the pressure of the atmosphere doesn't decrease with height due to the inverse square law of gravity being weaker. The difference in gravitational acceleration is negligable from the surface to 100km high which is where space begins. The pressure decreases because is given by the weight of the column of air above and as you move towards space that columns is less and less massive.

[@SimonFrack]

Same reason pressure increases with water depth, yes?

[@albripi]

I noticed that error, too

[@miked5106]

Isn't energy moving thru the atmosphere via convection vs radiation at least until it reaches the higher elevation where the air is scarce?

[@brianmacker1288]

​@@miked5106It is both radiation and convection yes. But another major effect is atmospheric heat piping by water vapor. Look up a heat pipe and how it functions. Now realize that water has a high heat of vaporization and condensation. Note the fact water vapor is lighter than air and convects upward, plus is a infrared absorbtive and radiative gas. These properties cause the water cycle to act as a natural heat pipe. Water evaporates at the surface, capturing the heat of vaporation at low elevation. That latent heat of vaporization cannot be lost by radiation back to the surface unless it condenses. The water vapor can then also warm radiatively by absorbing more infrared heat from the surface, or warm CO2 in the atmosphere. High humidity air being lighter than dry air it rises. Rising above a significant amount of CO2 which is denser than air so stays relatively lower. At cloud height it cools to the point it condenses, releasing its enormous load of latent heat of condensation, and radiates above most CO2. The cold rain falls back to earth cooling the surface. The cloud also reflects incoming solar radiation. Every raindrop represents a net cooling done by this natural heat pipe. Heat had to have radiated to space for it to condense and fall back.

[@7071SydcHome]

@@SimonFrack I'd say that is correct.

[@AlanTheBeast100]

@07:00 the falling gravity with altitude has negligible effect on the pressure gradient. The pressure gradient is mostly due the weight of the air column - densest at the bottom due to all the weight piled on it from above. About 50% of the atmosphere (by mass) is in the first 5000 metres or so. Earth's gravity potential at 100,000 metres is 0.97g. Has pretty much no effect on the change of air pressure (density) with altitude. As to GH effect: I had the same issue up until this video: kzbin.info/www/bejne/noapgKileZiUftk&ab_channel=SixtySymbols

[@pompeymonkey3271]

I noticed that too. But it did not detract from the overall science :)

[@ephemerallyfe]

There are also no satellites orbiting Earth in the stratosphere.

[@AlanTheBeast100]

@@ephemerallyfe I did hear something odd there but didn't go back for a re-hear.

[@AlanTheBeast100]

@@pompeymonkey3271 It's so fundamental, that, well, it detracts from "overall science" if not this specific topic.

[@paulramsey2000]

I came looking for this this comment. I was surprised that she made that mistake. I'm sure she'll hear about it. It's fundamental enough that hopefully she'll provide a correction but I agree that it was overall a great video.

[@Sean-ll5cm]

Everything's always so much more complicated than it seems 😭

[@davideyres955]

That’s the thing with chaotic systems. Complicated and very hard to model. This is the problem with the narrative and how they are using it. There are plenty of things we can do to increase the efficiency of the consumption but we are tackling things we want to not the things that will make a real difference. For example aerogel insulation is about twice as good as PIR insulation but we are not subsidising it and ensuring it’s used in construction. It’s postulated that you could heat a house insulated with aerogel with a candle.

[@MeppyMan]

@@davideyres955 “the narrative” and “how they are using it”. Sigh.

[@MaGaO]

@@toungewizzard6994 The video specifically shows why the greenhouse effect doesn't happen because of the Sun: it just provides the energy.

[@borttorbbq2556]

Hey you think you understand something in science you probably don't

[@georgesheffield1580]

Only for simpletons

[@delveling]

I didn't realize that this subject is so complicated, i almost took a break and went back to watching quantum mechanic videos to clear my mind a little, thank you for the enlightening explanation.

[@kayakMike1000]

At best, it's really saying is CO2 in the atmosphere is increasing without saying that CO2 is increasing in the atmosphere. There's a slight cooling effect, apparently, because CO2 emits infrared efficiently is sparse atmospheres, I guess... I guess carbon dioxide doesn't act like an ideal black body. And this cooling effect is observed in one model from 1968, so all the models must be correct.

[@grindupBaker]

​ @kayakMike1000 "this cooling effect is observed in one model" S.B. "this cooling effect is measured by instruments on satellites since 1964".

[@mokiloke]

Yeah, me too lol, and i did these subjects at Uni, but my brain still hurts

[@MrJdsenior]

If you think quantum mechanics is simpler than this, I would question your grasp of quantum mechanics, or your relative time spent thinking and learning about each of the two subjects, at least. There IS NO understanding of a lot of quantum mechanics. A lot of it is just a bunch of hand waving. There's a quote Feynman supposedly made that went something like: If you think you understand quantum mechanics, you don't, which is basically what I said, though his is much more concise, and he was a leader the field in some aspects, those crazy diagrams, where I am mostly clueless. I just remember all the "A miracle occurs here" when I was learning about it in an introductory course as the core for an engineering degree, and that hand waving occurred a lot more than once, IIRC. Or was that a joke? If so, good one. :-) I saw quantum well FLIR detectors and the like, but I can tell you for a fact that if I were the only one trying to develop them, they wouldn't exist.

[@kayakMike1000]

@@grindupBaker jokes on you duder, the poles have a tremendous amount of hot air in the stratosphere and there's colder than expected air in the tropical troposphere. Could it be that there are cycles?

[@solapowsj25]

So' is why venus is hotter than Mercury.

[@sentinel2199]

Sadly it's even more complicated than that. The greenhouse effect causes less than 50% of the warming effect predicted from increasing CO2, with the remainder being caused by climate feedback effects: There are a huge number of climate feedbacks, but a simple example of a "positive feedback" is that white snow reflects sunlight, but once it's melted by a warming environment, then more sunlight will be absorbed by the ground, and so the temperature will increase further (so causing even more snow to be melted, etc). An example of a "negative feedback" is that as temperature increases, there is more evaporation from the ocean, which causes more clouds to form in the lower atmosphere, reflecting more sunlight into outer space, so reducing temperature. Unfortunately these feedback effects are often not understood very well (as they are often hard to measure), hence the large variation in predictions made by different climate models (and so why the IPCC prefers to average over a large number of models). In the distant past there was probably a period known as the Snowball Earth where most(*) of the surface was covered in ice (reflecting sunlight into space) from a massive ice age, and without volcanism producing CO2 the Earth might still have been like that today. (* I have simplified to avoid writing too much.)

[@bluebristolian]

The feedbacks are clearly negative. Systems with positive feedbacks are unstable, so if it could it would have already, and we’d have been in runaway global warming for billions of years. Unfortunately Sabine is missing the big picture.

[@sentinel2199]

@@bluebristolian Climate scientists use "positive feedback" in a slightly different sense to how electronics engineers (and possibly others) use it. When they say "positive feedback" they mean that the loop gain is > 0 but < 1, and so is still basically stable (but may have oscillations that will die out). You can think of a CO2-induced temperature gain of (say) 0.8C, producing 0.4C further increase from positive feedback, which then produces 0.2C of further increase from positive feedback (on itself!), which then produces 0.1C of further increase, etc. In this simple case the overall gain would be end-up as 1.6C, thus doubling the original CO2-induced temperature change. The real climate is of course rather more complicated, with different feedbacks operating on vastly different time scales.

[@sentinel2199]

It seems my follow-up post has been auto-blocked by KZbin, possibly due to me including links for reference. What I basically said is that the sum of positive+negative feedbacks is known as "climate sensitivity". The IPCC's best estimate of climate sensitivity is that a doubling of CO2 will cause a temperature increase of 2.5C to 4C. But without ANY feedbacks (i.e. just the physics mentioned in this video) CO2 would only increase temperature by about 1C (this is a non-controversial statement!). Thus CO2's physically direct contribution is only 1/2.5 to 1/4 of the total warming effect (i.e. 40% to 25%).

[@sentinel2199]

Sorry, I don't use either of those apps, but anyway I'm just a science nerd with a passing interest in climate science 🙂

[@richardatkinson4710]

Well, I’m no scientist either, but I can read; so with trepidation… There’s still a missing feature, which is the fact that evapotranspiration + convection is responsible for carrying away a large fraction of surface heat as the latent heat of evaporation. At the cold trap, water condenses (OK, I know that this is complicated by the need for condensation nuclei) and the heat is radiated away into space. It’s the reason we are not, and will never be, at rusk of runaway global warming. The big question, which I can’t see clearly covered in the IPCC science sections, is how this is affected by changes in surface temperature. You’d naively expect a strong negative feedback. But (witness Sabine’s presentation and your own reply) nobody seems to be talking about it one way or the other.

[@tayzonday]

Wow! So we’d be an ice planet with no greenhouse effect.

[@markotrieste]

There is a hypothesis that Earth actually went through a "snowball planet" period.

[@MagruderSpoots]

Then you'd have to sing about chocolate snow.

[@msytdc1577]

@@MagruderSpoots chocolate glaciers kilometers thick, MmmMMmMMm 🥹

[@Patatmetmayo]

The Earth has been through much colder and much warmer periods. It's crazy to think for example that in 10000 years from now our seasons will be reversed, it will be Summer where it is now Winter, and Winter where it's currently Summer. The hypothesis that CO2 has such a big influence on global temperature is really not as scientifically solid as we are being led to believe.

[@enadegheeghaghe6369]

@@Patatmetmayo the part you missed is that we did not have 8 billion people on the planet during those much warmer or colder times in the past.

[@trevorcrowley5748]

"It Is Difficult to Get a Man to Understand Something When His Salary Depends Upon His Not Understanding It"

[@techcafe0]

hear! hear!

[@stapleman007]

"It is impossible to change a man's belief when he is being paid to believe."

[@einhalbesbrot]

​@@stapleman007why would it be impossible? Pay more!

[@leeadickes7235]

Or funding from a university

[@tarant315]

​@@einhalbesbrotdid you hear how much those co2 extractor made on profits last year

[@guenthermichaels5303]

Stratospheric Cooling. That is the net proof that I didn't know before.

[@grindupBaker]

Absolutely and I've been pointing that out for 8 years, but it's hard to argue against the so-called "greenhouse effect" in Earth's troposphere anyway when it's (Earth's radiation to space) been actually measured continuously by satellite instrument since 1964 (IRIS-A on Nimbus 1) and is clearly seen in the sample FTIRS over the Internet the last couple of decades including GooglesTubes videos such as: === at 16:35 at kzbin.info/www/bejne/rGPRmaaphbxqbas and 20:31 (3 FTIR samples measured in 1970 for Sahara Desert, Mediterranean Sea & Antarctica) === at 18:08 at kzbin.info/www/bejne/haDKaGCBhNmje6M (4 FTIR samples for western tropical Pacific Ocean, Sahara Desert, Antarctica & southern Iraq) === at 30:55 at kzbin.info/www/bejne/qV7Ek2CQg72hkJo (3 FTIR samples measured in 1970 for Sahara Desert, Mediterranean Sea & Antarctica again) === at 20:09 at kzbin.info/www/bejne/qJizXp-tm5enmJo (3 FTIR samples measured in 1970 for Sahara Desert, Mediterranean Sea & Antarctica again) and for this one at 22:09 to 22:34 hear Professor William van Wijngaarden of York University Toronto who did the study with William Happer explain clearly why the "greenhouse effect" in Earth's troposphere works backwards and COOLS THE SURFACE of Antarctica in winter (but only Antarctica and only in winter) for the same reason "greenhouse effect" cools the stratosphere. === at 2:37 at kzbin.info/www/bejne/hH_Kfqx6h7yKqKM for 63,000 locations around Earth (grid pixels) measured presumably hundreds or thousands of times at each place from space (averaged) both the radiation both the radiation power emitted to space, after being filtered through the "greenhouse effect" and also the surface temperature below that radiation, so it's a fairly accurate measure of how much warming, or COOLING, effect there is at all locations around Earth due to "greenhouse effect", which COOLS when surface is below -45 degrees, as shown, and warms when surface is above -45 degrees, with the warming effect getting stronger as the surface gets warmer. Interesting science stuff. IMPORTANT: This green hash-plot is only for when there were NO CLOUDS IN THE SKY so that it gets the effects or the IR-active gases only and doesn't get interfered with by clouds, which have their own often extremely-powerful version of the "greenhouse effect" (they keep winter nights much warmer than with a clear sky, often dramatically so).

[@aDifferentJT]

Air pressure doesn’t decrease with altitude because the gravitational force decreases, in a uniform gravitational field the air pressure would also decrease, and the gravitational force in LEO is pretty similar to that on the surface. It decreases because the mass of air above that point is lower.

[@55dionysus]

So the gravitational force is uniform across any distance ? The weight of the air mass isn't created by gravity and its distance ? I can picture pressure decreasing as the air gets thinner above it , but I thought that was the effect of gravity and distance .

[@wirbelfeld4033]

She corrects this in the description

[@MovieViking]

Correct, Sabine corrected this in the description: "Correction to what I say at 7 mins 13: The major reason air pressure decreases is that the gravitational pressure from the air above it decreases. The gravitational force itself also decreases but that's a rather minor contribution. Sorry about that, a rather stupid brain-fart. "

[@joejoejoejoejoejoe4391]

If that was true, then pressure would increase with the depth of the oceans, - oh, wait, it does!

[@peterja6441]

nope. the air molecules just have a velocity distribution at a given temperature. the kinetic energy of the molecules is what makes the atmosphere "terminate" at certain altitude - there are just not enough molecules to go any higher. remember classical gas is mostly Boltzmann distributed, means there are exponentially less molecules with higher and higher energy. thats also the reason why the air is getting exponentially thinner if you go to higher altitudes

[@Elloziano]

Very necessary video, my favorite channel never fails to deliver!

[@sillysad3198]

absolutely necessary! to not being fired, and trown out of youtube.

[@armouredghoul8279]

R E C Y C L I N G is a sc4m

[@armouredghoul8279]

C0mpanies didn't want to stop using plastic so they blamed us for not "R E C Y C L I N G"

[@armouredghoul8279]

Use glass bottles instead and wash them.

[@monicabello3527]

@@armouredghoul8279simply drink tap water😜

[@prydin]

Sabine! A good science communicator is one who’s not afraid to say “this is more complicated than you think”. Thank you again for the great content you put out!

[@kanguruster]

Sabine is also a good enough communicator to say "this is more complicated than even I thought, so I further educated myself."

[@jovetj]

It's always "more complicated than you think"...

[@msimon6808]

It has to be very complicated to use water vapor and then make it disappear. Magic. Magic is not science. Water vapor is the #1 Greenhouse gas. It does 3/4s of the heating according to GHG theory. If you can believe the theory. If the theory is correct water vapor alone will destroy the planet. There is on average 50 times as much water vapor in the atmosphere as CO2.

[@msimon6808]

@@kanguruster It has to be complicated. To cover this up. Water vapor is the #1 Greenhouse gas. It does 3/4s of the heating according to GHG theory. If you can believe the theory. If the theory is correct water vapor alone will destroy the planet. There is on average 50 times as much water vapor in the atmosphere as CO2.

[@Bob-of-Zoid]

I wish flat earthers would realize that some things are harder than just "It looks flat to me" and then assume all of science must therefore be wrong!

[@Patrick-kq9fy]

Having been involved in radio technology for most my life, I understood the "wiggling" a different way. I think of a molecule as a kind of antenna tuned to a specific frequency and associated harmonics. So... Basically a molecule like H2O or CO2 is like an antenna that is tuned to certain frequencies that, when excited, resonates (vibrates, wiggles)... or you can think of it like a tuning fork. Just as a tuning fork emits a specific sound regardless of what causes it to vibrate, a CO2 molecule resonates at specific frequencies of the EM spectrum. So... that's my understanding.

[@grindupBaker]

Sure that's good enough for sure, whatever turns your crank. Greenhouse Effect is that top of troposphere is (much) colder than bottom of troposphere and colder bunches of molecules make less radiation than warmer bunches of molecules, and top of troposphere is closer to space and bottom of troposphere is closer to surface. That's it.

[@farleftsilencelikenazis1021]

@@grindupBaker The Earth does not even cool at a wavelength affected by CO2. After saturation the reflective bands do nothing. Just as a strip of SPF 50 sun cream will not keep your body cooler. Wood, R. W. (1909). XXIV. Note on the Theory of the Greenhouse. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 17(98), 319-320. who demonstrates that longwave infrared radiation is not trapped by atmospheric greenhouse gases. Human contribution to the planet's 0,04% CO2 is just 5% and absorbed within 11 years. The warming is caused by climate cycles with varying periods. Eg a 2300 year Bray, A 65 year Gleisberg, a 240ish De-Vries / Yoshimura as happened in the medieval warm period, when the peaks coincide = Warming. Note the warming started way before the industrial era. Also past CO2 is claimed to not be over 280PPM for 100's of 1000's of years. That is also a big fat lie because they use a bad proxy to fool the people with a BS hockey stick graph. eg here Co2 was more than today just 12000 years ago. "Steinthorsdottir, M., Wohlfarth, B., Kylander, M. E., Blaauw, M., & Reimer, P. J. (2013). Stomatal proxy record of CO 2 concentrations from the last termination suggests an important role for CO 2 at climate change transitions. Quaternary science reviews, 68, 43-58. " Also Greenhouse gas theory is proven false. ALL gasses make up the heat sink that forms the atmosphere. As PROVEN here below. IF we could double CO2 the temperature rise would be +0.1C There is no debunking or scientific rebuttal to these 2 papers. One uses the ideal gas law and calculates the temperature of all planets with a thick atmosphere which can be verified with instruments as being accurate. There is NO CLIMATE EMERGENCY. There IS a lot of cherry picking, data manipulation and "Smoothing" (eg to make the same warming period we experience now disappear in order to sell the lies) Holmes, Robert. (2018). Thermal Enhancement on Planetary Bodies and the Relevance of the Molar Mass Version of the Ideal Gas Law to the Null Hypothesis of Climate Change. Earth Sciences. 7. 10.11648/j.earth.20180703.13. Nikolov N, Zeller K (2017) New Insights on the Physical Nature of the Atmospheric Greenhouse Effect Deduced from an Empirical Planetary Temperature Model. Environ Pollut Climate Change 1: 112.

[@AndrewBurbo-zw6pf]

so you would understand what a PHD fro MIT told me, CO2 is a band pass filter that is saturated at about 100 feet of air and increasing the concentration only saturates it in about 75 feet,meaning there is virtually no possible change in what gets through in 10,000 feet

[@paulbloom7544]

I'm a PhD Physicist who teaches general education climate science (when I don't have to teach the physics curriculum). This is an outstanding and clear presentation of how the greenhouse effect actually works (which I didn't fully appreciate for the first too many years I taught the class). The way you propose to modify the energy flow diagrams is spot on. Definitely some of your best work. Brava, and thank you for doing this. Heck, gonna show it in my class...

[@arm-power]

I would like to know the worst case scenario: What if we burn all those fossil fuel? From the science point of view there were period of time on Earth when all that fossils plants were alive on planet surface (before there were buried underground and fossilization process started). Lets put aside the process how those plants were buried - that catastrophic event (wipe out and buried Earth surface) is much more dangerous for humanity than climate change itself. - How high air temperature were? - How much would human civilization needed to adopt for that worst case? - And the most important one, how many centuries it would take to get the worst case if we continue in fossil fuel burn (including growth of population) I assume there would be no ice caps and Earth. Rising ocean levels is easy to handle as housing building speed (area per year) is much higher than area taken by ocean per year. Also with that high CO2 concentration whole planet would be incredibly green and food rich.

[@tortysoft]

@@arm-power It is the massive changes that would be required from human population and governments to accommodate the environmental climate movements that would kill us. We can easily live on a 'warmer' planet Earth - but in different places on Earth. It's getting through the climate wars that will be the problem. We are in one of them now.

[@valentinmalinov8424]

Will be good also to tell your students that that CO2 is not stopping the heat, but is re-emitting the heat in all directions. That means that CO2 also stops the heat coming from the Sun. Also, any warming will increase dramatically the water evaporation of the oceans, and the white cloud cover will block and reflect back most of the incoming sunlight.

[@michaelstorm1007]

Can you explain why "the ditch" gets wider with altitude when more CO2 is added.

[@boohoo746]

but it is a terrible presentation when it attempts to pass judgment on climate change. the woman appears to be unaware the clouds are made of water vapor and have high albedo. she also seems to be unaware of ocean heat transport, solar-induced destruction of polar ozone, etc.

[@himbeertoni08]

Wow, that just blew my mind! I've a phD in physics and still had exactly the same misunderstanding. I think, it's not just the arrows in the diagram, but most sources of information trying to make the complex topic understandable. Kind of similar to the various atomic models out there in schools and the web, which are scientifically all oversimplified, thus wrong when it comes to explaining chemistry (Schrödinger and Dirac are nodding).

[@SpectatorAlius]

Are you referring to the Bohr Model, or to Lewis diagrams? If the former, its inadequacy is itself often overstated. And here's a factoid about that may change the way you see it: in the QM model for the atom, the points of local maximum probability for finding the electron correspond to the Bohr orbit.

[@davidconner-shover51]

Curses Bohr!

[@himbeertoni08]

I had Bohr's model in mind, but Lewis notation is another great example. Following Bohr's model, the orbital model did improve on what could be explained. Schrodinger's equation was improved by Dirac to include relativistic effects. We ever improve our models, but in the end they are all limited. Such is the greenhouse model for climate change.

[@dsp3ncr1]

If you take that -18C prediction for Earth's radiative equilibrium temperature and, (for modeling/prediction purposes), say that that temperature occurs 5km up in the atmosphere and then apply the ideal gas law what would you predict the temperature of the air at sea level to be?

[@afterthesmash]

You need to check out Doug McLean's "Common Misconceptions in Aerodynamics" on KZbin from October 2013. He's a retired Boeing Technical Fellow who explains to other Boeing engineers that what they thought they knew about Navier-Stokes is all wet. Around 26:00 he explains that there's a reciprocal cause-and-effect relationship between velocity and pressure. If you manage to wade through the vorticity field due to the Biot-Savart law without hitting pause, you're a much better physicist than I would have even been, had I not taking the other fork in the road into computer science instead.

[@mathewkolakwsk]

Thank you for continuing to tackle very complicated topics! You put your explanations into context very well. Specifically, your explanation here is helpful and assumes we aren’t all too ignorant or stupid, or bad faith actors. Thanks again!

[@Kenneth-ts7bp]

But you don't understand the physics, nor do any climate alarmists.

[@mathewkolakwsk]

@@Kenneth-ts7bp So-called climate alarmists (or climatologists, in part) have been saying the same thing for decades - and the data supports what they’ve been saying. Glaciers are receding, the average temperature on the surface of the planet is going up… and the mechanisms for why this is happening is understood (well enough). What do you know that everyone else doesn’t?

[@Kenneth-ts7bp]

@Mathew Kolakowski I understand physics. That's the difference. Anyone who claims CO2 can overheat the planet is clueless and doesn't understand physics. Isn't it ironic that CO2 just keeps increasing agricultural output and not overheating the planet. Why do you think they call Greenland Greenland?

[@Kenneth-ts7bp]

@Mathew Kolakowski It's pretty obvious Sabine doesn't understand greenhouse gases and she's just parroting what someone told her. She made the claim CO2 blocks all outgoing infrared; that is just patently false. It blocks very little and doesn't radiate heat to Earth. If CO2 radiated all its heat, which is very little, it wouldn't rise in the atmosphere. Without greenhouse gases, the Earth would be hotter and colder. Why do you think CO2 rises out of the oceans? What is it doing when it does that?

[@libearl828]

The co2 from jets in the stratosphere is capturing infrared warming the air

[@PhysicsLaure]

Powerful analogies are great to give people a sense of physical concepts, but they can also lead us to false reasoning. 😑 Loving your content, I also had the same confusion as you before studying it. :)

[@hugegamer5988]

You can lead a horse to water, but you can’t make it calculate quaternions to simplify special relativity calculations.

[@benmcelwain5301]

Agreed. Hawking radiation with virtual particles handed me the wrong stick for a while.

[@0x0michael]

Neil deGrasse Tyson needs to hear this

[@TimeTheory2099]

So what was her conclusion? Reducing carbon gas is a waste of money? It's obvious the planet is warming, satellite photos prove that. Wouldn't reducing CO gas slow the effect?

[@Mavrik9000]

@@TimeTheory2099 Global warming is still a serious problem. The atmospheric mechanism that causes it is a bit more complicated than the standard analogies explain. And most educational illustrations are incorrect as they are overly simplified.

[@dmd7472]

I was with you until you said the earth is round. Can’t buy into propaganda.

[@kefhomepage]

And what shape , do you think it is 🤔. It's a sphere period

[@techcafe0]

@@kefhomepage ever hear of the expression, tongue in cheek? i'm pretty sure DMD was being facetious.

[@stapleman007]

You have two options: 1) Earth is round, space is flat 2) Earth is flat, space is curved.

[@photonjones5908]

There is a point somehwere along the learning curve, where one realizes how little one actually understands. Yet that is the gateway from ignorance toward a true grasp of a subject. We have all been somewhat misled by simplistic models, sadly most never reach the point where they recognize that they were misled. Anyway your video has also helped me to remedy my own misunderstanding that I had become aware of, and which brought me here for a proper explanation of the machanism of thermal forcing in AGW. Thank you Sabine.

[@irgendwieanders2121]

Actually trying to recreate some research helps (or at least helped me). Reading the paper (or actually the 2 papers we started from) I thought it was easy, half a year later, having dug through 3 layers of references I knew it was easy, but not like I at first thought it was ;-)

[@Kenneth-ts7bp]

You still don't understand.

[@jakecostanza802]

A or B? A: we don’t fully understand climate change, let’s ignore it. B: we don’t fully understand climate change, let’s be cautious.

[@BenBurkeSydney]

@@jakecostanza802 B would be my answer...

[@voidisyinyangvoidisyinyang885]

@@irgendwieanders2121 I emailed this vid to Professor Raymond Pierrehumbert and he replied that Sabine had asked him questions just to clarify his research. She's done an excellent job to make his research more easily understood!! So I find this very exciting.

[@FreddieVee]

Great video and fantastic explanation...BUT, When I am conversing with people who have differing views on "Global Climate Change" ( aka: Global Warming ), there are 5 choices: 1) Global Climate Change is a myth, 2) Global Climate Change is true, but it is not caused by human activity, 3) Global Climate Change is true, and even though it is caused by human activity, there is nothing we can do about it, 4) Global Climate Change is true, it is caused by the actions of humans, but if we do anything about it, we will bankrupt the world's economy, 5) Global Climate Change is true, it is caused by human activity, and we can do something about, without bankrupting the world's economy. I believed in ( 5 ) before I watched the video and I still believe in ( 5 ).

[@pleskbruce]

Very well said and I think that if you and I hashed it out we'd find we agree almost 100%. The climate is changing some but we have no idea what percentage if any is caused by human activities. Reality being what it is the vast majority of the world's population will never go along with the cutbacks needed to even have any hope of putting a dent in carbon emissions and even if that were successful we have no idea if it would change world temperatures by even a fraction of one degree. The Earth is a wonderful ecosystem with checks and balances that have been with us since the beginning. All of the money that appears to be needed to simply fight global warming is equivalent to spending a million dollars on a lottery ticket where the winning is worth so many people are willing to blindly jump into the climate change narrative and they have no idea how it really works.

[@kerryatkins3656]

IMO, if all the nations of the earth reduce their emissions, like North America, Western Europe, and other places, this would greatly reduce greenhouse emissions. There is more than enough wealth in the world to help the nations that need financial help and assistance to reduce greenhouse emissions to do it. it’s just like the food supply there’s more than enough food to feed everybody in the world but the current system just doesn’t get the food to everyone that needs it or for that matter adequate housing and adequate access to medical treatment and clean water. Men’s inhumanity to man is the biggest problem of all, IMO!

[@uldissprogis5138]

Sabine, you still didn't answer the most important question with an explanation. How many degrees does the earth's atmosphere increase with a 1% increase in carbon dioxide? Best wishes. Uldis

[@kevpatguiriot]

.

[@Ikbeneengeit]

You're talking with much more intelligent climate change deniers than I am. Mine mostly start by telling me science is a conspiracy.

[@stapleman007]

Once you get past 'conspiracy', there is 'consensus'. After that is 'settled'. You have much to learn grasshopper.

[@symmetrie_bruch]

that´s a very good way of doing things. explaining it on different levels of understanding and shows how easy it can be to sometimes, even inadvertantly, lie by omission. theres this terrible stupid quote that´s often misatributed to einstein, that if you can´t explain it to a six year old you don´t understand it yourself. that often leads to oversimplifying things to the point of being wrong. no, that´s not how things work, 6 year olds are idiots and some questions require much much more explaining and/or prior knowledge than a six year old could understand. i think that´s one of the single most often used and dangerous exploits liars and con men use because it´s so damn effective. offering easy answers to complicated problems.

[@primovid]

The disappointing part of this video, Sabine, is that you are downplaying the effects of global climate change by making incorrect and oversimplified statements like this: "Not a big change for the planet, but a big change for us because we have made ourselves comfortable on this planet with a different climate" This sentence should read: "Not a big change in temperature for the GEOLOGICAL planet, BUT A BIG CHANGE FOR ALL LIFE ON EARTH because ALL LIFE HAS ACCLIMATED TO THIS PLANET AT A LOWER TEMPERATURE OVER MILLIONS OF YEARS"

[@mrunning10]

What are you doing to help fix this fucking fossil fuel mess? Anything??

[@dougselsam5393]

I've been a big fan of Sabine for some time. Usually though, while I am scientifically trained, I can barely understand the science she presents due to the advanced and specialized subject matter she tends to promote, so I'm mostly taking her word for it. However in watching THIS video, I was pretty-well tuned-in, and found myself appalled at what Sabine was saying, starting around the 7:00 mark. She correctly mentioned Newton's inverse-square law for gravity (meaning gravity decreases with the square of the distance from the CENTER of Earth), but it seems that she actually severely misinterpreted Newton's law of gravity, thinking that gravity decreases in proportion to the distance from the SURFACE of the Earth. Nope, it's the distance from the CENTER of the Earth. Earth's atmosphere is proportionally the thickness of the skin of an apple. That means gravity at 80 miles high is ABOUT THE SAME as gravity at the surface. Sabine however tried to explain the thinning of the atmosphere at high altitudes as the effect of less gravity higher in the atmosphere. This is wrong. There is almost zero difference in gravity from the surface, all the way up through 60-80 miles of atmosphere. (although almost all of the atmosphere is MUCH lower than 60 miles, or even 20 miles) Proportional to the ~4000-mile radius of the Earth, that 60-80 miles to "space" is a teeny fraction. The reason people feel weightless even in low Earth orbit is NOT due to significantly less actual gravity. It is due to the centrifugal force that keeps an orbiting spaceship and everything in it "perpetually falling" since the still-very-high-at-low-Earth-orbit gravity of Earth is counteracted by the centrifugal force generated by the orbit (speed) itself. So, being usually just accepting of Sabine's videos as "slightly over my head" I was surprised when I actually DID know something about what she was talking about, and how it struck me as completely wrong. That is a big red flag, for me anyway. The reason the atmosphere gets less dense with altitude is NOT because there is less gravity higher up in the atmosphere. The reason is THERE IS ONLY SO MUCH ATMOSPHERE. And the reason the atmosphere is more dense at lower levels is it is compressed by the cumulative weight of all the atmosphere above it. That bears repeating, so pay attention: The REASON the atmosphere is more dense at lower levels is it is compressed by the cumulative weight of all the atmosphere above it. It is definitely NOT because there is more gravity closer to the surface. In fact, if you think about it, if atmospheric density with altitude was proportional to decreasing gravity at the same altitude, airplanes could fly as high as their engines would work, because the lower amount of "lift" in thinner air would be matched by the airplane getting lighter and lighter as it got higher. But there is no such effect. Airplanes can only fly so high, because as the atmosphere gets MUCH thinner within a few miles of altitude, gravity is almost exactly the same as at the surface. I hope I'm explaining this sufficiently well for people to understand. Actually I think most people, at least most technically-oriented people, already know this. The explanation for the atmosphere getting thinner with altitude is something I can actually understand, and because I DO understand THIS science, I realize the I will have to take everything Sabine says with an extra grain of salt from now on, because she got that very SIMPLE science completely wrong. In fact, now that I think about it, the TEENY actual decrease in gravity with increasing altitude in the atmosphere would actually allow very slightly MORE air molecules to reach higher altitudes, ever-so-slightly REDUCING how much thinner the atmosphere gets with altitude, so she even got the direction of the basic effect wrong, let alone the proportion. While I love Sabine's maverick attitude, I'm going to have to pay more attention from now and, with less simple acceptance of what is being touted as fact, and a lot more skepticism. Also I will point out, having spent a lot of time in the high desert at 3600 feet altitude, the whole greenhouse gas effect is more about the Earth holding in heat AT NIGHT than during daytime. In the high desert of the South-West U.S., daytime temps can easily far exceed 100 degrees Fahrenheit, but just as the sun goes down, you go from no shirt to putting on sweatshirts if the air is clear and the sky is (was) blue. Nights in the clear, dry high desert air usually get chilly very quickly at sundown! (Very little greenhouse effect) BUT if there are clouds or even a haze in the air, it stays warm after sundown. This is especially apparent in winter when you can easily correlate cold nights with clear skies and warm nights with overcast or clouds, with water vapor being the main greenhouse gas. So, all these greenhouse gas explanations around daytime phenomenon are also not quite on target, not at all actually, and that goes across the board, not just Sabine. Greenhouse gasses work their magic AT NIGHT. They keep the dark half of Earth from going into arctic conditions every night. During the day, greenhouse gasses actually block infrared radiation from the sun from reaching the Earth's surface. Nobody ever mentions that... :)

[@Leschsmasher]

You are so right - 42% of the sun radiation are IR-radiation! The decreasing pressure in the atmosphere has absolutely nothing to do with gravity and so on. She isn`t a scientist- only a liar.

[@snoosebaum995]

and where is the diurnal temp range data ? supposed to show a decline

[@brianletter3545]

@@Leschsmasher " . . . only a liar." That is not only wrong but very unfair. Sabine admits she got the GH Effect wrong and she doesn't get it right here. But being wrong doesn't make one 'a liar' Please edit or withdraw. And, while you are at it, produce a better explanation . . !

[@dougselsam5393]

@@snoosebaum995 The daytime incoming IR blockage was already saturated or at a high level. The difference is mornings start out a teeny bit warmer, due to less heat lost to space at night. That makes daytime temps a little bit warmer than they would be if nights were colder.

[@TerryBollinger]

That was... intense! I think you covered most of the innards of the full model. One issue I didn't see is the criticality, complexity, and difficult-to-model fractal variability of the water vapor component. Without high water vapor averages, we'd be a giant snowball even with astronomical increases in durable CO2 and fragile-in-oxygen methane.

[@SabineHossenfelder]

Yes, that's right. I was about to go on about the relevance of water, but it just got too long. So I ended up just saying actually it's more complicated than that...

[@adamsuwaa1433]

Without story about water and clouds it is still only half-truth 🤔

[@rogerlie4176]

As Sabine pointed out, a 20 minutes video can only scratch the (warming) surface of an incredibly complex subject.

[@jjhhandk3974]

Then don't fuckin say you're going to explain it. 😂

[@msytdc1577]

@@rogerlie4176 I mean you can simply say upfront that "Both water vapor and greenhouse gases result in the green house effect, but this video is going to focus on the gasses-let me know in the comments of you'd like to see another video covering the water vapor aspect." Then with one sentence you covered your bases, let people know there's more to the (complicated) story, and driven some engagement (go go KZbin algo rhythm).

[@glennbabic5954]

Gravity is BARELY less at the cruising altitude of an airliner, not even as high as the ISS, the air pressure is less because there is less atmosphere pushing down from above you.

[@JonPMeyer]

That was an outstanding explanation! Thank you for not trying to simplify everything to the point at which your explanations become incorrect. I have been trying to understand how to correctly explain the warming effect of certain gases for many years and I have NEVER heard anyone explain the “altitude” issue like you did. Also, I really appreciate the explanation of stratospheric cooling and why that prediction supports the human-caused climate change story. There is quite a bit of good science content on KZbin these days, but your channel is among a very small number of really great ones!

[@buddymccloskey2809]

See the follow up in "Who Broke the Greenhouse?" soon. The stratosphere CO2 is even less than the near 0 effect of CO2 below 10,000'.

[@grindupBaker]

@@buddymccloskey2809 You typed drivel.

[@oliverheaviside2539]

@@grindupBaker Very impressive argument. Dummass.

[@Mass-jab-death-2025]

I’m more afraid of gravity change. Since the widespread availability of backyard trampolines started in the late 60s the earth’s rotation has slowly been knocked out of kilter. It is now becoming critical, countless billions are being spent of so called ‘climate change” yet this more pressing pending disaster is largely ignored. I can solve this problem once and for all using strategically placed counter weights on springs at strategic gravity hotspots ( namely my backyard) and I can do all this for a cool 2.5 billion dollars. Don’t wait for the world to end with us all either shooting off into space of being crushed into the ground. Send your tax deductible donation to the “Harvest the gullible fools Institute”. We are also hiring the services of Santa Clause and the Easter Bunny to solve Climate Change. Santa is going to fly his slay around during his off season and the Easter Bunny will accompany him sprinkling the clouds with left over chocolate which has been finely powdered. This will stain the clouds brown and block the sun ending the dreaded warming that we are assured will one day cause sea levels to rise somehow. This can be done for the bargain price of 1.25 billion ! So what are you waiting for Send your tax deductible donation to the “Harvest the gullible fools Institute” NOW or they may be no tomorrow !

[@lrvogt1257]

@@oliverheaviside2539 : He's not wrong.

[@crawkn]

I'm very pleased to learn that Sabine isn't one of those (typically) insecure scientists who are afraid to ever admit to having misunderstood something. Nobody, no matter how well educated and / or brilliant, has never been confused by anything in this exceedingly complex universe. _Maybe_ underlying it all are some simple rules, as some suggest, but the myriad layers of chaos and emergent properties make it on the whole quite confounding. What should be notable is not that scientists are sometimes wrong, but that they are frequently right.

[@zen1647]

Yes! Admitting that you don't fully understand something is usually a sign of intelligence, not the opposite.

[@DavidHRyall]

They should actually be wrong more than they are right. A 90% failure rate is healthy.

[@seeyoucu]

I appreciate that greatly.

[@crawkn]

@@DavidHRyall of course it's part of the experimental process, but I'm more referring to what they consider their established knowledge base. In this case, the greenhouse effect is a very mature (although still expanding) science with a lot of popular exposure, so I'm sure any scientist worth their salt probably _thinks_ they understand it.

[@ghytd766]

Sabine is extremely confident in herself, allowing herself to admit failures. And imo, her confidence is well deserved. She's legit.

[@oystercatcher943]

This was amazing but I need to watch it again to fully get it - if I can. Though I'm pretty sure pressure and density doesn't reduce with altitude because gravity is less higher up, its because there is less gas pushing down from above the further up you go

[@samuellowekey9271]

Yes, actually a combination of the two(I know that you understand that). I think that the effect of the reduction in gravity with altitude on atmospheric pressure is tiny compared to the effects of the reduction in gas pushing down on the atmosphere below with altitude.

[@EeezyNoow]

@@samuellowekey9271 Gravity has a part to play in the diurnal atmospheric temperature. During the day the increased temperature raises the centre of mass of the entire atmospheric column by around 100m - raising its potential energy. During the night, as the temperature reduces, the centre of mass descends back by that 100m thereby compressing the air and raising its temperature by compression/gravity alone. This is the diurnal squeezing effect which is substantial. But do any of the climate models take it into account?

[@MrMichaelFire]

Of course, just like gravity is essentially the same in the space station as on earth.... I don't need to elaborate.

[@karolinahagegard]

Try and dive 4m down in water. The pressure increase is already immense!... Is it because the gravity is stronger, down there? 😏 Of course not. It's because of the weight of the water above you. Same with air, only it weighs less so you need bigger differences in altitude to feel the difference in pressure. I'm pretty sure the Earth's atmosphere is close enough to the Earth for the gravity to be about equal throughout it. If Earth is the size of a football, the atmosphere is 1 mm thick, something like that.

[@karolinahagegard]

@@EeezyNoow , in nighttime, the center of mass of the atmosphere sinks back 100m, thus compressing the air, thus INCREASING ITS TEMPERATURE?!... No no no, the air reduces in volume by night BECAUSE the temperature is lower. Therefore, this "compression" does not increase its temperature again! The temperature of a gas only increases if compressed by an outer force, raising its pressure. Not if it just relaxes into a smaller volume because it gets cooler, and at a constant pressure, like in the case of nighttime. It's the ideal gas law: PV = nRT When T sinks PV must decrease. In this case, it's V that decreases, and P stays the same. (Atmospheric pressure is the same in daytime and nighttime, on average.)

[@johnsears712]

Another suggestion for a future presentation would be the removal of CO2 from the atmosphere during the life cycle of the whale.

[@manoo422]

You forgot to mention the warming effect from CO2 is a log scale i.e its effect is ever diminishing. You have to keep doubling the CO2 level just to get the same heating effect...

[@manoo422]

@@stapleman007 What was the challenge...!

[@alterego-bg8gs]

I have a PhD in AMO physics and you just blew my mind. Thank you for this video! I feel when it comes to global warming there is a coverage gap between super-simplified explanations and full-blown climate models. I really appreciate your video explaining it layer by layer.

[@Lexoka]

And that gap leaves a lot of room for CC-denying bullshit to slip through.

[@JohnSmith-is1qc]

it's not bs when party X claims something is true, when it contradicts known physics... and then appeals to complicated "models" as excuse to produce the insight how the stuff works from physics point of view... ie upper-atmosphere cooling is dead obvious anyone who has looked upon planck's law and checked the empirical results of co2 measurements from 1905 and onwards... theres plenty of older climate stuff online that shows this parody... claiming after the fact you were caught pants down that you knew you have pants down... despite history showing people were adamant pants are up... is bad science itself... denying part might be elsewhere than you think

[@mathoph26]

So give us an equation please ! I have also a phd in particles scattering (Mie theory etc)

[@user-ti5rb1mx5x]

​@Lexoka no one really denies CC, it's just not an emergency. It's gotten an average of 1 degree warmer since the Industrial Revolution.

[@BerndFelsche]

@@user-ti5rb1mx5x You mean the LIA? ;-)

[@raywoodward1967]

I did my undergraduate honours degree in physics and geophysics. I'm really impressed by how well both the broad principles and the intrinsic complexities of atmospheric physics were explained. I've had numerous requests to explain global warming and whether or not it's all a hoax being pulled by greedy scientists eager to pad their research grants so they can drink champagne and live the high life in their luxurious 5 star ivory tower penthouses or is it real and being played down by billion dollar industrial lobbies keen to ensure that they can continue to make huge profits from the extraction and sale of hydrocarbons. I'll point them to this video from now on (except those who insist the world is flat or that the moon landings were all fake - unfortunately they seem to live in another Universe entirely and it's one I don't really understand).

[@schmetterling4477]

Why are you lying about your education? ;-)

[@johnl5316]

see Princeton Prof of Physics, William Happer & MIT Prof of Atmospheric Physics, Richard Lindzen

[@user-yq2bp1ho3n]

the moon landings never happened, and father xmas ain't real either.

[@anticorncob6]

It's the latter scenario. The former doesn't make sense.

[@misterserious3522]

If politicians and elites say they can spend YOUR money and rights and make it ok, then its a hoax If they were willing to spend their own money and live like the rest of the public must, then it might be real. Guess which is the current situation.

[@send2gl]

Fascinating, followed your reasoning but confused by the science. Interesting that you admit to misunderstanding a theory in your younger days, science always evolves, once upon a time the Sun circled the Earth. Sadly nowadays many refuse to change opinions when further data evolves.

[@tomboyd7109]

Thank you. I now understand the phenomena more thoroughly. I will have to play it a couple more times to be comfortable with my understanding. I just noticed that several other commenters said similar things. This means that your presentation is just about the level that I need. Thank you again.

[@annaclarafenyo8185]

Do not watch this video, it is wrong from start to finish. The mechanism of greenhouse gas heating is very simple--- extra CO2 scatters infrared light, leading to a longer path-length to escape. The mechanism is photon-by-photon, the mean-free-path to scattering is reduced with extra CO2, and so there is NO INTERFERENCE between wavelengths, there are NO COMPLICATIONS, and you can calculate the extra heating simply on the back on an envelope (if you are a physicist) without any problem. Sabine is not a climate scientist, and it shows.

[@davidvaccari2321]

Whoops! Sabine, you made a little mistake at 7:05. The atmospheric pressure decreases with altitude almost entirely because as you go up, there is less weight above you to push down. It's not because gravity decreases by r-squared. Yes gravity does decrease, but that is a much smaller contributor to the effect. This doesn't change your overall explanation. Thanks.

[@kevpatguiriot]

👍

[@SpectatorAlius]

But remember that the "weight above you to push down" is itself dependent on gravity. Otherwise there would be *no* weight.

[@andrewwade1651]

@@SpectatorAlius Sure, but over the 50 or so km relevant to the greenhouse effect g doesn't vary much and the pressure very much does. In a hypothetical flat Earth where g doesn't vary with height you would still get the approximately exponential drop-off of atmospheric pressure with height. (Assume this hypothetical Earth is accelerating upwards to provide gravity, and has walls on the edges to keep the atmosphere in.)

[@boohoo746]

she needed to make that mistake so she could poke fun at the flat earthers. Ph Ds are the most arrogant (and most frequently wrong) people on the planet.

[@DrDeuteron]

if you believe in traceless strain tensors, the weaker gravity in the longitudinal direction is entirely canceled by the "focusing" (converging radial gravity lines-of-force) in the two transverse directions.

[@bobloblaw10001]

Carl Sagan said it better: the greenhouse anology isn't perfect but it's good enough to turn understanding to action. Carbon dioxide traps heat, and we need to stop increasing its concentration in the atmosphere.

[@grindupBaker]

Hi Bob.

[@davidrussell8927]

There is nothing that shows how carbon dioxide could measurably change the temperature of Earth's surface.

[@bobloblaw10001]

@David Russell there is nothing that shows that David Russell is a sincere person who knows what he is talking about

[@davidrussell8927]

@@bobloblaw10001 Thank you for confirming that you have nothing that shows or explains how carbon dioxide could measurably change the temperature of Earth's surface.

[@thomaskilburn3111]

at 76 years of age. i enjoy your shows. i do understand what you are talking about. i only have a fifth grade education because the teachers in Plains high school, Plains,Georgia USA thought that it was no use to teach a share cropper. I got a education in electronics , mechanics and poly chemicals after Vietnam. I showed thoes people.

[@grindupBaker]

Good on you mate. I'm 77 pushing 78. Are us Boomers the Cat's Pajamas or what?

[@kerryatkins3656]

God bless you fellow Vietnam, veteran and thank you for your service!

[@garbonomics]

Fantastic video even if it’s incomplete. The earths climate system is so complex that this is still not the full story. However with all that said there are a few thing not related to the physics of it all which are also relevant. Mainly the fact that we not only want a warmer climate but more co2. Co2 of course being plant food. This been an enormous boon to crop production and has caused an expansion in greening of the planet. That’s right more plants, which of course we want! Also cold temperatures are actually NOT beneficial to human life. We want a warmer planet which is conducive to a better life for people everywhere. Similar to the medieval warm period that ended at the beginning of the little ice age. Form 1350 or so to 1850 the earths temperature cooled. This rapid drop in world temperature lead to a decline in human populations, famine and a worse quality of life for everyone. This warming period has been a blessing for everyone around today even if the climate fanatics don’t want to admit it. This is the best time to be alive. And it’s partly because of a warmer climate. 🤭

[@MeppyMan]

Oh boy… bracing myself for the comments that will be coming.

[@PhysicsLaure]

Summer is coming!

[@MeppyMan]

@@PhysicsLaure summer is already here. Weirdly we don’t all live in the northern hemisphere 🤣

[@PhysicsLaure]

@@MeppyMan Haha! I meant it as a reference to climate change. But your point, I hadn't thought about that :p

[@MeppyMan]

@@PhysicsLaure I figured. And my jibe was in good humour my northern friend.

[@PhysicsLaure]

@@MeppyMan All good! Enjoy your Summer days 😉😙

[@DavidPSchmidt]

Thank you for the excellent explanation. I would like to offer what I believe is one small correction. The reduction of static pressure in the atmosphere at increasing height is due to the fact that as altitude increases, the air is supporting the weight of less air mass above. Even without the inverse r-squared variation of gravity, the pressure in the air must decrease with increasing altitude.

[@PhilippeLeick]

Thank you to Sabine for the excellent video and to David for the small correction. The decrease of gravity within the relevant parts of the atmosphere, which has a "thickness" of about 100 km, is also quite small, as these ~ 100 km are not much compared to the radius of earth (slightly more than 6350 km). To summarize in a humorous way: Even a flat earth would have an atmosphere that becomes less dense and colder at higher altitudes. At least as long as we don't think too much about what happens to the atmosphere near the edge of the disc. That being said, the (nearly) spherical shape of the earth is still important for the greenhouse effect.

[@guymiklos9245]

The distinction David (and many others below) seems to be making is between direct gravitational "pull" on molecules and cumulative "pull" - the latter emerging as pressure increasing with depth. Both are due to gravity.

[@Isawwhatyoudid]

It would take way too much effort on part of your average CC denier to watch and understand this.

[@grindupBaker]

Yes, 6 years ago I typed a comprehensive description of GHE in 3 GoogleyTubes comments parts because it's beyond the GoogleyTubes length limit and got one reply from a bloke who said it was very interesting and he'd read it repeatedly until he grasped it, never heard from him again though, and a reply of "LOL, you really expect anybody to read all that ? LOL" He was right of course, 1 reply in 6 years (I posted it 30-40 times before I stopped bothering). Got one piece of information reply ("thermal relaxation") on RealClimate where 90% of the bods are interested in science rather than money.

[@davidrussell8927]

Nobody denies climate change, but the "greenhouse effect" is ridiculous.

[@2adamast]

7:00 The gravitational force is as good as constant between 0 and 100 km altitude (6400 to 6500 km for the inverse square calculation), so the inverse square law doesn't matter unless you have a fight with flat earthers.

[@cbongiova]

All these climate models always start in very late 1970’s or 1980’s because this was a colder climate for a number of years. If you expanded that over 100 years you would see all these models would fall apart. Also water has a lot bigger affect on climate than CO2 and is a vastly greater amount of the atmosphere (a couple percentages vs 0.04% which is 50-100x more water vapor than CO2). So if water vapor is such a large affect why are we going insane about CO2?? Because this is a by product of a lots of industries and thus there’s money for it. Stop politicizing this issue, continue to improve our models and stop corrupting and changing the data (a lot of data was change in late 1990’s early 2000’s) to show warming where there is none. Do these things and bring science back into this discussion instead of making a mockery of it much like the COVID debacle.

[@kevpatguiriot]

.

[@LNJ1188]

Very well done. The one thing I would like to see is a comparison of the effect of CO2 to all the other variables that effect the temperature. My simple understanding is that CO2 is a very small effect and the other natural variables are much larger. So from my point of view it looks like CO2 effect is lost in the noise.

[@kevpatguiriot]

.

[@wassabied]

i didnt understand most of it. appreciate the effort thoough

[@RichardDonin]

I’m very impressed with all your skills and talents - physicist, lecturer, writer, science communicator (like Carl Sagan), and to top it off, a savvy marketeer. Congratulations!

[@gregmellott5715]

KIS helps Sane thinking.

[@robr177]

You forgot Singer/Songwriter: kzbin.info/door/PtRwW9i43BXbCRQa7BJaiA

[@tango_uniform]

@@RWin-fp5jn Much of what you say is correct. However, the earth is greener in 2019 than 20 years earlier. Check MODIS data at NASA. Increased CO2 is due to more plant matter, not less. None of the supposedly learned "scientists" can explain the causes of every other warming and cooling period in history that occurred before humans walked the planet. But THIS one... THIS one is definitely anthropomorphic. Because it's convenient from a hysterical perspective. During the last glacial maximum, temperatures were only a couple of degrees lower than now. Before the sheeple are convinced that the logical thing to do is cool the planet, we might ask the people who now live where the last glaciers were. I live where the Columbia River lobe of the Cordilleran ice sheet was. OK, I just took a poll of my household. We all vote not to cool the planet.

[@Thomas..Anderson]

She also sings. Check her other channel.

[@cdl0]

About thirty years ago in the early 1990s, I attended a colloquium given by a climate scientist about this subject. At the end of the presentation I asked exactly the question about the broad, saturated absorption bands of water versus the narrow band of carbon dioxide, which, sadly, our guest speaker could not answer, and I have wondered about ever since. So, now we know, and I am still alive.

[@grindupBaker]

You can plainly see H2O gas radiating from average ~2 km above surface on any FTIR from space (since 1964 when they started with IRIS-A on Nimbus 1). You see the 10-13 microns that goes up in the land surface "atmospheric window". You see the huge CO2 notch that cuts far higher (far colder, far less radiated) than the King Water Vapour in the lowest ~2 km above surface. This is why non Water Vapour are called the "well-mixed" ones by scientists, because they go very high without condensing & thus losing most of their LWR power (clouds water drops & ice crystals do have LWR effect into them about 10 microns of course but it's far more powerful when the molecules are spread out as a gas because their molecule pals don't crowd them out). University Chicago MODTRAN has a Sahara Desert sample 1968 FTIR & there are others around like examples of these measured FTIR power flux vs wave-length spectra (for western tropical Pacific Ocean, Sahara Desert, Antarctica & southern Iraq) can be seen at kzbin.info/www/bejne/haDKaGCBhNmje6M at 18:07 FTIR power flux vs wave-length spectra recorded by the IRIS Infra-Red Interferometer Spectrometer instruments on the Nimbus-1 (1964 - 1964), Nimbus-2 (1966 - 1969), Nimbus-3 (1969 - 1972) satellites show which wave-lengths of LWR heading to space past the satellite. MODTRAN is this: Software Description MODTRAN - MODerate spectral resolution atmospheric TRANSsmittance algorithm and computer model, developed by AFRL/VSBT in collaboration with Spectral Sciences, Inc. MODTRAN4 has been available to the public since Jan 2000. It remains the state-of-the-art atmospheric band model radiation transport model. PATENT: The Air Force Research Lab, Space Vehicles Directorate, in collaboration with Spectral Sciences, Inc., is pleased to continue the release of MODTRAN4 as a fully UNCLASSIFIED atmospheric radiative transfer code and algorithm. MODTRAN4 follows the prior releases of LOWTRAN (now fully obsolete) and the earlier MODTRAN3 series. MODTRAN4 has been awarded a U.S. Patent, # 5,884,226; 16 March 1999. FEE: Access to MODTRAN4 requires that a new Non-Disclosure Agreement (NDA) be signed and a fee paid. Source code, data files and PC-executables are all on CD-Rom and distributed by the ONTAR Corporation for the Air Force Research Laboratories (AFRL). The fee payment instructions will be supplied upon receipt of the signed NDA. Because the moderate fee (~$300) includes user-support, all receiving parties (Universities, Corporations, and Government Agencies) are subject to the assessment. Furthermore, the NDA term "CORPORATION" only denotes an individual research group. If any single CORPORATION has disparate research groups, each using MODTRAN4 in a different capacity, then the fee applies separately to each group. To do otherwise (distribute across research applications) constitutes secondary re-distribution, which must be individually negotiated with the AIR FORCE. DESCRIPTION: The Moderate Resolution Transmittance (MODTRAN) Code calculates atmospheric transmittance and radiance for frequencies from 0 to 50,000 cm-1 at moderate spectral resolution, primarily 2 cm-1 (20 cm-1 in the UV). The original development of MODTRAN was driven by a need for higher spectral resolution and greater accuracy than that provided by the LOWTRAN series of band model algorithms. Except for its molecular band model parameterization, MODTRAN adopts all the LOWTRAN 7 capabilities, including spherical refractive geometry, solar and lunar source functions, and scattering (Rayleigh, Mie, single and multiple), and default profiles (gases, aerosols, clouds, fogs, and rain). CURRENT CAPABILITIES: The current release is MODTRAN4, version 3.1. This version number connotes the additions of some errata and new physics since MODTRAN4 was first patented and released. The major developments in MODTRAN4 are the implementation of a correlated-k algorithm (references below) which facilitates accurate calculation of multiple scattering. This essentially permits MODTRAN4 to act as a 'true Beer-Lambert' radiative transfer code, with attenuation/layer now having a physical meaning. More accurate transmittance and radiance calculations will greatly facilitate the analysis of hyperspectral imaging data. The other major addition to MODTRAN has been to provide sets of Bi-directional Radiance Distribution Functions (BRDFs) that permit the surface scattering to be other than Lambertian. The combination of correlated-K and BRDFs has greatly improved the scattering accuracy, as has the implementation of azimuthal asymmetries.

[@douginorlando6260]

The lack of understanding by the climate scientist proves it’s not based on science. We do know the WEF power cartel is using the fear of climate change to steal farms from the farmers who worked their land for generations

[@hg2.]

Is co2 glorified humidity?

[@dilvishpa5776]

Water vapor is a more significant greenhouse contributor than is CO2. I am with you. I have heard 50 years of gloom and doom scenarios, and none have been realized. Were any of then true,I would be dead three times over. CO2 is a greenhouse gas, but as numerous physicists have comment (Bill Happer and Tyson Freeman among them) it’s contribution is already near its maximum, and will not contribute significantly in the future. The “shoulder” argument Sabine references is bogus. Vibrational molecular energy absorption is quantized, so there are no “soft shoulders”, and a few degrees of temperature increase will widen the CO2 absorption range, but at 273K that effect will be insignificant.

[@dilvishpa5776]

@@hg2. No.

[@Carmine207]

This is terrific Sabine - thanks so much for all you do. I get into these conversations with the deniers and I keep telling them - How do we know that it comes from human activity? Here's the thing - we can fingerprint the isotopes of carbon. We have a very good data set about all the natural processes, how much carbon comes from volcanos, from forests, from chimneys and tailpipes, how much is captured and released by the oceans and so on. Plus we have very accurate data about atmospheric concentrations going back hundreds of thousands of years. Natural processes cannot explain the extra CO2 that we are seeing, and that rise began at the same time as the industrial revolution. We know with a high degree of certainty what is normal for this planet when we look at the hard data in ice cores and sediments from glacial epochs during the last 4 million years. The current climate change direction is unprecedented. For the last 4 million years the pattern has been extremely stable - glacial - interglacial - glacial - interglacial - repeatedly. We have empiric data, hard inarguable facts, reams and reams of them - the CO2 during a glacial epoch is consistently at 180 ppm. The interglacials are consistently at 280 ppm. Think about that - 100 ppm CO2 makes the difference between glaciation and an interglacial. Insanely small variances in a minor trace gas have astonishgly huge and global impact on climate. Additionally, CO2 levels, temperature and methane levels are coupled. That means that whatever happens to one happens to all three. It doesn't matter which one goes up first. Typically the Milankovitch cycles trigger an initial rise in temps, but whenever one rises, the others will follow within specific lag times. We see that actually happening in real time everywhere we look on the planet today. We can calculate the total CO2 being exchanged up and down from natural processes globally. We can see the evidence of extra CO2 that is not accounted for from anything natural. We can take measurements that tell us how much heat and how much CO2 is in the oceans and what is being left in the atmosphere is from us. In any case thanks for this video. I will include it into my reference list. 🙂

[@PeterBaumgart1a]

Minor nitpick about the pressure vs altitude in the atmosphere, somewhere around 6:50 : The inverse square law is not needed for this. Compressibility of gases with a constant g is enough to give the exponential decrease with altitude (as opposed to linearity under water, which is essentially incompressible).

[@grindupBaker]

Minor nitpick about the incomprehensibility. I think that "is essentially incomprehensible" S.B. "is essentially incompressible" but still it can't be all that incomprehensible otherwise I wouldn't have compressed it so easily. At kzbin.info/www/bejne/l3uTn3mHnLd0prs

[@PeterBaumgart1a]

@@grindupBaker autocorrect, meant to say incompressible of course... Yeah, compared to gases water is essentially incompressible. But still somewhat compressible of course as we know. Excellent link. Thanks! 😂

[@grindupBaker]

@@PeterBaumgart1a I recall about 0.5 degrees at the sea bed for adiabatic heating when I looked at it in 2014. Difference between measured temperature and Potential Temperature theta with the compression heating removed (oceanographers must adjust for it). Don't quote me on the 0.5 degrees at the sea bed from my memory though, no money-back guarantee.

[@andrewgregg5873]

Amazing video. My father and I are both STEM masters, he is (or at least was, we haven't discussed the topic in a while and he has changed views over time before) a climate change denier. He always dropped the point about how the radiation is fully absorbed early on, the first time you say rhetorically "so it's all a hoax?", which is very easily verifiable and bunks the first model you go over and stumped me for a long time. Trying to find clear scientific info on the topic took a lot of research and eventually I found a paper on radiative forcing (referenced by the Copenhagen papers that I read in their entirety) which I believe is the 2nd point where you get to the rhetorical "so isn't it all a hoax then?". I found the same issues as you. It's so hard to find good science info to actually understand amidst all the political content. I don't think the majority of climate supporters even understand the first explanation. For them it's a political issue and the science is "Just trust the experts". I have always seen holes in the flawed explanations you call out and have kind of been agnostic as to whether the cause is CO2 or not, to me the correlation was unproven and I was supporting climate measures out of more of a pascal's wager: better to take measures and be wrong than to not take measures and be wrong. The correlation is certainly there. It never sat well with me though, and every time I ever brought up doubts, I always get appeals to authority ("trust me the experts know way more than you just trust them") or ad hominem attacks ("how can you not care about the Earth???") when I just wanted to learn. Over the last 12 years I have asked many stem people in real life, made an r/askscience thread asking for clarification on how radiative forcing actually translates to warming, and never gotten a satisfactory answer (but a ton of attacks for daring to question what people are politically invested in for sure). In my experience, the percentage of people who can give the greenhouse explanation is maybe 50%, the number who know about radiative forcing is

[@stuartd9741]

kzbin.info/www/bejne/ZpWYZqGmZZaUhrc

[@kirklaird8345]

One thing you should keep in mind before you go on the attack. No one who knows science discredits or ignores the fact that CO2 is a greenhouse gas. The real questions of importance are these: 1) Will the warming be significant? Sabine's presentation explains why we should expect some warming from CO2, all other things being equal, but she doesn't provide an estimate of the amount of the effect. 2) Will the warming be good or bad? There is plenty of evidence that additional CO2 and warming result in a greening of the planet and higher crop yields,. 3) Are there other factors such as cloud formation physics that are involved that we do not understand enough to draw realistic conclusions about anthropogenic CO2 and 4) Can we trust the global alarmists? They've been shouting "The sky is falling and the seas are rising rapidly and accelerating" for the last 30 years. (E.g. the Maldives were supposed to have been submerged by 2018 according to a prediction by Noel Brown, head of the UN's Environmental Office in New York in 1988.) Yet according to tide gauge data from around the world, the average sea level rise along the coasts has been about 1.8mm/yr for more than 100 years. If there has been any acceleration it is trivial. JR Houston (2021) found an acceleration of .0128mm/yr/yr - which is indeed trivial.

[@doctordapp]

I have studied it a lot as well like you, but without any masters degree. And I don't dispute that our added CO2 does change it a bit. But I am called denier, like your father for the questions I am asking. My questions are plain and simple.. - how much does it actually change the temperature on the earth? No calculations are shown ever! - will that be a problem? I don't see any problem in the temperature rising a fraction, as well if you would purely calculate the radiative forcing, my calculations would end up around 0,7°C for a Co2 doubling. I would like to hear your opinion on this as someone with a masters degree...

[@wuokawuoka]

@@doctordapp Well, in my region, vintners are happy to cultivate kinds of grape that need more sun and warmth than ever before (that is a couple of hundreds of years, just to be clear) producing better wine. Nice, isn't it? Not really, in the Alps, skiing in winter can only take place in higher altitude, with lower altitude facilities already going out of business. Glaciers in the Alps shrink, rainfall patterns change to the truly erratic but insufficient side, groundwater levels sink, twisters are a thing now and bugs only found far south a decade ago are the new normal. All in all, there is so much more energy in the atmosphere, ground dries up and now common species of trees are already in decline. Mankind set free CO2 that has been sequestered over millions of years in a span of a mere 100 years. We already see the effects. There is no known precedent of CO2 levels rising this sharply in earths history (levels, yes. But speed of change, no). There is no known natural mechanism to catch that much CO2 in such a short period of time we need to keep our civilization (and economy) going the same way as today.

[@doctordapp]

@@wuokawuoka glaciers in the alps shrink and grow. If you look at newspapers from the 1930's you see exactly the same conclusions. After that the glaciers where growing again until the late 70s. So I am still not convinced that all this temperature rise is caused by us. The last market on the thames was in 1814.how was it better then? They can declare the current rise with Co2, but the can't explain the rise in the 30s with the same story. So the story doesn't compile to logic here....

[@michaelcornish2299]

Excellent, I tell students that we 'tell them lies or simplify things - you chose the turn of phrase'' and as they go through their education the we tell them 'slightly lesser lies or add more detail - again choose your turn of phrase' because the truth is often complicated. When they ask about quantum mechanics and I try to explain it to them they understand why we don't tell them about it earlier.

[@Chocwish]

Dunning Kruger effect?

[@MrTkharris]

Yea, lies-to-children is an interesting educational concept explored in some depth in _The Collapse of Chaos_ [1994]. It has roots in Wittgenstein's Ladder. He said something to the effect that we give students ladders made of lies that they should throw away, but not before first climbing up them.

[@PeterBaumgart1a]

Well, simplifications, even gross ones, are not necessarily "lies." Lying implies malice or undue advantage to the lier.

[@maythesciencebewithyou]

It's not really lies. Every good teacher tells their students that they are explaining a simplified model when they do so. What you need to teach a student first is what a model is and why we work with models. Things are complicated, so of course you can't just jump into trying to understad them right away or learn the most detailed models we have from the get go. You have to get there slowly, step by step. And if you are just a normal person who isn't even interested in learning this kind of stuff, and most people aren't interested in learning science, then you wouldn't want to learn these details. Most people want simple answers. And even the simple answers are too much for most people. In these comments you always find people bitching about school and why they didn't teach this stuff to them in school. Well, this is infotainment and the actual info here simply goes beyond the scope of school. Most of these people would have hated this subject if they actually had to properly understand it and explain it in an exam. Even if some of them are science buffs who like this stuff, most other highschool students would have hated this. This stuff is what university is for. If highschool taught everything, then you wouldn't need to go to uni. And a university student doesn't needs to learn every subject in all detail. A biologist has to learn physics, but they don't need it to the same level as a physicist. And a physicist who specializes in one field doesn't have to know every detail of another field. It's not possible to be an expert in everything. Some stuff we know in better detail, but most of what we know is superficial knowledge on a subject. This video went into more detail, then the dumbed down stuff most people hear, but even this video doesn't explain every detail. Most viewers here would have hated it if she made a full boring lecture and even more so if there was an exam at the end. Most ironic are the people here who don't realize, that Sabine read a scientific textbook from a climate scientist to get this knowledge and act like she presented something controversial and in support of climate change denial.

[@peterblair6489]

I remember my chemistry teacher said that a lot. Lol I think lie is a bit harsh. We can't handle the truth.

[@PeterAGW]

Really glad to see a video that explains this. But there's an error (which doesn't really affect the fundamental point) where you say air pressure decreases with height primarily because gravity weakens - gravity varies very little over the thickness of the atmosphere - pressure decreases with height mainly because each layer of the atmosphere is holding up all of the atmosphere above it, so pressure must be highest at the surface and then it decreases to zero out to space, roughly exponentially with height. The next video can explain why temperature really decreases with height up to the stratosphere- it's not just due to pressure decreasing - fun physics with radiative-convective equilibrium etc. ;-)

[@kevpatguiriot]

👍

[@davidmillar7594]

Thank you Sabine. I appreciated your explanation. Regrettably, I have a science degree. The 'part of the real' explanationwill be lost on the majority who vote for poiticians who work in sound 'bites' and three word slogans.

[@Hickalum]

It’s lost on me too … I can’t see how one “wriggling” CO2 molecule can heat up the surrounding 10,000 N2 and O2 molecules unless the CO2 molecule is at some astronomical temperature.

[@grindupBaker]

​ @Hickalum LOL. It's actually fine for you to point out that you have a mediocre science education and mediocre brain for physical science and its logical thought processes, and have zero interest in the physics under discussion by a few of us, and have never thought about it in the slightest, let alone done the trivial calculations, simply because it means you are "ordinary, normal, ho hum human". You should proceed with life enjoying yourself as however and occasionally informing any audience that you are utterly clueless about this, or about that, or about the other thing, and you always will be because ... you know ... mediocre science education and mediocre brain for physical science and its logical thought processes, and have zero interest. I expect everybody is "bone idle lazy" about things that don't interest them in the slightest, I've completely stopped washing dishes & cutlery 6 years ago. Bone idle lazy. Dunno what's going on today. I usually point out to a lazy, babbling, total half wit that it's "a lazy, babbling, total half wit" so that it'll know that valuable information but this morning I'm massively relaxed & contented, almost comatose, probably just random body, diet & sleep ups & downs. I've gpme super mellow & laissez faire temporarily. What's that all about. Anyway, for anybody who IS interested in science skimming down the next few decades: ------------ 2.7 billion molecule collisions per second (8 billion in the lower, warmer, portion of the air). GHG molecule absorbs 1.8 photons per second so it absorbs a photon and then does 1 billion collisions, and all the N2 & O2 molecules do 1 billion collisions with each other. GHG molecule also manufactures & emits 1.8 photons per second, followed by another 1 billion collisions for all the air molecules, which are all moving at the speed of a commercial passenger aircraft at about 15 degrees and are VERY close together so PLENTY O' COLLISONS at 400 miles per hour sort of speed. All radiation up from Earth's surface is made by molecules that weight 10 grammes (1/3rd ounce, an eye dropper of water) over each square metre but the IRRELEVANT H2O & CO2 molecules above the square metre don't weigh 1/3rd ounce, they weigh 10.3 tonnes, the H2O gas molecules weigh 26 kilogrammes, the CO2 molecules weigh 6.7 kilogrammes. The "emits 1.8 photons per second" (1 photon per billion molecule collisions) above calculates to 1,500 times as much radiation in 1 second as all of the Sun's radiation Earth gets in 1 second. The LWR production & absorption in the air is SUPER-MASSIVE and the molecule collisions in the air is SUPER-HYPER-DUPER-HYPER-MASSIVE. I calculated all on the sofa with mugs of coffee, paper, pen & calculator in just 2 hours. Utterly trivial calculations from the known Molar quantities and thermal relaxation rates, and how far LWR travels through water. Why am I so mellow this morning? Must be the remnants of Hurricane Whatshername petered out in Ontario and it's a sunny morning.

[@sandman0123]

Another great video! People just want simple answers but that's very rarely, how things work, in real life!

[@Maganyos]

To err is human, to admit it is humility, to share it is wisdom. Thank you Sabine - this only increases my respect for you.

[@grindupBaker]

I'm sorry about that huge dent in the rear fender of your car. That'll just buff right out you know. Splash some paint on.

[@VideosYTJuan]

But Sabina, are we going to die if Countries don't stop producing CO2? Do we really need to stop using fossil fuels?

[@seltonk5136]

Busty babe

[@helgefan8994]

At 7:03 Sabine suggests that the force of gravity decreasing with altitude is responsible for air pressure getting lower with altitude, but that is wrong. Over those 100 km air pressure goes from 1 bar to almost 0, whereas the force of gravity is just 3% lower than on the ground. Instead air is less dense up there because there‘s less air above it pushing down on it.

[@Merakis100]

Wow - I can honestly say that I understood something before you did now :) Glad your understanding is growing! This is a much more complete explanation of why we need to be a little more worried about our emissions. Thank you!

[@liam3284]

Thanks, a side interest in atmospheric science, taught me that most heat flow at the surface is caused by convective and latent processes. There is still a window by which infra-red radiation escapes, which is clear to see on frosty nights, as the surface cools quickly by radiation. There is also "back radiation" from the atmosphere above, known as downward longwave radiation (DLR) which can exceed 300watts/M^2. That is where some of the oppressive heat on hot, still nights originates from.

[@Bertie.athenaeum]

Thank you Professor Sabine. It was high time that such a video was released.

[@annaclarafenyo8185]

Why? Everything in this video is incorrect. Sabine is not an expert in climate science, and this video is a form of soft global warming denial, by incompetently rebutting global warming denier claims.

[@edwardgatey8301]

Great explanation. I had heard the term ‘radiative forcing’ used in this context. I think I’ve got a better grip on the idea now. Didn’t realize the stratosphere was cooling which forces infrared emission to higher altitude.

[@itsgottobesaid4269]

Does heat go from a cold body to a warm body? Which is cooler,the ocean(earth's surface) or the atmosphere?

[@edwardgatey8301]

@@itsgottobesaid4269 Review the “CO2 ditch”.

[@grindupBaker]

"If Earth didn't have an atmosphere ... -18 degrees" at 5:17 is rubbish because it's incomplete. If Earth kept its ocean then more like -150 degrees or -100 degrees (who cares, just a stupid waste of time) because ice & snow are more reflective of sunlight than trees so an atmosphere-less Ice Ball in space would be FAR colder than -18 degrees. If the water was stripped away as well as the air but present surface albedo of 0.88 was kept (because it's all theoretical total irrelevance) and using 0.88 for surface Emissivity also, then the average surface temperature would be about 278K (5 degrees). I'm presuming the -18 degrees works well enough with present Earth orbit for a surface of volcanic lava & ash, grey dust, same albedo & Emissivity as the Moon but Sabine was too lazy to say that.

[@zetacrucis681]

The solar spectrum peaks in the visible (green specifically) not in the infra-red as shown here 3:48. (It's also broader than the curve shows.) The V.O. describes it correctly (saying "it doesn't change all that much in the visible", implying that the visible range is bunched around the peak) but the graphic is wrong.

[@timhallas4275]

One of the key factors in Earth's absorption of solar radiation is cloud cover. This is another of those "balancing acts" that the climate does. More heat evaporates more sea water, which increases cloud cover, which in turn reflects more sunlight back into space, which cools the Earth. Clouds both absorb infrared radiation, and reflect solar radiation. I've looked at clouds from both sides now, from up and down, and still somehow I really don't know clouds at all.

[@johnl5316]

see Princeton Prof of Physics, William Happer & MIT Prof of Atmospheric Physics, Richard Lindzen

[@johnl5316]

see the research of Nir Shaviv on solar energy, clouds, and temperature

[@jacob.tudragens]

I see what you did there!🎶

[@timhallas4275]

@@jacob.tudragens yep.

[@aliensuperweapon]

I am amazed. This is the video that the world needs because this misunderstanding is probably more widespread than we could ever be aware of. Your alternative arrows illustration really puts it all together what you explained in detail during the video, it makes so much sense and adds a lot of good argumentation also for our own understanding. Than you so much for that! Some million more people have to see this.

[@ifbfmto9338]

I’m going to be completely honest……. I’m all for science education, and this video is pretty good, but I’m not sure if the general public needs to know, or is capable of understanding in any way, the subtle nuances and complexities of (exactly how) greenhouse gases cause warming It is more than sufficient for the public to know the basic point, that higher greenhouse gas concentrations leads to warming, and that therefore we will need to attempt to control greenhouse gas emissions as part of any effective climate strategy

[@derkyarik_7298]

​@@ifbfmto9338 I must recognise, your comment, give me to an dilemma: 1º True is needed, if not, mankind is only a farm in the hands of some 'special people'. And I , on science since 1980, point for true, for honesty, the roots of any, any, science. 2º Social science, tell us that most part of mankind,,,,,,,, to tell it on polite view, do not have science and true as its most high value,,,,,,,,,,, I hope you understand me. So, yes, probably you have reason, but if we do this way, all mankind should, always, be cheated, swindled and robbed, yesterday, with 'the big-bad sadam hussein and his big and numerous massive destruction weapons', on 2011, with 'the big H1N1 mortality for all planet',,,,,,,,, about COVID,,,, you have your minds, they are the best judge,,,,,,,,,,, since 2005, 'the bad green-house' is going to give Mediterranean sea to Madrid, to Paris, and New-York (And Gozila) destroyed (It is nice to see all disaster on this city, ¿There are no other in the universe?),,,,,,,,, and so, on,,,,, forever. But on the other side, I know (I am 62 years old, more knows the evil for age, than for being the evil) how mankind, ,,,,,,,, is. So, yes, I can no solve this dilemma. For me, I have my choice, work, study, hard, for the true, hard,,,,, But for most, the true, is ,,,,,,,,,, other thing. Ifbfmto,,,,,,,,,,,,,, your words are not vane,,,,,,,, history is this way, now, and in Roma.

[@tobiaszb]

Thank you, That needed some attention to grasp. I've got it.

[@DeElSendero]

You're a great teacher Professor Sabine! Always a pleasure to watch your videos!

[@Leschsmasher]

😆🤣😂

[@EhrisaiaOShannon]

Do more of your music, Sab!! It's fucking GLORIOUS!! I miss your crazy songs. 💜🤗💜

[@anthonycarbone3826]

The key part that you went over quickly is the Status Quo for the current Human Age. Since the beginning of time the levels of CO2 have been dropping with each subsequent Ice Age. The earth is still recovering from the latest Ice Age and mini Ice Age which happens to be the same time for the rise of humans during the last 10,000 years. This period of 10,000 years has seen both warming and cooling periods that either made our life easier or harder. It is the cooling part that made human life much more difficult or challenging during the past 10,000 years. Throw in the Milankovitch Cycle which has to do with how far the earths orbit is from the Sun together with the changing angle of the earths tilt toward the sun and the picture gets much more complicated. To sum this up the earth is in the temperate part of the Milankovitch Cycle and in a normal warming period coming out of the last Ice Age. The only worry is CO2 is increasing at the fastest rate seen in the weather record but then again it was close to record low levels too. The shelled sea life was absorbing too much of the CO2 in the atmosphere before humans started releasing all this stored CO2 from the ages past.

[@grindupBaker]

See I can pad the comments with C R A P too. Not just the AI sock puppets like @mrphysh I'm multi-talented and monolingual

[@fletchergull4825]

This video has taught me how dumb it is for me to have any sort of opinion on climate change at all considering I don't have any clue what it even is

[@nwogamesalert]

You share that fate with 99% of climate scientists, but you are more honest about it.

[@techcafe0]

@@nwogamesalert and just wtf makes you a climate expert, huh??

[@nwogamesalert]

@@techcafe0 I am not a climate expert, but pretty good at recognizing frauds and scams!

[@stapleman007]

@@nwogamesalert It's hard to get funding to study something we already can precisely model.

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Yes I'm also a living testimony of expert Mrs Jane. Mrs Jane has changed my financial status for the best all thanks to my aunty who introduced her to me

[@christopheraikman3446]

This video discusses temperature structure of the atmosphere as if it is controlled solely by radiative energy transfer. But convection (and conduction) are also heat-transfer mechanisms. If the infrared opacity of the atmosphere increases (because of increased CO2), stronger convection will occur (when the temperature gradient exceeds the adiabatic lapse rate). Surely this is happening, as evidenced by changes in atmospheric circulation.

[@anthonymathias1]

Very True. Every body talks about radiation only. Convection is also radiation. It leads to transfer of heat from higher temperatures to lower and there is air circulation trying to equilibrium. Nobody talks about the Kinetic theory of gas laws. Strange.

[@richardhole8429]

Between Sabine H. and KathyLovesPhysics I think the gender bias in physics needs a major adjustment.

[@stephenclarke9660]

Brilliant explanation, turns out I had misunderstood it as well. Many thanks for making this.

[@gefginn3699]

Great post Sabine. I'm glad you have the patience to gather all this information and package it nicely here. You are a trooper. So many variables would make me feel overwhelmed. 🤩

[@andrewpriest9403]

Really liked the video, big piece missing is the crucial feedback assumptions. As I understand it, CO2 provides this small amount of warming, but that is amplified by the most important greenhouse gas, water vapor. Water vapor provides 90~95% of the greenhouse effect. And is somehow sensitive to the small effect CO2 causes, and amplifies it. Walking through that would have been really helpful. Based on this explanation plus other sources, it seems that the warming troposphere is supposed to push more humidity into the stratosphere enough to drive that effect 3-4x more than what CO2 addition would have done at its own. In other words, CO2 concentration increase by itself would be a 0.5degC gain, but the water vapor feedback pushes it to 1.5~2degC. As I understand it, this water vapor feedback assumptions and data is the contentious topic among the intelligent debaters. Because its one of the key topics of debate, hearing another intelligent voice explaining the mechanism would have been nice.

[@yes-vy6bn]

this has been debunked by the paper "Strong cloud-circulation coupling explains weak trade cumulus feedback" published in nature "Our observational analyses render models with large positive feedbacks implausible and both support and explain at the process scale a weak trade cumulus feedback. Our findings thus refute an important line of evidence for a high climate sensitivity."

[@3rdPartyIntervener]

I always knew DiHydrogen Monoxide was hazardous to humans in liquid form, but I had no idea how deadly the gaseous vapour could be.

[@MrBallynally2]

Bah, humbug. And Sabine is wrong. Co2 cannot kinetically work in the way she explains it. It can only be active in particular narrow frequency bands. It cannot give its energy to H2o which is broad spectrum. As a tiny trace gas it cannot deal w much of the sun's energy, let alone give it to H2o. Its saturation point will be reached within a few seconds. It comes and goes quickly. It does not force or amplifies anything. This is a common misconception. Im afraid Sabine does not know enough and her assumptions are just that. Statements without proof, like so many others. It is easy to fall for her arguments but it breaks down on a fundamental level, mainly the properties of Co2 which are absent from this presentation..

[@tcbrit64]

@@MrBallynally2 The start of the video seemed wrong to me. A greenhouse gets warm because the incoming radiation warms the floor of the greenhouse and objects in it, which then warm the air inside, which can’t escape on account of the glass in the greenhouse walls and ceiling, so the air gets hot.

[@misterserious3522]

@@yes-vy6bn Safe, AND effective redux

[@john_hunter_]

Interesting that I haven't seen a proper explanation of the greenhouse effect until now.

[@grindupBaker]

Michel Van Biezen's is hugely detailed packed with related information but then fails at the crucial element. Still good related inof though.

[@enderwiggin1113]

Then you simply have not looked enough. There are books on it out there which are easy to find.

[@Socrates3001]

Thank you for treating me like an adult and actually explaining the effects of CO2. There are certain people in the world who don't know this about CO2 but would think that I am the idiot for wanting to understand how the atmosphere works.

[@pompeymonkey3271]

To get a complimentary perspective on how the atmosphere works, I highly recommend getting a gliding experience flight on a warm spring day. :)

[@sillysad3198]

as an adult you have most certaily noticed that it is not an explanation on multiple accounts, beginning with the UNDEFINED term "average surface temp"

[@tpog1]

If you want to know how things like these *really* work it means years of studying of high level physics. “CO2 makes the atmosphere trap more energy received from the sun which heats up the planet” is a perfectly good explanation, even for an adult.

[@CyVinci]

@@sillysad3198 what about that metric is hard for you to understand lmao

[@sillysad3198]

@@CyVinci the absense of definition? lyao?

[@buellterrier3596]

That animated figure at the end nailed it. All those diagrams with arrows in many books were all misleading! I admit, I also misunderstood the whole thing, and i’m supposed to be an environmental scientist! Thank you.

[@grindupBaker]

I complained (or tried to) on Realclimate July 2021 about all that crap everywhere about photons from the surface being "re-emitted" back to the surface, but Realclimate censored my complaint instead of posting it for discussion.

[@K3wlG33k]

​@@grindupBaker hmmm... somebody's trying to censor anything that may go against some kind of narrative I see, not quite sure what though. This is Galileo's history with the church all over again, albeit at a much more "tamed" and smaller scale. Nevertheless, still quite a concerning practice imo.

[@K3wlG33k]

@@syrious_kash8268 -_- you mean do the one practice that is the basis when it comes to EVERYTHING politically/legally/criminally/morally disconcerting? Why didn't I think of that?! 😯 I'm sorry I know I didn't make it too clear in my comment, but I was trying to be somewhat vague though still hint at the fact that I understand what's happening to those with a trained eye when I mentioned "censor that goes against...[a] narrative." I mean, that is an oddly specific phrasing, don't you think? I wanted to help others who may not have figured this out yet to start understanding these things for themselves. People who typically frequent these science-focused videos may/may not be well-informed of politics sometimes; I was/am one of them for certain things. Hence, I know how it's like learning these things from that position. So fair enough if you think I'm an idiot; I think so too. It's still a concerning practice that's rampant in many different facets of society. Though controlling narratives usually don't last long if the people who are being withheld information can recognize the signs and are not regular cultists of an ideology.

[@K3wlG33k]

@@syrious_kash8268 er sorry about the sarcastic remarks. I was regretting it after replying

[@kaveh8425]

Thanks for the video, I had the same misunderstanding about how the green house effect works in earth atmosphere! While back I also learned that the common explanation about how regular green houses work is also wrong: most of their warming effect is thru keeping the warm air around the plants (disrupting convection to open air) and not allowing the warmer air to be blown away by cooler wind. This is why green houses made with regular plastic sheets works almost as good as green houses with glass, even though plastic sheets are transparent in infrared wavelength range. In other words, the heat leakage through convection and air escape is much larger than heat leakage through radiation, and conduction (by the green house walls). Comments on some of the replies: [I think my comment was misinterpreted by those who want the believe something and are searching for justifications! All I am saying is the common mechanisms that we often hear about how regular green houses work is not correct. BUT, the green houses work non the less and keep inside warm so does the “green house” gases warm the earth surface though with a different mechanism. More green house gases the warmer things get. Calling the effect green house effect is a misnomer causing confusion but it doesn’t mean the “green house” effect on earth is not real!, what to do about it is a different matter but first let’s get the science right.]

[@OakInch]

Wait until they come out with a better theory. These theories are funded. There will be more.

[@hehehahahmhmhm]

@@OakInch while we are at it we can wait for jesus to come back and say what his take on it.

[@uweburkart373]

All that might be right and ok so far. The problem I have to understand and then to believe that as roughly 70 % is water and seas and not continents, its a much much more complex process. Further, what is the problem anyway? A few changes here another change there, what did the Romans do or what did the Temple Knights do as in their times the average temperatures were higher then today? They lived with it and arranged and survived with it. So will we, unless we kill our economies first by following up all those crap measures the extinction rebels wants us to do! Therefore their naming fits right!

[@stevenheinje181]

@@uweburkart373 I may be a bit skeptical too, with the state of scientific reporting and our political processes, even if I think the science has integrity. For me a little global warming where I live might be ok, but I read a book called Dirt. It’s about soil. I’m not sure he made the point but if you look at farm land and coast lines you see a little sea level rise will have big potential impacts on food security. This is what straightens my hairs. I could immigrate to Canada in an hour, but we don’t need 6 billion people relocating. Beside Floridians moving to the PNW would be awful.

[@rashakor]

Hence why the atmospheric greenhouse effect should not be called greenhouse at all. The cladding of a greenhouse act as a physical barrier to convection. The Earth does not have such barrier hence it is not a greenhouse.

[@sfinxwojerz]

And loosing ice caps will weaken ability of our climate to regulate ,right? so on top of that what you have just said if we look at other aspect of our climate it start to look pretty serious. Correct me if i am wrong.

[@Michel_Muster]

I have to admit, I didn't fully understand. How can we make predictions about such complex systems? And how do you explain Middle Age warm periods? And for me, the most important question, does it matter when it gets warmer?

[@oldvlognewtricks]

We make predictions about complex systems all the time. That is the purpose of the entire subject of differential equations and other mathematical modelling… And arguably science in general. Does it matter if things warm? Only if you don’t mind 40% of the world’s population being under sea levels as the ice caps melt… increasingly severe and unstable weather patterns… desertification and disruption in food production… Trivial stuff like that

[@wopmf4345FxFDxdGaa20]

@@oldvlognewtricks Sure, you can always make predictions. But it is two different things to make predictions and to make useful predictions. Predictions in science usually are bundled with some kind of confidence estimation. Sure, we can make somewhat useful predictions in this topics as well. In reality though, for various different political reasons people like to either exaggerate or underestimate in this topic even though the science at the very bottom would be as good as it can be.

[@wopmf4345FxFDxdGaa20]

@@oldvlognewtricks For example in some fields in science, you can calculate and predict what is going to happen very accurately and very high probability that it is going to happen exactly like that. Some simple event in let's say electricity. But when the thing you are trying to predict gets more and more complex, the reliability of your prediction drops. And when it drops near 50% or less, your prediction is as accurate as flipping a coin . . .

[@oldvlognewtricks]

@@wopmf4345FxFDxdGaa20 The majority of our economy and agriculture relies on accurate modelling of complex systems. Politics can say what it likes, but farmers need to know how to plant and bankers need to know when to sell. Confidence intervals are inevitable in every discipline, but particularly so in situations were 5% is the difference between record growth and a catastrophic recession. Again: the complex predictions you’re talking about are happening all the time, and your existence relies of many of them being accurate within a percent or two.

[@wopmf4345FxFDxdGaa20]

@@oldvlognewtricks Exactly, that is the point. Usually a prediction is always coupled with some estimation about how confident that prediction is. But for some reason, in case of climate, this is often forgotten. The models most successfully used in different fields of economy and agriculture are rather simple. These are fields where the feedback (that is used to correct the model) comes relatively fast. This way the models can be improved very fast which makes them far more useful. In case of climate modeling it is a slightly different case. You don't have active feedback loop like this at the time scales you are trying to predict. All you have is historical data from various different proxies and recorded temperature data from extremely short period of time relative to time scales of climate.

[@bobtarmac1828]

My go-to science teacher. Thank you!!

[@Alekosssvr]

What is swept under the rug is 1. the role of water vapor and 2. the lack of any physical and computational models for the carbon cycle. Unless we can figure out these two items we cannot have a complete radiance model or carbon balance model.

[@BurnettMary]

What are you talking about? Radiative transfer models account for water vapour and all other atmospheric gasses in the same way.

[@brianb4898]

​@@BurnettMaryNot from what I've seen. I specifically looked for a study that covered how low level clouds are a cooler and high level clouds are a warmer, how the cloud coverage varies over time and the relative angle to the sun, how water vapor is a global warmer, how droughts and hurricanes impact the warming, etc ... basically a holistic coverage of water vapor ... and nothing. Models are good, but they are not perfect. I very much remember being lectured to over and over and over again, about how the polar ice caps would be gone in 10 years ... that was around 30 years ago now, so obviously not correct. Also, science requires independent verification, but there is insufficient shared data to replicate the climate models.

[@canis_majoris]

⁠@@brianb4898your anecdote about the polar ice caps is a little peculiar. the IPCC report from 1990 makes no mention that the ice caps “will be gone” in 10 years and in fact states that sea level rise will be mostly from thermal expansion and glaciers melting over the following century. So I dunno who you were debating but it wasn’t climate scientists.

[@gmcenroe]

Clearly the models are inaccurate because they have not been validated by experimental data. Also, CO2 has been much higher than 400ppm with no irreversible damage to the planet. Climate modelers have acknowledged the inaccuracy of their models that ignore water vapor and changes in sun activity. There are also inaccuracies in temperature measurements which have biased the data to higher overall average temperature of the planet. There are too many variables to make accurate predictions but it is always easy to spread fear by misapplying data interpretations.

[@vaxx-1161]

Why do you need a computational model of the carbon cycle when we have an actual physical mapping of it? Look up the Keeling curve which empirically measures CO2 levels since 1958 and you will notice that it's jaw-tooth shaped - this perfectly captures the carbon cycle caused by seasons. But you will also notice that the long-term trajectory of this up and down jaw-tooth pattern is that ppm CO2 is indeed increasing every year. This is pretty well known stuff.

[@mickeyotoole9780]

There have always been El Ninos. It's the increasing CO2 that's the cause of the rapid & ongoing rise in global temperature.

[@AdamRidley11]

The predominant warming effect in a greenhouse is from stopping convection not from reflecting radiation. This is further proved by replacing your glass panels with polycarbonate (almost transparent to infrared). Because polycarbonate has lower thermal conductivity than glass you will actually get a warmer greenhouse despite virtually no infrared reflection at the panels. Another major factor in blocking convection is that you build up the relative humidity which in turn helps absorb the infrared emitted from the surfaces inside.

[@dsp3ncr1]

kzbin.info/www/bejne/pHuvZmqIeaunsM0

[@psychlopes1976]

Love your videos, Ms. Sabine. Keep up the good work. And yes , this was, for me, super useful.

[@AySz88]

Your students are lucky to get something like 3:17 as the "high school" version! I had to wait for a 200-level climate course in college (as an elective) to get the equivalent, a course that was a bit hobbled by lack of physics or calculus prerequisite.

[@samlevi4744]

Yeah, i didn’t even get 6:12 in Gen chem. It took my ADHD wanting to be right in an argument to actually learn that part.

[@lesliemacmillan9932]

A 200-level climate course that had no physics or calculus prerequisite is not a serious climate course.

[@AySz88]

​@@lesliemacmillan9932 I mean, yeah, it was an elective (so more for interest/fun, not those going into the field). Also, was its first run, and by the way they kept having to "dial it back" they too overestimated what high school provides of physics and math, at least for some states.

[@dangurtler7177]

What university doesn't require calculus, physics and differential equations in the first three semesters of work for STEM degree? Something is not right there.

[@AySz88]

@@dangurtler7177 Because the course wasn't part of work for a STEM degree. The course was for students outside the field (including non-STEM colleges of the university, IIRC was pitched at those going for law, business, communications, agriculture, etc).

[@bitsmart...]

Sabine, how the infrared light (heating waves) comes through the earth's atmosphere from the sun but can not go back to space when bounced from the surface of earth and just stays on earth???

[@grindupBaker]

Earth's radiation generally phrased as "long-wave radiation (LWR)" or "long-wave infrared radiation (LWIR)" because " infrared" band is wider than Earth's radiation.

[@Warvideos401]

The radiation which gets through atmosphere is then transfered as heat IR from the surface and convection and so. You are right no heat from sun gets down to earth

[@gabrielapetrie]

This is going to prove so useful for a lot of people for a long(-ish?) time!

[@aronsarmasi2368]

Sabine, great video as always, but I noticed an error in your explanation for why the pressure decreases as you go up. It's actually little to do with the change in the local acceleration due to gravity, and it's simply because the air on top squishes the air on the bottom. Same as in the oceans -- the deeper you go underwater, the higher the pressure.

[@NoelTarlinton]

Hmmm interesting - have often read that gravity is weaker the higher up one goes in the atmosphere (which of course is true) - however did not realise that the air above mainly causes the pressure difference - very good.

[@loodog555]

I actually thought that's what she said: that the pressure change is due to supporting the air on top.

[@albertssj25]

The air squishes due to gravity. Things don't randomly squish each other. Gravitational force pull particles to the center of the object causing the squishing

[@tf2engineer]

"Squeezing" is one way to put it, but it's more accurate to say that air will still diffuse outward. Even if the force on the air were just about uniform, the layer of air around earth would not be uniform, and we would still observe a pressure distribution.

[@douginorlando6260]

What University teaches the change in gravity is what causes the change in air pressure? The same University that cringes at the thought of having to defend their theories by “climate deniers”. That’s why anyone pushing back is labeled a “climate denier” and shunned

[@duelmonitor]

Very interesting video. A couple of additional things I’m curious to understand how they factor into the model. As only 1/2 of the globe receives radiation from the sun at a time, how does night time radiation emission factor into the model? Also you mentioned water being a highly reactive to wiggling, how does the majority of the planet surface being water factor or influence the model? Trying to understand deeper. Thank you.

[@kevpatguiriot]

•

[@Jeremiah6_16]

As a stupid American, thank you for putting. Fahrenheit. It's a small detail but I really appreciate it.

[@wfolta1]

Excellent video and great explanation about how the arrows build the wrong intuition. Could you please add the hydraulic cycle to this? That is, when the lower atmosphere warms, it causes evaporation which causes more water vapor (greenhouse gas) but also absorbs heat. The vapor rises up to almost the stratosphere (at least in the tropics) and condenses which reflects sunlight well above the surface and also releases the latent heat from the water vapor at the doorstep of the stratosphere. Lots of moving parts there: water vapor as a greenhouse gas, clouds reflecting light, and the transport of heat from the surface of the earth up to nearly the stratosphere where it's released. How does this mixture of insulation, umbrella, and heat-pumping work on balance? For bonus points, do you think Elves, Sprites, and Blue Jets transfer significant amounts of energy as well?