โYou Askedโ is a series where Earth Institute experts tackle reader questions on science and sustainability. Over the past few years, weโve received a lot of questions about carbon dioxide โ how it traps heat, how it can have such a big effect if it only makes up a tiny percentage of the atmosphere, and more. With the help of Jason Smerdon, a climate scientist at Columbia Universityโs Lamont-Doherty Earth Observatory, we answer several of those questions here.
How does carbon dioxide trap heat?
Youโve probably already read that carbon dioxide and other greenhouse gases act like a blanket or a cap, trapping some of the heat that Earth might have otherwise radiated out into space. Thatโs the simple answer. But how exactly do certain molecules trap heat? The answer there requires diving into physics and chemistry.
When sunlight reaches Earth, the surface absorbs some of the lightโs energy and reradiates it as infrared waves, which we feel as heat. (Hold your hand over a dark rock on a warm sunny day and you can feel this phenomenon for yourself.) These infrared waves travel up into the atmosphere and will escape back into space if unimpeded.
Oxygen and nitrogen donโt interfere with infrared waves in the atmosphere. Thatโs because molecules are picky about the range of wavelengths that they interact with, Smerdon explained. For example, oxygen and nitrogen absorb energy that has tightly packed wavelengths of around 200 nanometers or less, whereas infrared energy travels at wider and lazier wavelengths of 700 to 1,000,000 nanometers. Those ranges donโt overlap, so to oxygen and nitrogen, itโs as if the infrared waves donโt even exist; they let the waves (and heat) pass freely through the atmosphere.
With CO2 and other greenhouse gases, itโs different. Carbon dioxide, for example, absorbs energy at a variety of wavelengths between 2,000 and 15,000 nanometers โ a range that overlaps with that of infrared energy. As CO2 soaks up this infrared energy, it vibrates and re-emits the infrared energy back in all directions. About half of that energy goes out into space, and about half of it returns to Earth as heat, contributing to the โgreenhouse effect.โ
Smerdon says that the reason why some molecules absorb infrared waves and some donโt โdepends on their geometry and their composition.โ He explained that oxygen and nitrogen molecules are simple โ theyโre each made up of only two atoms of the same element โ which narrows their movements and the variety of wavelengths they can interact with. But greenhouse gases like CO2 and methane are made up of three or more atoms, which gives them a larger variety of ways to stretch and bend and twist. That means they can absorb a wider range of wavelengths โ including infrared waves.
How can I see for myself that CO2 absorbs heat?
As an experiment that can be done in the home or the classroom, Smerdon recommends filling one soda bottle with CO2 (perhaps from a soda machine) and filling a second bottle with ambient air. โIf you expose them both to a heat lamp, the CO2 bottle will warm up much more than the bottle with just ambient air,โ he says. He recommends checking the bottle temperatures with a no-touch infrared thermometer. Youโll also want to make sure that you use the same style of bottle for each, and that both bottles receive the same amount of light from the lamp. Hereโs a video of a similar experiment:
A more logistically challenging experiment that Smerdon recommends involves putting an infrared camera and a candle at opposite ends of a closed tube. When the tube is filled with ambient air, the camera picks up the infrared heat from the candle clearly. But once the tube is filled with carbon dioxide, the infrared image of the flame disappears, because the CO2 in the tube absorbs and scatters the heat from the candle in all directions, and therefore blurs out the image of the candle. There are several videos of the experiment online, including this one:
Why does carbon dioxide let heat in, but not out?
Energy enters our atmosphere as visible light, whereas it tries to leave as infrared energy. In other words, โenergy coming into our planet from the Sun arrives as one currency, and it leaves in another,โ said Smerdon.
CO2 molecules donโt really interact with sunlightโs wavelengths. Only after the Earth absorbs sunlight and reemits the energy as infrared waves can the CO2 and other greenhouse gases absorb the energy.
How can CO2 trap so much heat if it only makes up 0.04% of the atmosphere? Arenโt the molecules spaced too far apart?
Before humans began burning fossil fuels, naturally occurring greenhouse gases helped to make Earthโs climate habitable. Without them, the planetโs average temperature would be below freezing. So we know that even very low, natural levels of carbon dioxide and other greenhouse gases can make a huge difference in Earthโs climate.
Today, CO2 levels are higher than they have been in at least 3 million years. And although they still account for only 0.04% of the atmosphere, that still adds up to billions upon billions of tons of heat-trapping gas. For example, in 2019 alone, humans dumped 36.44 billion tonnes of CO2 into the atmosphere, where it will linger for hundreds of years. So there are plenty of CO2 molecules to provide a heat-trapping blanket across the entire atmosphere.
In addition, โtrace amounts of a substance can have a large impact on a system,โ explains Smerdon. Borrowing an analogy from Penn State meteorology professor David Titley, Smerdon said that โIf someone my size drinks two beers, my blood alcohol content will be about 0.04 percent. That is right when the human body starts to feel the effects of alcohol.โ Commercial drivers with a blood alcohol content of 0.04% can be convicted for driving under the influence.
โSimilarly, it doesnโt take that much cyanide to poison a person,โ adds Smerdon. โIt has to do with how that specific substance interacts with the larger system and what it does to influence that system.โ
In the case of greenhouse gases, the planetโs temperature is a balance between how much energy comes in versus how much energy goes out. Ultimately, any increase in the amount of heat-trapping means that the Earthโs surface gets hotter. (For a more advanced discussion of the thermodynamics involved, check out this NASA page.)
If thereโs more water than CO2 in the atmosphere, how do we know that water isnโt to blame for climate change?
Water is indeed a greenhouse gas. It absorbs and re-emits infrared radiation, and thus makes the planet warmer. However, Smerdon says the amount of water vapor in the atmosphere is a consequence of warming rather than a driving force, because warmer air holds more water.
โWe know this on a seasonal level,โ he explains. โItโs generally drier in the winter when our local atmosphere is colder, and itโs more humid in the summer when itโs warmer.โ
As carbon dioxide and other greenhouse gases heat up the planet, more water evaporates into the atmosphere, which in turn raises the temperature further. However, a hypothetical villain would not be able to exacerbate climate change by trying to pump more water vapor into the atmosphere, says Smerdon. โIt would all rain out because temperature determines how much moisture can actually be held by the atmosphere.โ
Similarly, it makes no sense to try to remove water vapor from the atmosphere, because natural, temperature-driven evaporation from plants and bodies of water would immediately replace it. To reduce water vapor in the atmosphere, we must lower global temperatures by reducing other greenhouse gases.
If Venus has an atmosphere thatโs 95% CO2, shouldnโt it be a lot hotter than Earth?
The concentration of CO2 in Venusโ atmosphere is about 2,400 times higher than that of Earth. Yet the average temperature of Venus is only about 15 times higher. What gives?
Interestingly enough, part of the answer has to do with water vapor. According to Smerdon, scientists think that long ago, Venus experienced a runaway greenhouse effect that boiled away almost all of the planetโs water โ and water vapor, remember, is also a heat-trapping gas.
โIt doesnโt have water vapor in its atmosphere, which is an important factor,โ says Smerdon. โAnd then the other important factor is Venus has all these crazy sulfuric acid clouds.โ
High up in Venusโ atmosphere, he explained, clouds of sulfuric acid block about 75% of incoming sunlight. That means the vast majority of sunlight never gets a chance to reach the planetโs surface, return to the atmosphere as infrared energy, and get trapped by all that CO2 in the atmosphere.
Wonโt the plants, ocean, and soil just absorb all the excess CO2?
Eventually โฆ in several thousand years or so.
Plants, the oceans, and soil are natural carbon sinks โ they remove some carbon dioxide from the atmosphere and store it underground, underwater, or in roots and tree trunks. Without human activity, the vast amounts of carbon in coal, oil, and natural gas deposits would have remained stored underground and mostly separate from the rest of the carbon cycle. But by burning these fossil fuels, humans are adding a lot more carbon into the atmosphere and ocean, and the carbon sinks donโt work fast enough to clean up our mess.
Itโs like watering your garden with a firehose. Even though plants absorb water, they can only do so at a set rate, and if you keep running the firehose, your yard is going to flood. Currently our atmosphere and ocean are flooded with CO2, and we can see that the carbon sinks canโt keep up because the concentrations of CO2 in the atmosphere and oceans are rising quickly.
Unfortunately, we donโt have thousands of years to wait for nature to absorb the flood of CO2. By then, billions of people would have suffered and died from the impacts of climate change; there would be mass extinctions, and our beautiful planet would become unrecognizable. We can avoid much of that damage and suffering through a combination of decarbonizing our energy supply, pulling CO2 out the atmosphere, and developing more sustainable ways of thriving.
Editorโs note (March 17, 2021): This post was updated with additional links to Youtube videos with experiments showing the effects of carbon dioxide. Enjoy!
The atmosphere of Mars is nearly the same as that of Venus in CO2 content. Why then is it so cold there? It too, is thought to have had oceans at one time, and experiences polar ice so water vapor is present.
The question is can we see a study that shows co2 is not responsible for climate change ?
I have looked but I canโt find any, and I really want to see one from credible source.
That’s because it’s not true. The skeptics and deniers have never produced a model showing that CO2 isn’t to blame for global warming, because they can’t–unless they intentionally change the laws of physics and thermodynamics in the model to be different from this universe.
How can a molecule that has an equivalent density distrubution of 4 people in a field of 10,000 make a significant impact on retaining heat. I would like a precise mathematical response please not supposition.
The density distribution has little to do with how much heat co2 absorbs. Why would that matter? Density alone cant determine how much heat something absorbs.we can measure how much co2 is in the atmosphere, along with methane and other emissions. When there are more things in our atmosphere that can absorb heat it gets hotter.
I’m certainly no expert, just the average layman, confused about all the theories and arguments on the subject of climate change due to carbon emissions.
I’m also old enough to remember all the hysteria about chlorofluorocarbons back in the 80s and 90s creating a hole in the ozone layer that was, supposedly, never going to be able to repair itself… but it has! Naysayers must have been really disappointed, but they’ve now cottoned on to a new hysteria that causes global warming, carbon emissions!
I’m not suggesting that global warming due to carbon emissions is not true (I really just don’t know), my argument is that, in Australia at least where we only contribute around 1.3% of total global carbon emissions, what can we (Australia) do about it? If plants reduce the carbon emissions, why are we destroying farmland, forests,etc to build solar and wind farms? Why are we, as Australians, having to suffer increased costs of living (due to this energy renewal abomination) for no result in decreasing global warming?
Why won’t the Labor government even have a discussion, debate or, better still, have a referendum on introducing nuclear powered energy to our energy mix?
Final word. China, and South America are by far the biggest contributor to carbon emissions. Unless they are on board to do something about it, we are just wasting our time going through all the pain of transitioning to renewable energy. May as well rebuild our coal powered power stations or go nuclear.
Chlorofourocarbons was not a hysteria. It was and still is a real threat. Fortunately, by humans banding together and agreeing to no longer produce chloroflourocarbons and releasing them into the atmosphere was the problem rectified. The same solution to the greenhouse gas problem is for humans t band together and agree not to release so much CO2 and methane into the atmosphere.
This entire article is misleading. The carbon content in our atmosphere could double to 0.08 and there would be little to no measurable change. You would see all plant life flourishing. CO2 actually follows warming in the historical record. And that change is easy to figure out. Warmer water holds less co2. Real climate/greenhouse gas is sulfuric dioxide. 100โs of times more related to global warming. Look at volcanic activity and you will see temps rise after long periods of major volcanic activity.
Two questions: Why doesnโt CO2 in the atmosphere interact with incoming solar radiation to reduce photons hitting the earth? Secondly, does increased activation energy of atmospheric CO2 fall each night once the sun goes down?
did you know the 2015 Paris Climate Accord is silent on the Second Law of Thermodynamics (entropy)? Think about that for a moment. The UN’s scientific models for mitigating global warming does not consider the Second Law of Thermodynamics (entropy). It is my opinion, ignoring entropy in global warming science is the equivalent of ignoring Newton’s Second Law (F=MA) in rocket science. However, I have perused dozens of environmental NGO’s and university websites and the Columbia Climate School is the only institution I have found that mentions entropy as a factor in modeling global warming remediation:
Radiation physics is not a theory of climate.Collisional relaxation of 15ฮผ vibrationally excited COโ increases the K.E. of the troposphere.
The central question is how the climate responds. The atmosphere warms if nothing else changes.
If cloud albedo increases so that TOA irradiance declines by ~0.3%, or the frequency and intensity of tropical thunderstorms increase, any change in sensible heat could be undetectable.
wouldn’t it be better to plant more green plant to convert CO2 to O? As apposed of clear cutting forest and replacing them with Chinese built solar panels.
Absolute scientific non science alarmism. The heat originated in the sun the remissions from Carbon Dioxide are the same solar energy not something additional heating the planet. We know the effect saturate and did so at lower co2 levels than today. There are too many fallacious claims that many scientists have refuted and the 97% consensus is an absolute untruth.
why is co2 considered to play such a massive role in the greenhouse effects
Since we are on a globe by definition there is a lot more up than down. So how can you say half goes up and half goes down?
Sorry this is not a technical response to the original question.
I would like to note that all this CO2 we are emitting was taken from the atmosphere, albeit 200 to 360 million years ago. That means the CO2 levels had to have been much higher then. Of course we would not have been very comfortable in the environment in the age of the amphibians. In burning hydrocarbons we are also releasing water, though it is a small fraction of what is already in the atmosphere.
Climate change has ended empires in the past and led to mass migrations, but never threatened human extinction. We survive multiple ice age glacial periods with animal skins and stone axes, so the “existential threat” to modern man is not creditable. I don’t know if all the alarmist even believe it, but it is a political expediency because you often cannot get the masses to move from the comfortable norm unless they perceive an emergency or imminent threat.
Does man impact the environment? I believe so. We see it in local impacts to wetlands, deforestation, etc. and I think we do globally, also. I read humans may be the third largest biomass on earth (depends on how specific you are with species). On early Earth, the anaerobic bacteria never wiped themselves out by polluting the atmosphere with oxygen. Personally I appreciate their sacrifice. We we face mass extinctions? From Wikipedia a take this quote of what happened over 200 million years ago:
“There was a major restructuring of wetland forests during the Kasimovian glacial interval, with the loss of arborescent (tree-like) lycopisids and other wetland groups, and a general decline in biodiversity. These events are attributed to the drop in CO2 levels below 400 ppm.[22][36][37]”
Some of the interventions seem preposterous to me. Bill Gates wants to cut down 7 million acres of trees and not use the wood but bury it. Good, coal for future generations. Someone proposed a giant space mirror, which has too many negatives to list here, but you could build one 100 times the size on the surface for the cost. Some suggest clouding the stratosphere with sulfur dioxide particles to reflect the sun light. Wasn’t that what we got from burning coal that caused acid rain?
As for petroleum, we will need to keep some of it until we can synthesize all the equivalents from bio sources. Are you going to lube the wheel bearings on your electric car with tallow? No, because we going to do away with the cows and pigs. As an EE, I am pro-electric but I would note that gasoline cars at first were expensive toys for the rich. They were not practical, but engineering made them far less expensive and more reliable. Their adoption did not require taxing hay or shooting all the horses.
So we have people with their ears to the track and some say a train is coming around the bend and others say they hear no train. My advice is if you don’t know, get off the track. But don’t start running the opposite direction.
My mindset is along that of Elon Musk’s. Let’s do what we can to keep Earth habitable (Tesla, Solar City) but keep the growth of humanity to beyond this rock (Space X). That which stops growing is dying.
Look at the devastation caused by massive environmental engineering in the past in Russia and China before we hand over too much power to a global technocracy. Instead of flying your private jets to Switzerland, pant a tree in your back yard.
Plant more trees to absorb CO2!!!
Hi .. I have a (probably daft) question; it says in this article that light comes from the sun and hits earth’s atmosphere as mainly visible light and leaves as infra red. So I got interested and ended up on on space.com where it says; “most of the time, what we see radiating out from our host star are infrared wavelengths, ultraviolet wavelengths and, of course, visible wavelengths that we can see with the unaided eye.
I was immediately confused – then assumed that it’s the amounts that must be the key point. What are the amounts of infra-red versus visible light in relation to each other and their warming effect on earth (ignoring the knock-on CO2 effect for now). Thanks – interested in learning.
My question is how can CO2 do anything to the atmosphere if its emissivity is only .002 relative to a black body and if its emissivity is virtually 0 below 33C as discovered experimentally by Hoyt Hottel 1954, Bo Leckner 1972 and Nasif Nahle 2011. It can hardly absorb or emit any IR radiation at atmospheric temperatures and it certainly does not trap heat.
It would help if you read some of Prof Plimer’s work(Australia).Further,Co2 levels are not in fact always related to global temperature change. Much of the “data” has been altered or ignored to feed the belief that there is a mathematical relationship between high Co2 levels and high temperatures. The data we are allowed to see only applies to the last 100 years a mere dot in the evolution of Earth’s climate.
I would love to replicate this demonstration of the heating effects of Carbon Dioxide in the atmosphere for a public display in Chicago. However, rather than filling a bottle with pure carbon dioxide, do you think that there would be a measurable heating effect if the one bottle had air in it with say 500ppm of carbon dioxide, or at most 600ppm? Pure CO2 would provide fodder to the climate deniers. The challenge is to use a very well-insulated container to retain the generated heat as much as possible to maximize the temperature rise.
Let me know what you think,
Thank you,
John T Katrakis, PE, LEED AP
J. T. Katrakis & Associates, Inc.
Barrington, IL
John, you raise a good point, Temperature changes could be better examined with a more sophisticated experiment combining Nitrogen, Oxygen, inert gases, carbon and methane levels injected into inert glass spheres at the same mix of earths atmosphere, utilizing heat sources that mimic the sun, and take into account Milankovitch cycles, etc.
Are there any white papers you can recommend that would speak to this? #notascientist
The mai ertorcin this artikler is that it is claimed that IR absorbed energi is immendetly reemiited at the same wavelengt. This is against the last of physic. When CO2 or H2O absorb IR-radiation this case the molecyle to vibrator and spin. Main part of absorbed energy is transfered to other molecyles by collisions. Ne IR radiator is based on the temperature ( vibrations) of the molecyle an lover in freqeuens than original IR transittmottak from the ground.
ALso importert is wave -partikler dualtion of photons. One photon can only be stopped once innthe Atmosphere. That tell youthat it is a limit to temperature increase doe to absorbtion.
Seems to me you are missing an important point….
The fact is there is no lab experiment to prove a .0125% increase in CO2 has any real effect on temperature. None!
Now if you want to fill a bottle full of CO2 yes you will get a temp increase because it is a greenhouse gas but we are talking 20%, 30% 60% increases in CO2, not a .0125%.
You are talking about CO2 magically increasing it forcing 1000s of times. How is this even possible?
Your claim is CO2 increases water vapor, but if a .0125% increase has no real effect on temp how is that feedback or any feedback for that matter possible?
Like putting a drop of red dye in a pool then expecting it to turn red….
Given that 14oC is the average temperature …what is the temperature component produced in oC by carbon dioxide in that 14oc.
If water vapor holds more heat, then why do the hottest places on earth have very low humidity?
The magnetic field of the earth reflects almost all I.R. radiation that should provoke the greenhouse effect.
I saw that you have the word, ‘heat’ where I might put the word ‘energy’. I had someone with a contrary view point out that the photon re-emitted from COโ is not ‘heat’, (which is an emergent phenomenon of a collection of interacting atoms / molecules.
I think that, technically, the objection is correct. I don’t have a problem with use of the word ‘heat’ in this way, but if I share this article, I may hear that objection again.
So many issues folks have with the statements in this post, but one really bothered me.
It is asserted that in winter, it’s drier, and in summer it’s wetter.
Ummm… does someone not understand the terms “summer” and “winter”????
For those new to Planet Earth: “summer” is characterized by warmer temperatures and lower rainfall, while “winter” is characterized by lower tempuratures and higher rainfall.
You want credibility in the eyes of “deniers” then don’t make statements that indicate you are ignorant of the basics of seasonal change.
If it seems you don’t even have a basic understanding of earth’s weather, then any statements of a more sohisticated nature cannot be considered to have use, value, or validity.
How can I calculate the effect of carbon dioxide on climate change using first principles as opposed to empirical models?
I would like to say one more thing about this climate change thing.
When I was a kid, our Sun was yellow. The ice caps on Mars are melting. The Eye of Jupiter is disappearing. We seem to have a lot of space debris falling on us lately. Meteors.
I think this warming is solar system-wide.
Something is coming our way. Something big. Something that has perturbed our Sun. Keep your eyes on the skies.
You added a liquid to the CO2 bottle and did not to the other. How is that comparative science. You should put room air in one and room air plus the .04% carbon dioxide as it is in real life. The temp difference would be negligible. The experiment is nonsense. Besides, O2 is lighter than Co2 and is therefore a ground gas. When making Co2 you can see it head for the ground. If it did not, we would all suffocate. More Co2 means more vegetation. To cover the Earth, thereby cooling it. More rain. More cooling. Quit playing God. The Earth can handle it by itself.
Accurate!
The existence of heat Islands around suburban areas is proof by contradiction that waste heat has greater effect than IR radiation.
At the same time; global warming can cause or exacerbate sleep issues like sleep apnea, and ways to help cure or manage it:
– Higher temperatures and more extreme heat events disrupt normal sleep cycles. This stresses the body and makes it harder to fall/stay asleep.
– Warming trends lead to longer and more intense pollen seasons. Higher pollen counts trigger more allergies and irritate airways, worsening sleep apnea.
– Hot nights reduce sleep quality as the body has a harder time cooling down to normal sleeping temperatures. Poor sleep amplifies daytime sleepiness.
– Rising CO2 levels increase plant/pollen production that triggers asthma and allergies linked to inflammatory sleep issues.
– Heat waves and humidity spur greater ozone pollution which irritates lungs and contributes to sleep apnea development/severity.
To help cure or manage sleep apnea exacerbated by global warming and climate change:
– Use air conditioning and fans to keep bedrooms cool for better sleep during warm nights.
– Manage allergies/asthma with medications to reduce inflammation and keep airways open.
– Try a CPAP machine or other prescribed sleep apnea treatments to help prevent breathing issues.
– Improve indoor air quality with filters and maintain a consistent sleep schedule.
– Address weight issues which worsen apnea as obesity rates rise with increasingly sedentary lifestyles.
– Reduce overall environmental impacts by supporting efforts to transition to renewable energy and curb further climate change.
Great easy to understand summary. There have been some recent discussions in the press around clouds being a far more powerful greenhouse gas influencer than CO2. Trying to make sense of this. This โcloudโ line of logic seems to be based on the notion that cloud cover (water vapour) reflects sunlight before it even contacts the earth and converts to infrared radiation. Any help with my education would be appreciated!
It is hard for me to accept that this is an accurate representation of the heating and cooling of CO2 in the atmosphere. Energy is transferred in discrete quanta and, I think, energy-in causes the balance between the kinetic energy within the molecule and the attractive force that balances to be disturbed so that the kinetic energy increases offset by the energy of the quanta. Energy-out causes the molecule to return to its original condition.
Also heat transfer occurs when there is a temperature difference between one media and the adjacent one.
So, the earth heats up during the day and it radiates energy out when the temperature of the sky is lower than the temperature of the earth. OK ?
At night the Earth is cooling but what about the CO2 hi in the atmosphere? Is it cooling? What causes the energy in the CO2 to head towards the Earth if that Earth has a higher temperature that the CO2. And if the “space” appears to be at a lower temperature than the CO2 surely all the CO2 released energy will head out.
I raise these questions because the heating rate of the Earth does not seem directly proportional to the amount of CO2 up there. Look at the graphs from Berkeley Earth.
I realize that the “models” I have discussed are not a good statistical representation of what is going on but can any body please enlighten me?
Wonderful! Very clear and understandable explanation. I have a background in the sciences, and I was looking for a simple way to explain the greenhouse effect to my friends. I love the idea of showing people how to experience the reality of CO2 role in trapping heat.
Sorry I didn’t read all of the comments so you have probably answered this: Have you experimented to see how this affects the plants on the earth? I’m worried my garden won’t grow. Thanks.
Very useful.
The article gives a long and detailed discussion as to how CO2 might lead to the earth warming. However it does not answer my question which was to demonstrate a PROVEN link between atmospheric CO2 levels and changes in the earth’s CLIMATE or weather patterns. Infact I’ve yet to see an argument that demonstrates this link.
It is disturbing that no one has seen fit to “prove” that Doubling the earths CO2 to 800ppm would have a significant effect on the earth’s heat balance.
The actual literature shows the opposite, that the hypothesis is false.
NASA data shows zero energy going to space in the 14-16micron range, the only range where CO2 is effective.
Thus more CO2 will ahve no effect. So the zealots will have to find another story to peddle.
This data has been in use for decades by the IR Astronomy folks, with no complaints, so it can be termed reliable.
According to the best papers I’ve seen, the emissivity of CO2 is 0.0017. This is the paper by Leckner from the 70’s. That means there’s a shockingly low amount on infrared radiation emitted by the Earth’s surface, that actually is absorbed and re-emitted back to the Earth’s surface. Radiation is also a very weak mode of heat transfer, and the Earth is not a perfect blackbody. By my calculations, roughly 0.00000035รEarth emitted IR radiation, is actually re-emitted back towards the Earth’s surface. I’ve read papers by climate scientists, where they assume CO2 has an emissivity of 1.0. This is pretty intellectually dishonest. I suspect it’s why none of the dire predictions have been even close to correct. For reference, I have a master’s in ME from Stanford, and worked most of my career as a spacecraft thermal design engineer for the US Naval Research Laboratory. I did radiation heat transfer calculations almost daily for over a decade. If my models weren’t correct, and properly correlated to testing, spacecrafts would fail to work, and I’d likely have been fired. Climate scientists never get fired, despite their predictions being wrong 100% of the time.
“Without human activity, the vast amounts of carbon in coal, oil, and natural gas deposits would have remained stored underground and mostly separate from the rest of the carbon cycle.”
Long long ago that carbon (stored underground) also belonged to the carbon cycle of that time. Who decides how much carbon should be in the current cycle?
With growing energy demands around the world, and a trend towards solar etc, at what point will our ability to collect such energies start to act in the same way as Co2, and so become a major contributor towards global warming? Would we at some point need to begin exporting energy away from the planet? If this is not a real factor could we not use air source heat pumps to extract heat from the air/atmosphere like ground source heat pumps do from the ground and utilize that energy?
The article says that after a CO2 molecule radiates out its captured energy it goes into space or back to earth. That’s not quite complete. It heads in those directions, but can also be captured by another CO2 molecule. As the concentration of CO2 increases, the likelihood increases that the heat will stay in the atmosphere for quite a while.
For the experiment why not just have a jar with .04% CO2. Seems misleading to fill a jar with 100% CO2 when there is only 0.04% in the atmosphere.
You’re correct. It’s purposefully misleading. There’s no standardized test for measuring the emissivity of gases. The best test and paper written on the subject of CO2, was by Leckner in the 1970s. He concluded CO2 had an emissivity of 0.0017. Climate scientists assume CO2 has an emissivity of 1.0. That’s quite a big difference!
Then what explains the lag seen in fossil records? Heat transfer should literally travel at the speed of light.
Given that water vapour is apparently the No1 contributor to global warming and H2 is mostly ( 90%) produced from natural gas (thus creating CO2 and CO) as by products and then on burning produces water vapour as exhaust then how can this possibly be seen as better than burning oil products????
cant agree with this
I am amazed about the good arguments here. As a German coming from a farming family I am more interested in performing work which influences the surplus of CO2. We see that Israel transformed all its deserts into green land and SEKEM in Egypt is doing the same for about 40 years. There are still quite a few deserts which can easily be transformed into forests and green land. Are there not many healthy young persons doing actually nothing who could perform this work, I mean the few million soldiers? They can do it during their holidays. My question is what amount of the present surplus of CO2 will be used then if this work is done? Or would it be necessary to make more CO2 as done in the past, just to cover the new need of CO2 ? This is a difficult mathematicle question, and in mathe I am not so good anymore having reached 83.
0.04 % CO2 in the atmosphere is enough to “blanket” an earth size planet to the extent to increase global temperature?
Theoretically what depth such a “blanket” should have?
You are writing: visible light enters the earth. Havent you thought about UV radiation? UV radiation especially UV B has increased the last 30 – 40 years by 6 percent in the troposphere. And ironically it is absorbed there by surfaces or exactly Nitrogen and Oxygen which make up 99 percent of the atmosphere hahaha.
I believe we must close the Ozon layer to reduce climate change. CO2 and Methane emissions are definitely not the whole story. Plus the sun is on its maximum for the last 8000 years.
Whats your thoughts on that?
You can look this stuff up (Max Planck Institute and Nasa)
I’ll send you the links if you want.
In the experiment shown the Co2 concentration in the bottle would be massively higher than the actual 400 parts per million. A truer experiment would be to correctly measure the increase of Co2 by say 100% then measure any heat increase I am of the opinion that it would be so small it would not even register on the thermometer 0.04% of the atmosphere is Co2 cutting trees caused more damage than all of the automotive industry . Experiments need to be done accurately or they are pointless
The “explanation” offered in this article falls short of rebutting the valid and most basic criticism of CO2 driven climate change.
First, the experiments given are used to show that CO2 absorbs infrared radiation. I have no argument with that. It does. However these experiments are using near 100% CO2. That is not representative of our atmosphere at all where CO2 is presently at 400ppm, or about four parts in 10 thousand.
The analogy of a person drinking just a small amount of alcohol and getting drunk is false equivalency. The human body is incredibly complex with specific cellular receptors in different parts of the body. A small amount of substance can impeded or promote the transcription of proteins and change physiology substantially. Our atmosphere, though complicated behaves in aggregate. It’s like looking a highly tuned race car engine as just a pile of metal and plastic that weighs a ton. Put a liter of water in the radiator, everything runs great. Put that same water in the fuel tank and it doesn’t function at all.
The comparison of the earth’s temperature to Venus is another example of how this article misleads the reader. The temperature of Venus is 15 times hotter than the Earth? Really? It’s astonishing that this kind of basic error in analysis would be offered here. What temperature scale are you using? Fahrenheit? Yes, you are. This is not a valid way to compare temperatures. It’s equivalent to saying if it is 1 degree F today and it will be 10 degree F tomorrow it’s ten times colder today. If you use the absolute scale of temp, Kelvin, you will arrive at a much different answer. That’s neither here nor there with regard to the thesis of this piece. I simply point out that this article is using all sorts of distortions to avoid the biggest problem:
CO2 has been cyclical for 700 thousand years per antarctic ice core data. Why did it go up and down if there were no anthropogenic sources of CO2? The answer is very clear, atmospheric CO2 levels are primarily a function of the planetary temperature. When temperature goes up, CO2 becomes less soluble in water and atmospheric CO2 rises. The opposite happens when the planet gets cooler. Temperature is driving CO2 levels, not the other way around.
So what is driving Temperature? Insolation, the relative amount of solar energy being absorbed by the surface. This level varies with orbital control, ie the result of eccentricity, obliquity and precession of the earths axis. This has reliably explained the initiation and ending of the last seven or more ice ages.
All this being said, it is important for us to find cleaner sources of energy, stop dumping plastics in our water, preserve natural habitats, use more efficient appliances, etc. etc. But please stop pushing this carbon footprint minimization as the thrust of a solution. It’s non-sensical. The more pseudo science that is being offered by revered institutions like Columbia University the more the public will distrust “the experts”. Once you have lost the trust of discerning people we will have a much bigger problem on our hands.
You make good points. To add to your point, the best measured emissivity of CO2 is 0.0017 by Leckner in the 1970s. There is no standardized test for obtaining the emissivity of gases. Therefore, the vast majority of infrared radiation emitted from the Earth’s surface, passes directly through CO2 molecules. I’ve read several papers by so-called climates scientists, where they assume CO2 absorbs and re-emits all IR radiation. People wonder why these climate scientists have never gotten a single prediction even close to correct. It’s not difficult to figure that out. I’m a space raft thermal engineer with a master’s in ME from Stanford. Consequently, I’m able to easily pick out the false assumptions.
Is there a similar video (or better yet a peer reviewed paper) to the “Greenhouse effect in a bottle explained” under more controlled conditions (or in-field conditions) and with better instrumentation? Thanks.
Great presentation. One question CO2: is especially effective in absorbing IR of 700/cm but the text speaks of longer wave lengths starting at 2000/cm. Did I read that wrong?
Where does H2O fit in to these equations?