The Greenhouse Gas Demo
The Greenhouse Gas Demo

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This discusses a short, but very effective and dramatic demo to show the effect on temperature of increased levels of carbon dioxide.


Mophead Mom : I can point out several things about this that are suspect....

jeffrey tolliver : How much CO2 is that bottle? What about the added pressure? I’m more curious to see how much effect there is by adding like 100 PPM of CO2

D. L. : You did not correct for pressure differences now definetly present in the two bottles. You created vapor in the alkaseltzer-bottle so now the air is more saturated.

steve tarrant : Wow. I get it. Never Again will I take alka seltzer and walk out into the sun. It's a death trap. Thanks dude.

Anthony Pepe : what about the kinetic energy variable? The effervescent is causing an excited state in one bottle but not the other. shouldn't you create a kinetic energy in the other to cancel out the possibility that the average kinetic energy is not increasing the temperature of the atmosphere in that area?

Main 1 : anyone know of a similar lab experiment to this with better controls? This one has too many problems

Lundqvj RL : In all fairness would not the bubbles in the co2 bottle be enough to trap more of the light/heat giving you the difference? Like mini greenhouse within a greenhouse?

ufewl : lol the lamp is only pointing at the CO2 bottle!!! Look it light up like a Christmas tree!!

josephus333333 : This "experiment" is totally inadequate and flawed. The tablets change the molecular structure in the water and actually help increase the absorption of the thermal rays. If you really want to do a proper experiment, replace the air with C02 gas out of a compressed gas bottle. And what you will find that there will be no difference.

xekutive : bad video sir

Chris Warren : What was the software and brand/model of temperature probes?

Dark Mode : Love the flexing with the Vernier temp things

IskurBlast : And that has been published in the peer reviewed literature so shut it!! Wagner et al. Climate change in a shoebox: Right result, wrong physics American Journal of Physics, Volume 78, Issue 5, pp. 536-540 (2010).

IskurBlast : You would get the same result if you used Argon which has no IR properties.

IskurBlast : Why would a paper need to be written that CO2 in a bottle is an example of specific heat capacity and not IR trapping. That is the established science.

64jcl : Fantastic. Now go write a scientific paper on this and get it peer reviewed. I am sure the scientific community would love to hear an alternative that can refute the established science...

IskurBlast : Because you aren't showing the greenhouse gas effect. The CO2 has a different specific heat capacity than air . That is all your are showing. The IR effects of CO2 over such a short distance is so small you cant measure it with a typical thermometer the only way it can be measured is with expensive spectroscopic equipment.

john kosowski : 64, is there a difference between a container and an atmosphere? If so, what is the difference?

john kosowski : Is our atmosphere encapsulated in a plastic bottle? What was the change in CO2? Was there a pressure change in the CO2 bottle? Too many other variables to make this a good experiment, as noted by all of the comments. It doesn't mean that there is no GHE, but it sure doesn't mean that there is one either. I would be more interested in a scientific explanation of how CO2 in the atmosphere which is at a lower temperature cause the earth, which is at a higher temperature, to heat up. Thanks.

grindupBaker : Some genius brainiac CO2pirate here says it's not the CO2 & heat lamp, but CO2pirate is too proud in his brainy magnificence to tell the rest of the world what it really is. Hey brainy CO2pirate I figured it out right away. Erik is far closer to bottle 2 and he clearly has "morning breath". where's my prize ?

grindupBaker : Erik could ask the commenters to do the science & math of chemical heat and how much that would heat the water but since they are too lazy and don't have the mental equipment he could suggest they simply repeat the Alka-Seltzer experiment with no heat lamp but everything else the same and compare the temperature rise caused in 55 minutes with the heat lamp one. Duh. Does our species deserve to survive ?

Gustavo Naspolini : The result is not conclusive to me. 1) I'm sure you should turn the lamp on only after several hours (maybe a day) so that the effect of the effeverscence on temperature is cancelled. 2) MAYBE you should equalize the pressure of both bottles by means of releasing the pressure of the carbonated one until it reaches the atmospheric pressure (as that's the pressure of the non-carbonated one). I say "MAYBE" because I dont have full understanding of the effect of CO2 on the atmosphere.

Victor Hugo Soares : Hey! I have a doubt. Sorry for a stupid question.. but have so many time that i studied it at high school.. that i dont remember anymore.. =p So, the question is: Is the reaction NaCO3 + H2O an exothermic reaction?

billybush111 : I would assume then, that if you pulled the stopper and released the pressure, the temperature would immediately drop to that of the CO2-free container. Why don't you try that experiment and share the results with us?

64jcl : Are you trying to explain away the fact that CO2 traps heat? Please be clear when you post this that you think that all the other things you conjure up here have scientific significance over the proven fact that CO2 traps heat. For what I know some of them might have an effect, but how much? It still doesnt change the fact that CO2 is a greenhouse gas.

Jonathan Gal : Also, the reaction of the Alka Selzer with water is - I think - a heat generating reaction ... a source of heat in the CO2 bottle, which is not present in the control bottle and could also explain the temperature differential.

Jonathan Gal : I agree with Paul Kuhns. The temp difference could be explained by pressure buildup in the CO2 bottle. The experiment needs some more sophisticated equipment, in order to ensure that the temp difference is not driven by a pressure difference. The bottles should each have a pressure release valve that allows gas to escape to equalize the pressure. Also CO2 sensors, humidity sensors, and pressure sensors. Monitor all three, and also temperature, of course.

Norman Baratheon : the experiment is probably correct and you are mad about it, so you want desperately to believe it is wrong, and you want us to explain you why it might be wrong. But you are not brave enough to admit it, so you try to impress us and make us believe that you already know why it is wrong. But you failed miserably because I'm smarter than you and I caught you. Otherwise you could just have explained to us why it is "total bunkum" like you say.

c02Pirate : This is without doubt the most stupid example of C02 warming I've ever seen. There are more mistakes, misinterpretations and straight out scientific ignorance than I care to mention. This silly exercise doesn't even come close to emulating what the GHG hypothesis states - it is total bunkum. Anyone care to illuminate the ignorant on how this silly exercise really works? Hint - it has NOTHING to do with C02. Anyone?

Wilbert Robichaud : with wet droughts and dry floods.

Cyrus Slapatich : LOL. I'm sure you could probably pass that off to the Climate crowd as science.

Wilbert Robichaud : LOL ..and by removing some they will be able to make Africa cooler ... a real man made global temperature control. We could even apply for the kind of temperature we want for holidays . That would create a lot of job since we will be able to Pre Order...a climate reservation. :-)

Cyrus Slapatich : They are now, as we speak trying to find a way to pepper the atmosphere with Alka Seltzer.

Cyrus Slapatich : Despite all the half assed attempts to decrease emissions of CO2, they have increased instead. The earth's temperature has not increased in at least a dozen years. Global sea level rise has not happened either. That tells me that this is another Y2K money grabbing scam except way bigger.

JosephA W : The science was figured out over 100 years ago using math. Anyway cleaning up the mess we already made will create jobs. Every regulation creates jobs, like all the air quality test equipment and scubbers that have been installed in oil refineries. We in Los Angeles have seen incredible improvements in Air Quality and Sea Water Quality thanks to increased environmental concerns and activities.

Coke Supply : The reason for the temperature increase is that carbon dioxide molecules absorb infrared radiation at a particular wavelength and emit it at different wavelengths. The emitted radiation cannot pass back through the container at that wavelength, and so the heat accumulates. THIS EXPERIMENT DOES NOT PROVE THE ANTHROPOGENIC GLOBAL WARMING HYPOTHESIS. It merely demonstrates how plastic can be used as an alternative to glass when building greenhouses.

Wilbert Robichaud : Will it get warmer if you double the amount of Alka Seltzer?

Vooty13 : I like the graph comparing the two bottle temperatures. There is even a dip at about 40 minutes. Maybe that's the water absorbing heat from the warmer gas above it like the oceans absorb heat from the atmosphere?

Erik Christensen : Hi Emma., I used Alka-selzer tablets (generic versions work fine too). These are effervescent tablets to help with head and stomach aches. I am sure there must something similar in Australia - ask you local chemist. Cheers, Erik

Emma Lynch : Hi, I am a teacher from Australia and would like to know what exactly you put in the CO2 bottle. Thanks

SciCad : It would be more scientific to keep your responses direct, without ad hominum attacks (name calling). There needs to be a third bottle with co2 and a fourth with air that are kept in the dark. This demonstration doesn't account for either the build up in pressure or the heat of the dissolution of the tablet in the h2o. It would be even better if: 1. The concentration of co2 in the co2 bottle were actually measured; 2. Another 2 bottles were used that had the AD1750 concentrations of co2 in air.

64jcl : Why are so many people in denial about these CO2 experiments clearly showing that CO2 i a greenhouse gas. I have seen many videos here showing the same and the comments are so full of people with denial that the physics cant be believed. Do you believe 2+2=4 ? Well thats math. CO2 added to a container (or atmosphere) increase the temperature... thats just Physics.

Theo Collins : mitekillem Pressure allows heat to transfer faster? Where do you get that? Pressure may cause heat, but not nearly enough to raise the temperature of half a bottle of water by nine degrees. If so, every time you had Alka Seltzer. the water would be steaming hot. Noticed that?

Daniel Gregory : You realize that by adding the alka seltzer you increased the volume of the bottle, thus adding pressure to the mix. Pressure allows heat to transfer faster.

NoEcologyNoEconomy : Well done, but deniers will find some way to ignore this experiment. Something along the lines of "Rush sez the Earth ain't no plastic soda bottle!"

Chris Alemany : It's too bad you didn't leave the video going throughout and simply sped up the time on the video. I think it is interesting that you could already see the temp rising faster in the CO2 bottle even before he interrupted the video.

richiebogie : Thanks for posting this experiment. It would be interesting to see what would happen if you repeated this experiment but this time 1) use only enough alka seltzer to double current atmospheric CO2 from 390 parts per million to 780ppm (possibly in the year 2150) and 2) use a large open tub instead of a closed bottle to keep pressure same and see the effects of convection currents (if any)

jim morrisey : When you fill something up with a different gas, the gas will affect it. The pressure changes therefore the temperature changes.

Momo Chan : Thanks for the video!! Have a nice day!!