Why CO2 does not govern the earth's surface temperature

I like Laurence Krauss, Neil Degrasse Tyson, etc. on most science and skepticism issues, but they have been sucked into the CAGW vortex on climate. Krauss has a new youtube video that nicely exemplifies the problem:



Sorry, Prof Krauss, but you have not established your hidden tacit premise that CO2 governs the earth's surface temperature -- and neither has anyone else. In your response to the fifth misconception, you talk about the relevant process, but you do not mention -- perhaps you are not aware -- that there is almost no water vapor at the effective emission altitude because the air is so cold. That means IR radiation moves upward to outer space from that altitude much more readily than it moves downward to the surface. The effective emission altitude and temperature therefore reach new equilibrium levels to restore the earth's radiative energy balance, but the change at that altitude has almost no effect at the surface because the downward IR radiation is blocked by the far greater IR absorption of water vapor lower in the atmosphere.

This is the physics that the anti-CO2 AGW alarmists have got wrong, and why they don't understand that restoration of the earth's radiative equilibrium in the upper atmosphere as a result of increased CO2 need not have any measurable effect on temperature at the surface. Your blanket analogy is very apt and correct. But there are two main kinds of blanket -- water vapor and CO2 -- and the earth's surface is under ~40x more water vapor blankets than CO2 blankets. Crucially, the water vapor blankets can't change much, and none of them can go near the top of the stack of blankets. So if we think of the pre-fossil-fuel earth's surface as being under a stack of 10 "greenhouse-gas" blankets, seven of the bottom 8 were water vapor, and then there were 2 CO2 blankets on top. Now if each CO2 blanket is doubled, the effect at the top will be to significantly warm the first 2 of the now-4 CO2 blankets at the top, restoring the radiative equilibrium. The top CO2 blanket will be very slightly cooler than the previous top CO2 blanket, but the one below will be warmer than the previous top one was. However, there will obviously be little effect on temperature at the bottom of the stack because the insulating effect of all the water vapor blankets is far too great to permit much of the temperature change that occurs at the top to propagate all the way down to the bottom.

 

An oldie but a goodie.

• Carbon Dioxide or Solar Forcing?

". . . Using historic variations in climate and the cosmic ray flux, one can actually quantify empirically the relation between cosmic ray flux variations and global temperature change, and estimate the solar contribution to the 20th century warming. This contribution comes out to be 0.5±0.2°C out of the observed 0.6±0.2°C global warming (Shaviv, 2005).

Fig. 5: Solar activity over the past several centuries can be reconstructed using different proxies. These reconstructions demonstrate that 20th century activity is unparalleled over the past 600 years (previously high solar activity took place around 1000 years ago, and 8000 yrs ago). Specifically, we see sunspots and 10Be. The latter is formed in the atmosphere by ~1GeV cosmic rays, which are modulated by the solar wind (stronger solar wind → less galactic cosmic rays → less 10Be production). Note that both proxies do not capture the decrease in the high energy cosmic rays that took place since the 1970's, but which the ion chamber data does (see fig. 6). (image source: Wikipedia)

Fig. 6: The flux of cosmic rays reaching Earth, as measured by ion chambers. Red line - annual averages, Blue line - 11 yr moving average. Note that ion chambers are sensitive to particles at relatively high energy (several 10's of GeV, which is higher than the energies responsible for the atmospheric ionization [~10 GeV], and much higher than the energies responsible for the 10Be production [~1 GeV]). Plot redrawn using data from Ahluwalia (1997). Moreover, the decrease in high energy cosmic rays since the 1970's is less pronounced in low energy proxies of solar activity, implying that cosmogenic isotopes (such as 10Be) or direct solar activity proxies (e.g., sun spots, aa index, etc) are less accurate in quantifying the solar → cosmic ray → climate link and its contribution to 20th century global warming. . . . "

 

... because CO2 is not God and CO2 (being a colder gas) cannot heat Earth's surface (a warmer surface).

Source: 2nd Law of Thermodynamics

 

In a cold room, your body is warmer than a blanket, but the blanket can make your body even warmer.

 

Incorrect. A blanket does not "warm" one's body at all. Try it out for yourself... put a blanket on top of a rock or a lizard and see if the rock or the lizard becomes any warmer...

Instead, it is one's own body that "warms" one's own body, as one's own body is in and of itself a thermal energy source. The blanket is simply acting as a coupling reducer, reducing the coupling between the colder outside air and the warmer "trapped" air underneath the blanket. This allows the body to easier keep itself warm when colder air is surrounding it. This is also why hats and jackets and etc are useful during cold Wisconsin winters, for example...

 

The Earth's surface is a thermal energy source. (Actually the source is the Earth's interior, but you get the idea.)

 

And if you can get a cat to sit on your chest , under the blanket, it feels even warmer. But it will not get warmer than internal temp. .... ever.

 

The source is the sun. In the blanket analogy, the source is food. Just as CO2 does not stop incident (mostly visible-spectrum) solar radiation from reaching the earth's surface but blocks the outgoing IR radiation (which the earth's surface converts the visible light into), the blanket does not stop your food intake, but blocks the outgoing heat that your body converts the food into.

 

The sun warms the atmosphere and oceans. The Earth generates its own geothermal heat as well.

 

I am of course objectively correct.

Yes, of course it does. That is why people buy blankets. Your claims are just objectively false. You'll find that happening a lot, as long as you presume to dispute with me.

The rock will not become warmer because there is no energy source. However, the lizard will become warmer because its metabolism releases heat energy that the blanket holds it. You may sometimes see people who have pet iguanas putting sweaters on them to keep them more active when it is cold.

Food is the body's energy source. Just as the blanket does not impede your intake of food, CO2 does not impede the visible-spectrum light energy that the sun pours onto the earth's surface. Your body absorbs your food and converts its energy into heat, which the blanket then traps, just as the earth's surface absorbs visible light and converts it into IR radiation that CO2 (and water vapor, and a few other trace gases) then traps.

Just as "greenhouse" gases like water vapor and CO2 reduce the radiative coupling between the earth's warm surface and the cold of outer space.

Much as greenhouse gases help keep the earth's surface from being as cold as the moon's surface.

And the surface of Mars is warmer than the surface of its moons.

 

The sun also heats the earth's solid surface. Internal geothermal heat is a microscopic fraction of the earth's energy balance.

 

But >0.

 

Sure. Just as radioactive decay (which is the source of the earth's geothermal energy) contributes to your body's heat. We just ignore it and focus on food, for much the same reasons we ignore the geothermal component and focus on the sun when analyzing the earth's energy budget.

 

Yes. I'm not sure what we're debating.

 

gfm's false claim that cold CO2 can't warm the earth because of the Second Law of Thermodynamics. The Second Law applies to closed systems. The earth is not a closed system.

 

I don't dispute that.

 

Correct, as you are speaking of geothermal energy, but it is ultimately the Sun that heats the Earth.

 

My claim was completely accurate.

Correct.

Yes, it is. A closed system is simply any system that has defined boundaries.

Earth is a closed system. However, if one is using Earth as their system, then one cannot later make reference to the Sun, since the Sun is outside of the defined boundaries of the Earth system.

In such discussions, I will always refer to what I call the Sun-Earth-Space system, also a closed system (since it has defined boundaries).


The 2nd LoT applies, and colder CO2 cannot heat the warmer surface of Earth. You just wish to deny science in favor of your wacky religion.

 

CO2 is not a magick one-way blanket...

 

The cat is providing additional thermal energy within the trapped air underneath the blanket.

 

No, you are dead wrong, and are denying science in favor of your religious beliefs.

Argument of the Stone Fallacy.

I already explained to you how blankets work. Blankets do NOT warm one's body at all. One's own body is what is doing the warming, NOT the blanket. One's own body is a thermal energy source. A blanket is NOT a thermal energy source. You are just plain dead wrong about this.

PRECISELY my point, and PRECISELY why I am correct and you are wrong, yet you are trying to claim that I am wrong.

Lizards are cold blooded. They are not thermal energy sources.

Correct.

CO2 is not food. CO2 is not a blanket.

WRONG. The body converts food into thermal energy, NOT heat.

It is not possible to trap heat. What gets "trapped" in the blanket scenario is air, not heat.

CO2 cannot trap heat. And this is also where you deny the Stefan Boltzmann Law, because if Earth's radiance were to be decreased (due to "trapping heat", as you claim), then Earth's temperature would actually be COLDER, NOT warmer, as temperature is proportional to radiance, per the Stefan Boltzmann Law. Like I said, you deny science in favor of your religious beliefs.

There is no such thing as "greenhouse gases", and CO2 is not a magick one-way blanket.

The presence of an atmosphere does not warm a planet. The atmosphere IS part of the planet. All the atmosphere does is tone down drastic temperature swings, as are seen on the moon and on the ISS. It is the SUN that warms a planet.

The temperature of the surface of Mars (and its moons) is unknown.

 

Yes.

 

I'm guessing you have no science education past high school, if that.

Wrong again.

No, I explained it to you.

Self-evidently false.

Yet one is warmer with the blanket than without. Such a mystery. To you, that is.

I am objectively correct. The blanket is not the source of the energy, but it does warm your body by preventing dissipation of the heat the body produces.

You ARE wrong.

Let me guess: you voted for Trump, right?

Any living organism is a thermal energy source. That really is an implication of the Second Law of Thermodynamics. Lizards' bodies are warmer than the surrounding air. They are called "cold-blooded" because they just don't regulate their body temperature as birds and mammals do.

It is plant food.

It has a similar effect on the earth's surface temperature as a blanket has on one's skin temperature.

What do you think "thermal" means??

Google "thermal insulation" and start reading.

Wrong again. Both are trapped by a blanket, as it reduces conduction, blocks convection, and is opaque to most infrared radiation.

It can and does, by absorbing and re-radiating infrared radiation.

<sigh> Where to begin? First, the Stephan-Boltzmann Law describes the effect of temperature on radiance, not vice versa. Strike One.

Second, the law applies to the effective thermal emission layer of a planet's atmosphere, not the temperature of its surface. Strike Two.

And third, it applies to black bodies, and the earth is not a black body. One of the complicating factors in CO2's role in determining the earth's surface temperature is the fact that water vapor and CO2 are more efficient infrared radiators than nitrogen or oxygen in the relevant wavelengths, but there is very little water vapor at the effective emission altitude, so CO2 is far more important in the effective emission spectrum than in the surface temperature regime.

That's Strike Three, Casey. You're out.

It's true that "greenhouse gas" is a misnomer, as greenhouses work by blocking convection, not radiation. Completely different mechanisms.

There is nothing magical about the fact that CO2 and water vapor are transparent to the visible wavelengths that dominate incident solar radiation, but opaque to much of the re-radiated thermal radiation -- i.e., that it does indeed function a bit like a one-way mirror.

It warms the surface in accordance with the Combined Gas Law, regardless of any so-called "greenhouse effect" on infrared radiation. That is why Venus is hotter than Mercury at its surface, the earth's surface is warmer than the moon's, and Mars's surface is warmer than its moons'.

Right: the part above the solid surface. That seems to have confused you a lot.

False. The average is much higher on the earth's surface than on the moon's, even though they are the same distance from the sun.

Then why is the surface of Venus warmer than that of Mercury?

No, it is not. It can be and is measured by their IR radiation spectra.

 

There is nothing magical about the fact that like water vapor, CO2 is transparent to the visible wavelengths that warm the earth, but opaque to the infrared wavelengths that cool it.

 

It was false.

The earth does not have such boundaries, as it receives energy from the sun. It is therefore not a closed system. You are objectively wrong. You will find that happening a lot, as long as you presume to dispute with me.

Conclusively refuted above.

If you are not talking about the sun, you are not talking about what determines the earth's surface temperature. It is that simple.

Then your claim about CO2 and the earth's temperature is still wrong, because it treats the earth as a closed system when it is just an element in the Sun-Earth-Space system.

False, as already proved.

Silliness. I haven't mentioned any religion or religious belief. It is you who are denying science, as I have proved repeatedly. Now, you can choose to either go on denying science, or find a willingness to learn some science from someone who self-evidently knows incomparably more of it than you.