Merchants of Doubt had Hansen again repeat his nonsensical assertion that the high temperatures on Venus are due to the greenhouse effect. This is mindless mythological nonsense started by Sagan and constantly repeated by clueless climate scientists
Venus surface goes for months at a time without receiving any sunlight (due to very slow rotation on its axis) yet the temperature does not drop more than a few degrees. How can a “greenhouse” operate without any sunlight? The whole point of a greenhouse gas is that it allows SW solar radiation to pass, but blocks LW radiation.
Equally as damning is that the dry lapse rate on Earth is similar to Venus, and that it is unaffected by humidity.
When a mass of air is lifted, it cools at the dry adiabatic lapse rate of 5 1/2°F per 1,000 feet as long as it remains unsaturated (relative humidity below 100 percent).
Air at 99% humidity has ~99 times as much greenhouse gas as air at 1% humidity, yet the lapse rate is the same. It obviously has nothing to do with the greenhouse effect. The temperature at the surface is primarily controlled by the height of the troposphere. Temperature and volume are the only two degrees of freedom in the Ideal gas law. PV = nRT
Atmospheric pressure is fixed by the weight of the atmosphere . That doesn’t change. Similarly, n is fixed. R is a constant. The only degrees of freedom are V (determined by height of the troposphere) and T.
During the winter, the height of the troposphere decreases and temperature drops. During summer, the height of the troposphere increases and the temperature increases. If n increased (say due to volcanic activity) then P and V would also increase and T would rise proportional to the increase in number of molecules.
Venus is hot because it has a very tall, high pressure troposphere. If Earth didn’t have oceans and limestone, it would be extremely hot here for the same reason.
As long as the height of the troposphere remains relatively fixed, the temperature on Earth won’t change tremendously. If the Sun suddenly went out, the troposphere would collapse and so would temperatures.
These idiots act as if man invented CO2 and the greenhouse effect. Well, OK, maybe the greenhouse effect. 😉
Don’t say stuff like this on Littlt Green Footballs you get banned.
Absolutely correct!! This basic college level chemistry and physics and yet the so called “climate scientists” can’t grasp the basic concepts of science in their fabricated models. Apparently they can’t see the forest for the trees.
By mass the Martian atmosphere has more CO2 than Earth, and a similar percentage to Venus.
http://solarsystem.nasa.gov/planets/index.cfm
http://www.crh.noaa.gov/fsd/?n=planet
http://atmos.pds.nasa.gov/
Parts of the atmosphere of Uranus are in the dark for 24 straight years. The night time atmospheric lapse rate must be the same as it is on the daylight side. since otherwise the atmosphere would not be stable. Perhaps there are some measurements of its lapse rate somewhere.
The fact that the troposphere can change height at all is a significant factor that most “Greenhouse Effect” advocates completely ignore. In an actual greenhouse, warm moist air will rise until it hits a sheet of glass, and there it must stop rising (always at exactly the same place). However in a planetary atmosphere warm moist air will continue rising (H2O is lighter than air) and will not meet any sheet of glass, it will rise until it cools and condenses, end of story. Thus, the height of the troposphere is whatever height it needs to be in order to lose the heat. There is no way to trap heat in this scenario.
During summer, the sun is delivering more energy, so the height of the troposphere increases to accommodate a mechanism to dump that energy. In winter there isn’t as much input energy, so the height of the troposphere decreases because you don’t have as much warm moist air rising during winter.
Now, take note that the Earth is a ball (not flat). What happens to the surface area of a ball when the radius increases? Oh, the surface area also increases, which means the available surface for radiation of heat into space increases… this heat sink will be whatever size it needs to be, in order to radiate away the heat, and it constantly adjusts based on the behaviour of the water molecule rising until it cools and condenses. The only time we could have a “runaway” situation is if the oceans boiled dry.
CO2 adds mass to the atmosphere, but on Earth that’s a very small mass, so yes that must slightly increase the surface temperature by the gas equation but the amount would be tiny.
Does CO2 reduce the efficiency with which the surface can lose heat (thus forcing the troposphere height to increase as compensation), again the answer is yes but the effect is tiny. Convection is by far the more powerful heat carrying mechanism. Convection plus water is what keeps the Earth at a stable temperature.
I was gathering from Tony’s article that Troposphere height was a controlling/initiating factor and that didn’t sound right. From your post I read that the height is a result of the controlling factor of solar input/variability. That’s what I recall from my past science courses.
I understand the PV=nRT issue. What I also remember is that if you turn up the flame the mass gets warmer and T or P or V (or a combination) increases, which is what you state in your post. Gravity affects the PV part of the equation. So I would suggest that gravity and solar input are the controlling factors holding other things like vulcanism constant.
While converting solid CO2 into gaseous CO2 will increase the mass of the atmosphere, as others have stated, I really find it difficult to believe a trace gas mass change can ratchet up the temperature like the ‘experts’ claim. With no ‘ceiling’ on the atmosphere I do not see any ‘greenhouse’ and consider that whole thing to be a bunch of cod’s wallop.
Oh yeah… and where’s the mid tropospheric hot spot that GHE demands exist?? I’m still looking for it. Perhaps it too is hiding in the deep oceans along with the ‘hidden’ heat?? ha ha.
“….and where’s the mid tropospheric [tropical] hot spot that GHE demands exist?? “
Blizzard at Manua loa and Blizard in Mexico City (Lat 19N)
I was yanking Hopeless around over that mid tropospheric tropical hot spot last night and as expected it flew right over her empty head.
Keep up the good work Gail! I love it when you guys with quicker wits than mine take on the buffoons and ‘true believers’ of any of the various quack belief systems like AGW and Marxist redistribution economics, etc.
That is why this site is so much more fun compared to WUWT. A night at the opera vs a good time at the local pub. I prefer the pub even though I am always the designated driver.
If you do the math out doubling CO2 from 400 ppmv to 800 ppmv decreases the atmosphere’s gas constant (R) by 0.07 J/kg°K and increases its density by around 0.00075 kg/m³ and pressure by a proportional amount. That is if you assume the extra CO2 displaces all the other gases in proportion. It actually works out lowering equilibrium temp by .08°K if my back of the envelope calcs are correct.
Venus has 87,000,000 times more CO2 than Earth. That’s only 18 doublings. Even at 3 degrees of climate sensitivity per doubling, Venus should only be 54 degrees warmer than Earth. Here are the 18 doublings.
400 ppm
800
1600
3200
6400
12800
25600
51200
100 k
200 k
400 k
800 k
1.6 m
3,2 m
6.4 m
12.8 m
25 m
50 m
100 m
It’s not the CO2, stupid.
Either that Morgan, or the next time I eat bean burritos the planet’s temperature should jump up about 10 degrees, ha ha. I believe Venus’ surface temperature is around 450 degrees (?). That would put the sensitivity at around 22 degrees per doubling. ha ha ha ha ha ha. Yeah. Sure.
Now that is a really great point. Thanks
They say the absorption band widens for increased CO2 levels but I have not yet seen any science paper addressing the 18 doublings. I don’t think anybody knows about it.
My hp15C says 26.37 doublings, not 18: (log(87meg)/log(2)); yielding ~79 degrees. But what do I know, just an Engineer!
To my thinking, the above would be correct if the globe was a circle.
From sunrise, atmospheric pressure drops, to rise again after sunset. So the half that’s receiving sunlight experiences decreased pressure, increased volume and increased temperature. The other half increased p, decreased V and T.
Averaged to a flat circle (as the climate fraudsters do) it can be said that pressure is fixed, but we don’t live in averages.
IMHO
p would not change