Tales From The Travels

I have engaged in an exchange of comments about global warming on a previous post of mine about a greenhouse gases experiment I designed.

I decided to consider these posts as the second entry into my $1000 Global Warming Skeptic Challenge. All of the comments, and my replies, are copied below. My critique of validity of his argument is included at the end. I’ll save the suspense, he failed to prove his point. But, then again, no other global warming skeptic has ever been able to prove it, either.

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Skeptic:
The atmospheric greenhouse effect assumes that in daytime, a cool atmosphere “back radiates” to a warmer earth surface. While all bodies radiate, the nett effect can only be heat passing from warm bodies to cooler bodies – 2nd Law of Thermodynamics.
This NASA diagram shows no greenhouse :

http://eosweb.larc.nasa.gov/EDDOCS/images/Erb/components2.gif

My view is that the atmosphere acts like a radiation shield on an automotive exhaust. One or more sheets of metal between the hot exhaust and cool surroundings, reduce radiation from the hot exhaust. The shield(s) adopt intermediate temperatures. There is no “greehouse effect” between the shield and the cool surroundings.
The result is that absorption of sunlight by gases in the atmosphere, moderates daytime temperatures. Similarly it increases nightime temperatures.
It would be interesting to see a trend of the difference between global average max and min temperatures over the past 150 years. If GHGs are increasing, one would expect a falling trend. This trend would be less susceptible to urban heat island effect. Is this data available ? (It is obviously stored in order to calculate global average temps).
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Me:
You’re wrong when you say the diagram does not show any greenhouse effect. There is an arrow labled ‘Radiation Absorbed By Atmosphere 15%’. Atmospheric absorption is what the greenhouse effect is all about, and what this experiment is all about. The experiment shows that a CO2 atmosphere absorbs more energy than a N2O2 one.
As for the day/night difference, that is an interesting question. You could be correct on this, although I have some thoughts about it. It would depend on the relationship of energy escape rate at night versus energy storage rate during the day. I don’t know where to find that data, but I agree with you that it should be somewhere.
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Skeptic:
Correct … the diagram does show heat from sunlight being absorbed. I have no argument about the atmosphere absorbing incoming solar radiation. However, it does not show greenhouse “back radiation” (that is, a cool atmosphere radiating heat to a warmer earth) as most of these heat/energy “greenhouse” diagrams do.
I suspect that there is a general confusion about heat / wavelength / temperature. The 2nd Law doesn’t care what the wavelength of the energy is. The idea that a cool atmosphere can absorb long wavelength radiation from the earth and then “back radiate” this to a warm earth violates the 2nd Law.
As you and the diagram suggest, all the atmosphere does during daytime, is to absorb some incoming solar radiation.
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Me:
Your statements about greenhouse effect and the 2nd law are both incorrect.
The 2nd law of thermodynamics says, in various forms, that entropy always increases. Heat can, and does, move from a cool body to a warm body, as long as there is an increase in entropy somewhere else to compensate.
But, that isn’t what the greenhouse effect is all about. What the greenhouse effect says is that the atmosphere is trapping heat, like a blanket on a bed, and keeping the overall temperature higher than it otherwise would be. By adding more greenhouse gases to the atmosphere, the atmosphere becomes more efficient at trapping heat. Individual molecules will trap heat, then reradiate them. But, there is not a preferred direction to this radiation. Energy will be radiated by the molecules in all directions. Some of this radiation will be reabsorbed by the ground, some will be reabsorbed by other molecules in the atmosphere, and some will radiate into space.
There is certainly no violation of the laws of thermodynamics there.
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Skeptic:
Yes, the general expression of the 2nd Law is that there is always a tendency to an increase in total entropy. In a simple system such as this, assuming constant pressure, perhaps you can give an example of heat flowing from a cold body to a hot body without the input of work ?
Have you discovered a source of perpetual energy ?
If the greenhouse effect acts “like a blanket on a bed, and keeping the overall temperature higher than it otherwise would be” as you suggest, we would expect temperatures to be lower in daytime if there was less GH gases. This is exactly the situation over deserts, with low levels of water vapour in the atmosphere … but deserts are hot in the day, not cool. The only NETT effect that GH gases have is to absorb incoming solar radiation, as shown in the NASA diagram. There can be no NETT back radiation from a cool atmosphere to a warmer earth.
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Me:
Again, you are wrong on several counts.
First, there is work being done on the Earth by the Sun, a huge amount, in fact.
Second, the Earth’s environment is certainly not a simple system. There is nothing that is simple about it. If it was, things like weather forecasting would have been perfected long ago.
Third, being a desert does not mean it is hot. Antarctica is considered the driest desert in the world. A desert such as the Sahara is hot because of the intense solar radiation during the day is absorbed by the ground and not by ground cover. Plant life converts much of this radiation into chemical products through photosynthesis. More energy is used up in evaporation. Without ground cover and without the evaporation that would be found in a wetter climate, the ground absorbs all of the heat and then reradiates it. After sunset, the ground is no longer receiving solar radiation and cools rapidly. This daily cycle has nothing to do with the greenhouse effect or global warming. What you would need to do is to check the long-term average temperature in a desert to see if there is any change. The data shows that, yes, even the desert areas are getting hotter.
Also, the atmosphere is typically only cooler than the ground during the daytime, but warmer during the night.
As for the net effect, your statement is correct, but misleading. It is true that eventually, all energy coming into the atmosphere will leave it. But, this could take thousands of years, or even millions. If energy is trapped in the atmosphere at a rate greater than what it radiates back out into space, then the temperature must rise.
By the way, referring to your comments about radiating from a cool system to a hot one, you must take into consideration the atmosphere. The upper levels of the atmosphere are much hotter than the lower ones. Temperature drops as you go up in altitude, but then rises again to temperatures in the 100s and even 1000s of degrees. By your argument, we could never radiate any heat into space at all because it would first have to radiate through this much hotter layer of the atmosphere.
If you think that global warming is false, then I suggest you check into my $1000 Global Warming Skeptic Challenge. If you can prove, via the scientific method, that global warming does not exist, I’ll pay you $1000.
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Skeptic:
Are you now suggesting that the work done by the sun on the earth is responsible for heat travelling from a cold bodies to hot bodies ?

You did not answer my question:
… assuming constant pressure, perhaps you can give an example of heat flowing from a cold body to a hot body without the input of work ?

I have no argument that the earth\’s atmosphere and climate is complex. The discussion here relates to the claimed \”greenhouse effect\” … that is, the daytime \”back-radiation\” from so called GHGs.

Once again you have sidestepped … your greenhouse theory would suggest that the daytime Sahara temperatures should be cool rather than hot, because of low levels of the major GHG, water vapour. Low GHG\’s mean what you call your \”blanket\” is missing.

\”As for the net effect, your statement is correct\” … we are making progress !

Do you disagree with this NASA diagram showing no \”back radiation\”, no greenhouse effect, and no what you refer to as \”a blanket\” ? :

http://eosweb.larc.nasa.gov/EDDOCS/images/Erb/components2.gif

The atmosphere is not opaque as you imply. Warm parts of the atmosphere will show a nett radiation to cooler parts. However the atmosphere does not absorb all radiation passing through it. It is partially transparent … that\’s why even in very polluted areas we can see the sun.

Your $1000 is very \”old hat\” and looks very silly compared to the $500,000 offered here :

http://www.ultimateglobalwarmingchallenge.com/

… if you can prove global warming is true.

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Skeptic:
I should add that the sign of a good scientist is that he is a skeptic about just about everything. History is full of examples of great scientists who have stood against the tide of popular opinion. Galilleo is a good example, although he waited till his death bed before standing for the truth. Bruno was a little more bold and was burnt to death as a result. John Nash didn\’t want to be \”contaminated\” by ideas of others, so he derived everything himself from first principles.

Most scientists probably had similar experiences to mine years ago when I first heard about CO2. I\’d learnt 350ppm in school and now it was higher … at first glance it seemed there might be a connection with global temperatures. However it didn\’t take a great deal of investigation to start to see the flaws in the hypothesis. Until a couple of weeks ago, I\’d taken greenhouse for granted, as I\’m sure 99% of other scientists do. I may have made similar statements as the blogger here. On questioning greenhouse in detail, it is clearly built on just as poor grounds as the theory about man\’s CO2 causing global warming.

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My critique of this entry:

I believe you have a fundamental misunderstanding of thermodynamics in general, and the 2nd law in particular.

As I understand it, you say that global warming is not valid because heat cannot go from the ‘cooler’ atmosphere to the ‘hotter’ ground. This is wrong on two points. First, the atmosphere is only cooler during the day, but is warmer at night. By your very reasoning, heat is flowing one way during the day, but in the reverse direction at night.

But, even this is incorrect. Heat is not a substance that flows only one way at a time. Heat is energy and is flowing in all directions simultaneously. As the ground radiates heat, it is absorbed by the atmosphere. The atmosphere then reradiates it out. The ground and the atmosphere both reradiate it in all directions and they do so simultaneously. So, while heat is moving from the ground into the atmosphere (and, also down into deeper ground), it is also moving, at the same time, from the atmosphere back into the ground (as well as into other parts of the atmosphere and even into space). This is not only allowed by the 2nd law, it is required by it. You wanted me to provide an instance when “assuming constant pressure, perhaps you can give an example of heat flowing from a cold body to a hot body without the input of work ?” In fact, this is what is happening with every cold body that is in contact with a warmer body. A glass of ice tea is radiating heat into the hot atmosphere around it, even while the atmosphere is radiating heat into the ice tea.

This is the way everything works. As you sit there reading this response, you are radiating heat out into your surroundings. Those surroundings, in turn, are reradiating that energy. Some of that energy being reradiated will come back to you. Now, if one object is hotter than the other, there will be a net transfer of energy from one to the other. In the absence of a third source, the hotter object will be getting cooler and the cooler object will be getting warmer. This is different than saying there is only heat moving one way. For instance, if you give me $10 and I give you $9, there is a net transfer of money, but money is also being transferred both ways. In the event there is no net transfer of heat between two objects, the two objects are said to be in thermal equilibrium. But, even in equilibrium, energy is being constantly exchanged between the two systems.

But, even this doesn’t explain everything. That’s because there is a third party involved here, the Sun. The Sun is transferring energy to the Earth and causing heating. Some of this energy is absorbed by the atmosphere and never makes it to the ground. I never made any comments about the atmosphere being opaque, but the fact is, the atmosphere is opaque to many frequencies. The fact that it isn’t opaque to all frequencies is obvious. We wouldn’t be able to see anything if it was. So, some frequencies must be getting through.

However, the ground is opaque to these frequencies and absorbs them. This causes the ground to heat up. Even as the ground radiates this heat in a process that is working to cool it down, more energy is coming in from the Sun to continue to heat it up.

If there were no atmosphere in the way, the energy radiated outwards by the ground would go directly into space. For instance, the Moon and Mercury both have little to no atmosphere and we see this process at work. The surface of these bodies heats up tremendously in the direct sunlight, but then cools precipitously when the Sun is not shining on it. As a consequence, the Moon and Mercury both have extreme temperature ranges between day and night.

Add an atmosphere and we see something different. Mars, which has only 1/100th as much atmosphere as Earth, does not have as pronounced a temperature swing. Even this thin atmosphere (mostly carbon dioxide) provides insulation to the surface to keep the heat from radiating directly into space. Some is absorbed by the atmosphere and reradiates it in all directions, including sending some back towards the ground. As a consequence, the heat cannot leave Mars as quickly as it does on the Moon and Mercury. This is basic insulation theory and exactly the way insulation in your house works.

On Venus, the atmosphere is 80 times as thick as ours, again mostly carbon dioxide. This thick atmosphere is such an effective insulator that there is no temperature variation on Venus at all. The temperature everywhere on the surface of Venus is the same – from day to night and from pole to pole.

The Earth’s atmosphere does exactly this, too. It prevents the ground from radiating heat directly into space. It absorbs some the heat radiated by the ground and then reradiates it in all directions. Some of that reradiated heat is absorbed by some of the surrounding air, and some is reabsorbed by the ground.

That is the greenhouse effect. I had a hard time following your last statement about the greenhouse effect. It appears that you may be saying there is no such thing. If so, it would be hard to have a discussion with you about the topic because you would have to reject all science to reach that conclusion. Individuals that take that stand typically sound like the creationists that reject the Copernican theory and say the Sun and planets revolve around the Earth because the Bible says so. So, I hope that isn’t what you’re stating in you last post shown above.

Global warming is a different than the greenhouse effect. What global warming is saying is that manmade emissions into the atmosphere are causing it to become a more effective insulator. As a consequence, more of the radiation emitted by the ground, and by the atmosphere itself, will be trapped and unable to escape to space. As long as the Sun continues to do work on the Earth and shine energy on it, there will be an energy input. More of this energy input will stay in the Earth-atmosphere system and cause the temperature to rise. Eventually, thermal equilibrium will be restored and the amount of energy radiating out into space will be equal to the amount coming in. But, the temperature will continue to rise until such a time as that equilibrium is reached. Of course, if we continue to put greenhouse gases into the atmosphere, we will continue to make it more difficult for the system to reach thermal equilibrium and the temperature will continue to rise.

As for the NASA diagram, this ‘back radiation,’ as you incorrectly call it, is included in the energy absorbed by the atmosphere. Notice, there is no time-lines on that diagram. All it says is that energy is absorbed by the atmosphere and eventually radiated into space. By this diagram, you can’t tell if it takes a second to accomplish this, or a million years. Also, please note that this is a simple outreach diagram designed to give a general idea of the processes at work and is not designed to be scientifically rigorous. Also note, the amount of change that global warming will cause in the stated process percentages is so insignificant as to not show up in something this simple. If the percentage change was significant enough to show up here, we would have been incinerated long ago.

Stating that a good scientist is skeptical is not a valid argument. From what I can tell, what you are attempting to say is that by being skeptical, it makes you a good scientist. Of course, there is much more to being a good scientist than being skeptical. A big part of being a good scientist is knowing what things to be skeptical about. A good scientist roots himself in the fundamental laws of science and progresses from there.

Citing Galileo is not accurate, in a number of ways, nor valid. First, Galileo did not wait until his deathbed to come out with his theories. I suspect you are thinking of Copernicus, but even that is inaccurate. It is true that Copernicus received the first copy of his book on the day he died, but he had taught his theories in Church colleges and even at the Vatican, for years. Galileo, on the other hand, had been teaching the Copernican system for many years before his death. This is what got him summoned before the Inquisition. Contrary to popular belief, he was not called before the Inquisition for teaching the Copernican theory. He was summoned because he defied the Inquisition’s orders to him to not teach the theory. This may sound like splitting hairs, but splitting hairs frequently means the difference between going free and being punished. In fact, many of the senior members of the Church believed in the Copernican theory and supported Galileo’s teachings. Galileo was a devout Catholic and had many friends in the senior leadership, including the Pope. But, by defying the Inquisition, he was defying Church authority and had to be punished.

Global warming skeptics like to cite Galileo. From my vantage point, it appears they are saying that if they wrap themselves in the cloak of Galileo, then they become the persecuted scientist that is standing for truth against an illogical world opinion. The biggest problem with this is that you have to be right first, and the global warming skeptics are unable to show they are right about anything. I renew my statement that no global warming skeptic can prove via the scientific method that global warming is not occurring.

Which brings me to the Ultimate Global Warming Challenge. I am well aware of this challenge and actually submitted an entry to it. I did not make my submission in the hope of winning $500,000. Everyone I have ever communicated with about this challenge is in agreement – Steve Miloy never had any intention of awarding that money. At best, he was only trying to get free publicity. At worst, he wanted to say, ‘See! I offered $500,000 if someone could prove global warming and no one could. This proves global warming doesn’t exist!’ But, of course, he never showed why any of the submissions failed to prove global warming. He just said they didn’t and that was it (which was allowed for in the contest rules). You can see my previous postings about this challenge and my submission here and here.

I, on the other hand, am fully prepared to pay $1000 to anyone that can prove global warming doesn’t exist. I find your comment to be very interesting. If my challenge is so ‘old hat’, why is it that no one has ever done it? If there is such a proof out there, all you have to do is copy it and submit it. There is no such thing as plagiarism of science. I can say ‘E=mc2’ and not have to worry about Einstein’s estate coming after me. If this is ‘old hat’, submit it and win $1000. Are you saying you couldn’t use an extra $1000?

In summary, as I understand your comments, you have tried to prove global warming doesn’t exist because it violates the 2nd law of thermodynamics. As we have seen, this claim is scientifically invalid and you do not win the challenge.

However, you are always welcome to try again. There is no entry fee.