Frequently Made Errors in Climate Science - The Greenhouse Effect - Comments

[Jeff Rosenbury]

Beause it is. The greater heat absorbed by lower albedo melts more ice and snow. lowering the albedo even more as bare (darker) spots develope.

Also often there develope pools of water in low spots and the albedo there is lowered too, compared to the ice under the bottom of the pool. Again, I challenge you to find any Postive Feedback as strong as the one happening NOW in Greenland's ice sheet.

While this is likely true for Greenland, it's not at all clear it's true for sea ice.

Brewster's angle (53º) is the angle where about half of light is reflected off the surface of water. This means that above 53º latitude, naively, the albedo of water is over 0.5. (It is far more complicated than that of course -- which is my point.) Since ice and snow's albedo ranges from 0.9 to 0.3, it is not clear water's albedo is lower than ice in the arctic -- even in the summer. (In the winter the albedo is irrelevant because there is effectively no incident sunlight.)

Meanwhile, the arctic area can still "see" the night sky at a 90º angle. Its emissivity remains and the area continues to emit longwave infrared radiation. The limitting factor on this is likely the ∆T⁴between the ground/sea and the night sky. Raising the temperature in the region raises the ∆T and gets that 4^th power emission bonus.

I want to make it clear I am not claiming this melting is a good thing. I'm just claiming it has been poorly studied. The arctic environment is probably the most fragile in the world. Given the large methane deposits in the tundra and oceans (clathrates) which even small temperature rises might release, there is cause for concern.

I can think of a number of things wrong with my model, the most obvious is that water (and arctic ice for that matter) is not flat. Waves will create a chop effect limiting the albedo gain due to the Brewster angle. The Brewster angle will change with the seasonal axial tilt. The atmosphere above the ice will have a large effect since waves incident at a low angle will travel through much more air. These conundrums are just off the top of my head. My point is that this is a complex subject and any positive feedback loop is at best not obvious.

But the idea that the albedo is of great concern in a region getting little sunlight seems oddly immune to logic. Global warming is a big enough problem without adherents practicing bad science and settling for confirming their bias.

 

[D H]

Brewster's angle (53º) is the angle where about half of light is reflected off the surface of water.

That is not what Brewster's angle is. Brewster's angle is the angle at which none of the p-polarized light is reflected. All of that light enters the water. Most of the s-polarized light also enters the water at this angle. At Brewster's angle, over 95% of the incident light on a flat air/water surface enters the water. Water is darker than fresh asphalt at this angle. Water is darker than fresh asphalt at most angles. It's not until the light rays become very close to parallel to the surface (84 degree angle of incidence) that more light is reflected than transmitted.

 

[mheslep]

Now hundreds or years of accumuated soot are being exposed - that drops the albedo from about 0.9 to 0.1 so a nine fold increase in the solar heating occurs - your will be hard pressed to find any more strong positive feed back than that...

I don't think soot (black carbon) is properly described as a feedback of any kind. Rather, soot acts independently of CO2 radiative effects, i.e. a direct driver, like methane or aerosols. That is, if more soot were sprayed on the Greenland ice sheet from, say, a volcanic eruption, the albedo would further decrease even if CO2 concentration suddenly reverted to preindustrial levels.

Forcings graphic from AR4:

 

[jim hardy]

Just a thought on clouds and the effect of water vapor

the effect of water vapor on convection is tremendous

with Molecular Weight of just 18 vs air's ~29 , water vapor makes moist air less dense so it rises,
and its enormous heat of vaporization affects lapse rate causing an awful lot moisture laden air to rise above most of the atmosphere's CO2

at 5km, around 16,000 ft, it's already above nearly half the atmosphere
and any decent thunderstorm has tops above 20,000 ft
hurricanes more like 50,000

Given that a hurricane removes something like 5 X 10^19 joules per day from the ocean (http://www.aoml.noaa.gov/hrd/tcfaq/D7.html),

Subject: D7) How much energy does a hurricane release?

Contributed by Chris Landsea (NHC)

Hurricanes can be thought of, to a first approximation, as a heat engine; obtaining its heat input from the warm, humid air over the tropical ocean, and releasing this heat through the condensation of water vapor into water droplets in deep thunderstorms of the eyewall and rainbands, then giving off a cold exhaust in the upper levels of the troposphere (~12 km/8 mi up)...
...
Method 1) - Total energy released through cloud/rain formation:

An average hurricane produces 1.5 cm/day (0.6 inches/day) of rain inside a circle of radius 665 km (360 n.mi) (Gray 1981). (More rain falls in the inner portion of hurricane around the eyewall, less in the outer rainbands.) Converting this to a volume of rain gives 2.1 x 1016 cm3/day. A cubic cm of rain weighs 1 gm. Using the latent heat of condensation, this amount of rain produced gives

5.2 x 10¹⁹ Joules/day or
6.0 x 10¹⁴ Watts.

If we just USWAG 70 hurricane days a year , ten storms at a week apiece,
that's 3.64 X 10 ²¹ joules
comparable to the heat content of Earth's whole inventory of air.

https://www.quora.com/What-is-the-total-heat-content-of-the-Earths-atmosphere-partitioned-between-its-various-layers

if this guy is in the ball park
http://www.ecd.bnl.gov/steve/pubs/HeatCapacity.pdf

16.7 watt years per square meter per degree
how many joules in that many watt-years ?

16.7 watts = 16.7 Joules/sec, X 60sec/min X 1440min/day X365.25 day/year = 5.27 X 10⁸ joules /year X 1 year
multiplied by Earth's area of pi X 12,742000^², 5.1 X 10 ¹⁴m² = 2.69 X 10²³ joules
our 3.64 X 10²¹ joules lifted by hurricanes is only 1.35 % of that number

aha
Sooo can i suggest
hurricanes don't cool the whole climate system very much
they just help convey heat from the tropics to the upper atmosphere
where it migrates to the poles and radiates away ?
While that amount of heat isn't very significant to the oceans
it's darn significant to the air, amounting to 73% of its heat capacity number
and that air is responsible for most of the thermal radiation

http://earthobservatory.nasa.gov/Features/EnergyBalance/page4.php][/PLAIN] The atmosphere radiates heat equivalent to 59 percent of incoming sunlight; the surface radiates only 12 percent. In other words, most solar heating happens at the surface, while most radiative cooling happens in the atmosphere. How does this reshuffling of energy between the surface and atmosphere happen?

I wish i were smart enough to work this in my head and ascribe numbers.

Thanks for reading ,

old jim

 

[DrStupid]

Point 5 states that

"Compressing a gas heats it, but won’t keep it hot. If the atmosphere were just a static layer of gases, only heated or cooled by conduction, it would all come to the same temperature."

Would pure heat conduction really result in the same adiabatic temperature gradient?

 

[Danielvr]

I wonder how all this figures in climate models.

This is a negligible effect - while it gets very hot deep inside the planet, this heat is not well conducted towards the surface, and contributes only a minuscule part of the heat the surface receives from the sun.
See here:
https://en.wikipedia.org/wiki/Earth's_internal_heat_budget

I read the third section above, "Black Body Earth", which speaks of an -18 degree equilibrium, but I don't think I understand. Does that or does that not account for this heat from within the planet? I don't think it does, or else there wouldn't be places on Earth where it gets even colder in Winter. Or, maybe those colder places can be explained by regional differences in heat conductivity of the planet's mantle and crust?

The equilibrium temperature is the uniform temperature the whole surface would need to have in order to reradiate the specified amount of energy. You can have places during winter, at high latitudes, or simply at night with lower temperatures, as long as there are places with higher temperatures elsewhere.
I.e., it has to be compared with the averaged global temperature, not with specific individual instances.

Bandersnatch, thanks kindly for answering my question!

Intuitively, I still find it hard to understand that we, living on the thin crust of the planet, get so little heat from within the endlessly more voluminous and blazingly hot mantle. Particularly because when you descend into a mine, it gets so much hotter so quickly (1 degree F per 70 feet of depth). You'd think that a lot of that energy would find its way to the surface and be dissipated through the oceans and the athmosphere.

Do you happen to know how warm (cold) Earth would be if there were no Sun? If 0 Kelvin is the absolute minimum and 287 Kelvin is the current average temperature on Earth's surface, I wonder how much that would be if we only had Earth's core as an energy source.

 

[Bandersnatch]

Intuitively, I still find it hard to understand

Intuition from other, physically similar setups can help you here. Consider what it means to be a good heat insulator.
For example, you're an Arctic explorer and it's -70 degrees centigrade outside. Yet, thanks to the many layers of good insulation, your internal body temperature is kept at the healthy 36.6 degrees. That's over a 100 K difference. The indication that the clothes you're wearing are a good insulator, is that it let's very little heat escape, and there's a large gradient of temperature as you get deeper inside.
This is the same for Earth's lithosphere, made largely of poorly-conducting silicates - if it were a good heat conductor, you wouldn't get an increase in temperature as you get down the mine - the surface temperature would be instead almost the same as that of the deeper layers. Which would incidentally cause the whole planet to cool very rapidly as that hot surface would radiate heat profusely.
Again, this is the same as with warm clothing - if you can feel your body temperature when you're touching the outer layers, then it ain't a good thing to wear in the winter.

Do you happen to know how warm (cold) Earth would be if there were no Sun? If 0 Kelvin is the absolute minimum and 287 Kelvin is the current average temperature on Earth's surface, I wonder how much that would be if we only had Earth's core as an energy source.

Putting a precise number on that is beyond my paygrade. What I can do is provide an approximation of the upper bound.
Take the Stefan-Boltzman law:
$P=\sigma T^4$
We know that for the current surface temperature of $T_1=300 K$ (the calculations are too simplified to worry about being imprecise), the power received from the sun and reradiated by the surface (approximated as a black body) is $P_1=1.7*10^{17} W$
The energy estimated to be leaving the surface after being conducted from deeper layers (i.e., the internal energy heating up the surface) each second is $P_2=4*10^{13}W$
By comparing $P_1/P_2$ we can get the temperature of a black body radiating with power equal to only the internal energy loss (at its current magnitude):
$\frac{P_1}{P_2}=\frac{T_1^4}{T_2^4}$
$T_2= T_1 \sqrt[4](\frac{P_2}{P_1})$
You plug in the numbers given above, and get the approximate temperature $T_2 = 36K$ or -237 degrees centigrade.
This in an upper bound, because without the Sun, you'd end up with a planet that is not constantly heated up by it, so it'd cool faster over its life, so by today it'd be losing even less heat that it does now. It's about right an answer if you were looking for a scenario where the Sun magically disappears today.

The atmosphere would probably not affect that temperature by much - at 36K most of the gasses would liquify or solidify, and the peak radiation would be shifted much farther into the infrared, so any greenhouse effects would be negligible.

 

[Danielvr]

Bandersnatch, thank you once more for an enlightening response! I'd never have guessed that the outer layer of our planet is such a good insulator (basalt and granite being pretty cool to the touch -- but not -237 centrigades cool, for which we have to thank the Sun).

 

[James38]

Thanks D H, I was not aware that was wrong. But I like the image, much clearer than most, so I've just added a note. (Is the curve wrong, or just the number? The peak seems to be in about the same place as in other images I found.)

I think the curve is useful and accurate enough. So I would suggest changing the number on the image, and changing the note to indicate what you did.
I see no reason to leave that uncorrected error.

 

[Reality Is Fake]

Hi @Reality Is Fake

I'm having a little trouble parsing your post, so correct me if I misunderstood your main point.

Space, despite being close to 0K in temperature, when treated as a heat sink, doesn't have an arbitrarily high capacity to remove heat. Since the only mode of heat transport is radiative, you're limited by the black body radiation (i.e., Stefan-Boltzman law). All the effects you mentioned - blowing air over a hot surface or evaporative cooling of water - are internal to the Earth-atmosphere system. They only serve to redistribute heat across the planet, but they can't remove any heat from the system. In the end, everything must leave via radiation.

I´m sorry if it´s hard to understand my writing, english is not my native language.
Of course all energy leaves as radiation and it leaves from the top of atmosphere. As far as I can see it doesn´t matter that the gas is distributing the heat by cooling the surface at any location to all the volume of the atmosphere. That is a process that maximize the atmospheres capacity to radiate to space.

Black body radiation is a beautiful concept and S-B law is the reason that we can use space as a heat sink. Because it defines the energy leaving the boundary of a system that transfers heat to the surroundings as an effect only depending on temperature. It is true for the transfer of heat no matter if it is in the state of radiation or heat as kinetic energy. It is used for heat transfer and thermic radiation.

Are you saying that if we consider an imaginary furnace transferring heat from a heat source to a gasmix like the atmosphere that surrounds the source, then we would need no isolating walls if it was surrounded by zero-degree vacuum?

Wouldn´t that make gravity the force preventing cooling?

As I see it, Earth doesn´t have any internal system above the surface that can be treated as an enclosure. The thing that defines an enclosure is that it has a boundary that is a surface or has surface-like properties that transfer heat by conduction. A boundary must be heated and then emit energy according to it´s temperature, and the transferred heat is dependant on temperature only. According to S-B law = P/A=σT1^4 and for graybodys the temperature for all parts is lowered by emissivity.

So, yes, all energy leaves by radiation. And, yes, according to S-B law that is valid for both thermic radiation and heat transfer in gasses, we can calculate the transfer from Earth to space as an optimal heat sink. That makes the atmosphere an added value of heat transfer to the surface, since there is no barrier that transfer by conduction at the boundary. And heat transfer is defined by S-B law only as a product of temperature, which makes it clear that the lower temperature of the atmosphere, only acts as a receiver of the energy from the surface. The temperature of the source is constant even if it transfers heat to a colder body, when in an open system without boundary. If we study the internal structure of Earth we see the difference to a closed system. Very little heat is transferred at the boundary, the Earth surface.

According to theory of heat transfer, the rate of transfer is defined by the difference in temperature, and it shrinks as the difference gets smaller. So that makes a transfer of energy from atmosphere to surface a violation of the concept black body and even more for grey body. It only happens in closed systems with boundarys that reflects a large fraction and conducts a small fraction to the surrounding outside. The gas transfers heat back to the source when the gas has reached an even temperature in the system. That is the opposite of the Earth surface and it´s atmosphere.

If you then put something in the way of the outgoing radiation, so that part of it gets reflected back to the surface, you end up raising the surface to a higher equilibrium temperature..

Only if the reflected radiation is hotter than the surface, hot as in higher energy radiation. And there is no reflection, the gasses absorb and emit, and that is a product of temperature only. Applying S-B for heat and radiation for absorbing gas gives a rate of heat transfer that adds up to much below 0 for the low atmosphere temperature and Earth surface. But we only need to apply it for heat gain in the gas, the Earth surface will not gain anything from the low temp.

In you example with the rock by a fire place - if you could modify the experiment to use close-circulation air supply, and ensure that the only way heat can leave the system is via radiation (and keep the radiative surface area the same etc.), then as soon as the system reaches thermal equilibrium you won't get any cooling from the air circulating inside.

And that would be a system that had an totally even temperature in the gas surrounding the heat source, which is thermal equilibrium. The opposite of what we observe in the atmosphere that has a very steep gradient from the surface and the average temperature of the whole volume is a lot less than the surface. According to S-B law there is no doubt that the transfer of heat goes in one direction only and that is towards a bottomless heat sink. The atmosphere is just a big lossy extension of surface area from 2 to 3 dimensions, even 4 dimensions as it spreads heat transfer in time, and it is a large addition to the capacity of transfer in relation to the energy absorbed from insolation by only half the surface of the earth.

As I wrote before, I´ve been thinking and reading a lot about this and it really is a problem in the way Earth temperature is approached in the greenhouse theory. There is a few things we can be sure of, that the sun can be treated as an almost perfect blackbody, the Earth is definatly a grey body, and that makes it clear that the laws for radiation, heat, effect and temperature is the only way that we can define the interaction. Those laws, that is applied in many ways in technology and very functional, says that the emitted energy from a planet like Earth heated by the sun, is a product of temperature only. The atmosphere heated by the Earth is a product of temperature only. Transfer of heat in the system has a rate that is equal to the difference in temperature and it is lower for a small difference. When temperature is equal in two bodys in contact, there is no transfer of heat between the bodys. Heat is never transferred from cold to hot and that is proven by S-B law that gives the rate of transfer.

Another interesting thing is that I always had a hard time visualizing Einsteins theory of relativity, E=mc^2, but the greenhouse theory solved that for me.

Since mass * speed of light is equal to energy, and speed of light is the definition of a photon, and earth´s energy that is equal to temperature which is a product of photons radiated from the sun, we can be absolutely sure of that added CO2 cannot heat the Earth when all other things is constant.

If E/m=c^2 and E=Temperature of the earth, then an increased mass in the atmosphere by added CO2 without solar insolation increasing, would result in an increased speed of light in the photon if Energy that is divided by mass is increased. Which we know is an absolute limit for speed, as calculated for macroscopic relations in space. This is because the source of energy is external and fixed in addition to c that is an upper limit. The only thing that changes is the mass, and that actually would result in a decrease in energy measured as lower temperature of earth. A very small decrease but still, it seems like the whole theory of an atmosphere heating anything as an added volume of low density mass with a low emissivity above the surface, is a direct violation of E=mc^2. And even more so, added CO2 to any calculation cannot change temperature without adding more energy from the source, that is our sun.

I have searched intensivly for a complete calculation with S-B law that shows heating from the icecold atmosphere, and have found none. It has to include all bodys, the sun, Earth and it´s atmosphere. And a calculation of radiation balance at any point has to relate to the source, the sun. I f CO2 heats the surface as the last passive body in the chain, then it has to heat the sun as well if it is true. But it is not necessary to go that far, we only need to apply S-B law for heat transfer that is valid for both kinetic energy and radiation, dependant on temperature only, and there is no question that it is a violation of the relationship between matter and energy.

That is also confirmed by observation of energy as temperature in the atmosphere, steep gradients an very low temperatures that is averaged much below surface, is the tell-tale sign of something acting cooling on the surface.

I was quite happy when I realized that I finally can visualize Einsteins theory in matter with radiation of photons and energy as temperature of mass.

I don´t want to come across as a sceptic of AGW, I´m just really trying to figure out how added mass of co2, without added energy from the source, can raise temperature by heat transfer from hot to cold? And basically, how can an atmosphere that is an added low density volume to the surface, warm the earth?
When the numbers add up wihout an atmosphere? And why do we treat water and air as warming in the atmosphere when we never use it in that way in daily life?

 

[jim hardy]

The net effect of the greenhouse gas is therefore to slow the transfer of heat into space. That is all that is meant by trapping in this context.

Once air reaches tropopause it's above most of the greenhouse gas so radiation has a shorter hop to make
Hurricanes can move something like 10^22 joules a year up there
http://www.aoml.noaa.gov/hrd/tcfaq/D7.html
ten twenty day storms in a season ? lately we're having more...

Is that a significant number ?

 

[haruspex]

Once air reaches tropopause it's above most of the greenhouse gas so radiation has a shorter hop to make

Sure, but that is the bit where it matters. Below that, convection carries the heat up.

 

[jim hardy]

Below that, convection carries the heat up.

A lot of it by water vapor.
If this number is good
http://www.superstrate.net/pv/illumination/irradiation.html

The solar energy irradiated to the Earth is 5.10²⁴ Joule per year.

it would seem that in short-circuiting the insulating layer, hurricanes and thunderstorms provide a goodly part of a 1% energy trim mechanism to keep the tropical oceans cool.

 

[Bandersnatch]

Sorry for the late response to my part of the conversation. I didn't want to make this a wall of quotes (and kinda hoped haruspex would take over my bit as well), but I couldn't figure out any other way to go about it. I'll try to summarise the crux of the issue as what I think it is first, and then address some of the particular misconceptions in the spoiler.

Of course all energy leaves as radiation and it leaves from the top of atmosphere. As far as I can see it doesn´t matter that the gas is distributing the heat by cooling the surface at any location to all the volume of the atmosphere. That is a process that maximize the atmospheres capacity to radiate to space.

The last sentence here seems to be the culprit here. You're seeing the atmosphere as an additional heat sink - i.e., the idea seems to be that since for a set amount of incoming radiation Z, surface radiates X energy to space, then if we add a medium that will remove extra Y energy from the surface, and carry it away where it will then escape into space, it should mean that we've added another sink, so that the energy escaping is X+Y, meaning the radiative emissions have to go down, meaning the equilibrium temperature at the surface must become lower.

The issues with this picture are:
- the atmosphere is for the most part not transparent to the outgoing radiation, so it can't just escape into space - it gets absorbed and reradiated in all directions, including downwards. The actual atmospheric window for escaping radiation is just about 40 W/m^2.
- the thermal heat transfer (conduction, convection, evaporation) from the surface is 1. small when compared with radiative transfer, and 2. ends up being reradiated in upper parts of the atmosphere, again including back to the surface.

This could still be a valid objection if the energy balance at the surface was a net removal of energy, and would require quantifying - if it hasn't been done many times already. E.g. see the following paper (with its inforgraphic reproduced below):
http://journals.ametsoc.org/doi/pdf/10.1175/2008BAMS2634.1

All that energy that was removed from the surface and then returned in the form of back radiation changes the energy balance at the surface so that there is more incoming energy Z, and the equilibrium has to change to increase radiation (or thermals, but their magnitude is secondary), meaning increase in temperature of the surface.

So, looking at the atmosphere as a heat sink is faulty reasoning - it is an insulator.

But all you really needed, in order to know that the atmosphere is raising the surface temperature, is to do the calculations for the blackbody equilibrium temperature for an airless barren planet at 1 AU around the Sun. Since that is lower than what we've got here, it is a clear indication that the atmosphere is responsible for raising the temp. All that remains is to figure out how (which the paper linked above does nicely).

I'll put the rest into spoilers, since it's all a bit tangent to the main issue, I believe.

Spoiler

Black body radiation is a beautiful concept and S-B law is the reason that we can use space as a heat sink. Because it defines the energy leaving the boundary of a system that transfers heat to the surroundings as an effect only depending on temperature. It is true for the transfer of heat no matter if it is in the state of radiation or heat as kinetic energy. It is used for heat transfer and thermic radiation.

The Stefan-Boltzman law concerns only radiative energy transfer from a black body. You can't use it for thermals.

According to theory of heat transfer, the rate of transfer is defined by the difference in temperature, and it shrinks as the difference gets smaller. So that makes a transfer of energy from atmosphere to surface a violation of the concept black body and even more for grey body.

No! The violation would be if there was colder atmosphere heating up hotter surface, whereas what we've got is the hot Sun heating up the surface.
When considering the Earth+atmosphere system, you don't get any NET heat flow inward. Heat is always flowing away from the hot source (surface) to colder surroundings (including space). But there is extra energy coming inward from the atmosphere that wouldn't be there without air, which means that the NET heat flow is lower and the equilibrium temperature at the surface has to self-adjust to re-emit that extra energy.

Another interesting thing is that I always had a hard time visualizing Einsteins theory of relativity, E=mc^2, but the greenhouse theory solved that for me.

You should forget everything you wrote about GR there and there on after, since it's completely misappropriated, and just wrong.
Forget about the c^2 in the equation, it's confusing you. It's just a unit conversion factor, and you can freely choose units in which it's equal to 1, so that all the equation says is that mass of a body at rest has some associated energy.
You're mostly talking about energy conservation anyway, which is not violated when putting CO2 into the atmosphere (because the mass was already there, only not in the atmosphere) nor when increasing temperature, because the system is not closed - i.e. the Sun provides energy. If you would design a rather implausibly good insulation system for the planet, you could raise its temperature as high as the temperature of the Sun's surface, and it wouldn't violate any conservation nor thermodynamic laws.
And yes, that means that a hotter Earth has more energy stored, i.e., is more 'massive', i.e., curves space-time more.

And a calculation of radiation balance at any point has to relate to the source, the sun. I f CO2 heats the surface as the last passive body in the chain, then it has to heat the sun as well if it is true.

Why would CO2 on Earth heat the Sun? It doesn't make any sense.

That is also confirmed by observation of energy as temperature in the atmosphere, steep gradients an very low temperatures that is averaged much below surface, is the tell-tale sign of something acting cooling on the surface.

No, that is a tell-tale sign of a good insulator.
This might be another significant issue - what you seem to consider 'cooling' is just heat transfer from hot to cold. Remember that we're talking about systems in thermal equilibrium with their surroundings, which include heat sinks and heat sources. In such a system there will always be temperature gradients, but this doesn't necessarily mean there is cooling.
E.g. if you put on a sweater in winter, a steep gradient from your skin to the air will set up. By your usage of the term, the sweater is 'cooling' your skin, because you're loosing heat through it.

For something to be cooling a body heated by an external source, it has to increase energy transfer from the body, so that more net heat is removed than without it, and the equilibrium temperature drops as a result.
E.g., if you put a radiator on your processor, it'll remove more energy by increasing surface area in contact with air, reducing its temperature - i.e. a cooling effect. Conversely, if you glue a block of fibreglass to the processor, it'll slow down heat transfer, heating it up. The second case will have a steeper temp gradient than the first, but it will be undoubtedly heating.

I might have skipped a few points, but this response is already way too bloated.

 

[jim hardy]

Much of that 80 watts of latent heat gets deposited above 80% of the greenhouse gas

where its transport mechanism changes from convection to radiation, both upward and downward of course,

i've not been able to figure whether they model it that way
Downward bound has to get back through the ghg layer., upward doesn'tfrom last page

Thus, the downwelling
LW flux exists as one of the principle uncertainties in
the global surface energy budget. (page 6)In our analysis, the biggest uncertainty and bias
comes from the downward longwave radiation. This
source of uncertainty is likely mainly from clouds. (page 10)

old jim

 

[mheslep]

I have seen that too many times, it stings my eyes. If the atmosphere would give 333W it would have to have an average temperature of 4√(333/0.0000000567)=276K
We can be very sure that it doesn`t.

Yes CO2 molecules radiate per Stephan-Boltzman law based on their own temperature like everything else, but the scattering of IR is a different phenomenon and is independent of the temperature of the gas. Think IR "mirror", though with an arbitrary angle of reflection. Yes mirrors have their own blackbody temperature as any IR thermometer will confirm, but this has nothing to do with the ongoing reflection of light, and changing the temperature of the mirror won't change its reflective properties.

http://scied.ucar.edu/carbon-dioxide-absorbs-and-re-emits-infrared-radiation

 

[haruspex]

Much of that 80 watts of latent heat gets deposited above 80% of the greenhouse gas
View attachment 103078where its transport mechanism changes from convection to radiation, both upward and downward of course,

View attachment 103079i've not been able to figure whether they model it that way
Downward bound has to get back through the ghg layer., upward doesn'tfrom last pageold jim

If I understand your reasoning, increased GHGs should just lead to a hotter tropopause. But as we know, the lapse rate represents the limit on the ability of convection to even out the temperature. So a hotter tropopause at the same altitude, or the same temperature tropopause at a greater altitude, means correspondingly hotter at ground level.

The uncertainties over clouds' affect on downward radiation do not invalidate the principle of the greenhouse effect, they merely make its strength hard to assess. Until such time as clouds are better understood, we must a) look at direct measurement and b) apply risk analysis.
Direct measurement from satellites shows a significant excess of incoming radiation - especially considering that for a stable temperature the net flow should be outwards.

 

[Bandersnatch]

The number of 161 hitting the Earth is ridicolous, we can measure it to 1000. Why use such a misleading number, of course you will get a conclusion that is way off.

-There is a night side
-Earth is not a circle but a sphere

 

[D H]

You placed the "GHG lives here" sticky at the wrong point in the picture, which might be why you are confused. The greenhouse gases "live" over on the right, and are already labeled greenhouse gases.

 

[jim hardy]

You placed the "GHG lives here" sticky at the wrong point in the picture, which might be why you are confused. The greenhouse gases "live" over on the right, and are already labeled greenhouse gases.

You didn't read my post
I was showing that latent heat provides a shortcut back out of the atmosphere bypassing greenhouse gasses for about 1% of total heat that made it to Earth's surface
because from reading that report i took away that they've modeled heat fluxes as either/or not morphing
over here on the right ghg should be down low where i drew it because unlike surface radiation, latent only has to traverse ~20% of the ghg which was the point of my pressure vs altitude chart

 

[Evo]

Closed pending moderation.

 

[D H]

Thread re-opened, after a massive cleanup. Let me know if it looks disjointed.

 

[Geoffw]

Is this thread still active?

I believe the Trenberth diagram mentioned here is misleading. The massive opposing long wave fluxes are in vacuo radiative potentials and do not represent surface losses or atmospheric gains by radiation.

Any comments?

 

[mheslep]

Is this thread still active?

I believe the Trenberth diagram mentioned here is misleading. The massive opposing long wave fluxes are in vacuo radiative potentials and do not represent surface losses or atmospheric gains by radiation.

Any comments?

Yes. At the surface, the outgoing long wave must be represent one or the other, escaping long wave or atmospheric heat gain. Conservation of energy.

 

[Geoffw]

Yes. At the surface, the outgoing long wave must be represent one or the other, escaping long wave or atmospheric heat gain. Conservation of energy.

Thanks for the reply,

Sorry, but to clarify, do you agree with the diagram in vacuo potentials shown as massive opposing fluxes, when the surface total radiative losses are much smaller?

 

[Buzz Bloom]

I think that is miss leading. Even if the atmosphere were argon, the sky would still be blue.

Hi BillyT:

I confess that I am confused by your comment.

I don't understand why you mention argon. As I understand it, there is much much less argon in Earth's atmosphere than nitrogen. Even if, as you say, an argon atmosphere would also appear blue, am I wrong that the blue sky we see are mostly the blue photons from the sun that that been scattered by nitrogen? If so, why do we see blue photons from all directions in the sky?

I also do not understand your discussion of cubes. Are you saying that since 1/5 of the atmosphere is oxygen, that it also scatters blue photons, and 1/5 of the photons we see in the blue sky are scattered by oxygen rather than nitrogen?

Regards,
Buzz

 

[duncan61]

klimatos.I have been seeking the exact information you have provided so well.Regards Duncan

 

[stuartmacg]

While this is likely true for Greenland, it's not at all clear it's true for sea ice.

Brewster's angle (53º) is the angle where about half of light is reflected off the surface of water. This means that above 53º latitude, naively, the albedo of water is over 0.5. (It is far more complicated than that of course -- which is my point.) Since ice and snow's albedo ranges from 0.9 to 0.3, it is not clear water's albedo is lower than ice in the arctic -- even in the summer. (In the winter the albedo is irrelevant because there is effectively no incident sunlight.)

Meanwhile, the arctic area can still "see" the night sky at a 90º angle. Its emissivity remains and the area continues to emit longwave infrared radiation. The limitting factor on this is likely the ∆T⁴between the ground/sea and the night sky. Raising the temperature in the region raises the ∆T and gets that 4^th power emission bonus.

I want to make it clear I am not claiming this melting is a good thing. I'm just claiming it has been poorly studied. The arctic environment is probably the most fragile in the world. Given the large methane deposits in the tundra and oceans (clathrates) which even small temperature rises might release, there is cause for concern.

I can think of a number of things wrong with my model, the most obvious is that water (and arctic ice for that matter) is not flat. Waves will create a chop effect limiting the albedo gain due to the Brewster angle. The Brewster angle will change with the seasonal axial tilt. The atmosphere above the ice will have a large effect since waves incident at a low angle will travel through much more air. These conundrums are just off the top of my head. My point is that this is a complex subject and any positive feedback loop is at best not obvious.

But the idea that the albedo is of great concern in a region getting little sunlight seems oddly immune to logic. Global warming is a big enough problem without adherents practicing bad science and settling for confirming their bias.

I have been asking abut this for a while and not getting any answers. It does seem intuitively that if I were a 0C animal I would not get warmer by taking off my ice coat in the arctic, with -28C Greenland air temp for example.

The low angle summer sun seems unlikely to offset the sunless winter much. 0C water temp must lose heat to the (otherwise << 0C) air, and even a bit directly to space (via the few IR absorption gaps). This heated polar air should export more heat from the earth. If the net effect on the earth of removing ice is heating, I would love to know the details. It seems very far from obvious.

Variable ice, insulating in winter and exposing in summer, might have a heating effect?

 

[haruspex]

if I were a 0C animal I would not get warmer by taking off my ice coat in the arctic, with -28C Greenland air temp for example

I don't understand what point you are making. Please elaborate.
Jeff Rosenbury's argument is that the loss in albedo in going from ice to open water might not be that much. The evidence, though, (https://en.wikipedia.org/wiki/Ice–albedo_feedback#Significance) is that it is significant.

 

[stuartmacg]

Thanks for the link, though it does not directly address the balancing effect of increased heat loss from revealed sea in the cold polar regions.

I am just an uninformed chap who wanted an explanation for what seemed a counter intuitive process folk are talking about. Just curious.

The link does not mention the uncovered sea heat loss effect in describing "albido", but just talks of solar absorption and says all is considered in the models.

Winter only ice cover seems intuitively to be something moving towards a net heating effect, reducing loss in winter and sun bathing in summer - that seems to be called arctic amplification.

Having the previously covered seas heat the polar atmosphere (from <-20C say) all year round will certainly cause more heat export, and in summer get more heat import. It surprises me that the net effect would be warming.

 

[haruspex]

Thanks for the link, though it does not directly address the balancing effect of increased heat loss from revealed sea in the cold polar regions.

I am just an uninformed chap who wanted an explanation for what seemed a counter intuitive process folk are talking about. Just curious.

The link does not mention the uncovered sea heat loss effect in describing "albido", but just talks of solar absorption and says all is considered in the models.

Winter only ice cover seems intuitively to be something moving towards a net heating effect, reducing loss in winter and sun bathing in summer - that seems to be called arctic amplification.

Having the previously covered seas heat the polar atmosphere (from <-20C say) all year round will certainly cause more heat export, and in summer get more heat import. It surprises me that the net effect would be warming.

Ok, now I see your point.
Clearly it is a complex issue requiring detailed modelling, and armchair theorising is unlikely to be reliable. I put my trust in the scientists who have spent careers on it.

 

[stuartmacg]

I don't distrust at all: I would just like to hear something more than silence on the subject, from those who have done the work.

 

[haruspex]

I don't distrust at all: I would just like to hear something more than silence on the subject, from those who have done the work.

Then you will probably need to contact a research establishment.