Man Made Climate Change - Evidence Based Discussion

[Geoffwood]

Devonian, you say,

"The natural GH effect is at least ~33C. Our activities might add 2-4C to that.

But, if you disregard that then, yes, you're going to think it's not a problem."

The Earth's effective black body temperature is indeed 255K. However, the Earth isn't a black body. The Earth's surface emissivity is high at around 0.95 but the atmosphere increases albedo from 0.12 to 0.29.

When we factor these in we arrive at a grey body temperature of 271K. That would be our nearest estimate for the Earth's surface temperature without an atmosphere. So the enhancement of surface temperature due to the current atmosphere irrespective of process is 17K. Not 33K as popularly believed.

However back to Earth's black body temperature of 255K. This is a number we can use to describe the necessary condition whereby the Earth must radiate to space at equilibrium in the long wave the equivalent of the shortwave thermalised (solar flux intercepted post albedo). As what radiates to space is the sea, the land and the atmosphere, using a single number to describe the 'effective mean' of a body of radiators it tells us 'nothing' about the 'highest' or 'lowest' temperatures or there positions. This calculation doesn't 'know' the Earth has a surface therefore doesn't predict the temperature of it. The Earth's effective black body temperature IS 255K. With this atmosphere, now, the Earth behaves like a black body radiator at -18degC!!

On average this temperature (-18degC) is found globally at ~5km above the surface. The thermal relationship between the surface and the atmosphere within the troposphere is the gravitationally driven lapse. This isentropic or reversible adiabatic profile is dT/dh=-g/Cp and averages -6.5K/km.

So, 5km times 6.5K/km (sign reversed as we are descending) gives 32.5K increase at the surface through reduction in gravitational potential energy at the surface. -18 plus 32.5 gives an 'equal kinetic and potential energy' at the surface of 14.5degC

-18degC at 5km is the same total kinetic energy and potential energy as 14.5deg at Okm. No radiative enhancement detectable in surface temperatures! The atmosphere is not in radiative balance.

[Midlands Ice Age]

I've certainly spent far to much time reading the likes of WUWT, that 'Goddard' fellow and the rest....

 

As to the 'ppm' bit, I just thought it was interesting to ponder if expressing a concentration by 'ppm' as opposed to 'ppt' gives a different impression.

 

Dev....

 

Don't post much here, but the figures you are trying to 'soften'  (400ppm) equate to 4 parts in 10,000 or if you prefer it to 1 part in every 2500. That is small now matter how it is dressed up!!!!!   (Or to use other terms more generally used  in every day use and possibly to help to understand its 1 millimeter in every 2.5 meters. Think of the size of a human plus some more compared to a milimeter.

 

Don't know if it helps.....

 

MIA  

[knocker]

A touch of smoke and mirrors here.

 

The infrared emission from the surface of the earth is slightly less than than that from a black body at the same temperature and, accordingly, Stefan's equation is modified by an emissivity coefficient, which is generally between o.90 and o.95.

 

The net warming contribution of the natural (non-anthropogenic) greenhouse gases to the mean 'effective' planetary temperature of 255K (corresponding to the emitted infrared radiation) is approximately 33K; of this, water vapour accounts for 21K, carbon dioxide 7K, ozone 2K, and other trace gases about 3K.. Ergo the present surface temp. is 288K.

[stewfox]

Because i have a different viewpoint I am now a dragon who needs to get reality and must try harder and learn that my views are incorrect. Don't you just love these discussions!!!!

 

Unfortunately that's why these threads get closed unwarranted criticisms.

 

There has been no global warming since 1998 and until we see a sustained temperature rises well in excess of the figures for 1998 the fast majority of people will have no interest (unless they have hidden agenda) in the circular arguments.

 

Its like debating who will win a football match 5 minutes into the game, at the end of the day you just have to wait.

Edited August 20, 2014 by stewfox

[Geoffwood]

Knocker,

"A touch of smoke and mirrors here."

Obviously, without redirect, this describes your own post.

[Geoffwood]

Knocker,

"The net warming contribution of the natural (non-anthropogenic) greenhouse gases to the mean 'effective' planetary temperature of 255K (corresponding to the emitted infrared radiation) is approximately 33K; of this, water vapour accounts for 21K, carbon dioxide 7K, ozone 2K, and other trace gases about 3K.. Ergo the present surface temp. is 288K."

Would you please give details of these calculations.

[Geoffwood]

Knocker,

A few days ago you quoted three lapse rates with initials preceding. One of the letters in each was the letter 'A', what does that stand for and what does that word mean?

Are you purposefully detracting from the rates you 'understand' and quoted?

[knocker]

Knocker,"The net warming contribution of the natural (non-anthropogenic) greenhouse gases to the mean 'effective' planetary temperature of 255K (corresponding to the emitted infrared radiation) is approximately 33K; of this, water vapour accounts for 21K, carbon dioxide 7K, ozone 2K, and other trace gases about 3K.. Ergo the present surface temp. is 288K."Would you please give details of these calculations.

 

No as I haven't got them to hand but are you disputing them as they are the accepted explanation?

Knocker,A few days ago you quoted three lapse rates with initials preceding. One of the letters in each was the letter 'A', what does that stand for and what does that word mean?Are you purposefully detracting from the rates you 'understand' and quoted?

 

No because the lapse has nothing to do with it.

 

Adiabatic which I assume you know as it's common in meteorology. The rate at which atmospheric temperature decreases with increasing altitude in conditions of thermal equilibrium. In use a great deal with thermodynamic diagrams. But this way off the subject.

Edited August 20, 2014 by knocker

[Geoffwood]

Knocker,

No it doesn't mean that. It means no energy leaves.

Where Q= energy

For adiabatic dQ or rate of change is zero.

For an isentropic or reversible adiabatic the net radiative flux is near zero or it doesn't radiate at all. If we compress or reduce the pressure of a gas we have Boyle's law providing we allow time for the system to lose or gain energy to or from its surroundings. Adiabatic refers to an inability to do so. The net of incoming and outgoing fluxes add to zero. Ergo the bulk of tropospheric dynamics allow energy to not be altered relative to the total tropospheric profile which is conservation based upon insignificant loss.

Prediction. You will contend this. Then I will quote you from the IPCC Energy Balance.

[Crepuscular Ray]

Knocker,A few days ago you quoted three lapse rates with initials preceding. One of the letters in each was the letter 'A', what does that stand for and what does that word mean?Are you purposefully detracting from the rates you 'understand' and quoted?

Dear oh dear. I assume you mean DALR, SALR and ELR (dry adiabatic lapse rate, saturated adiabatic lapse rate and environmental lapse rate). Basic A-level geography material and I really don't see why you're bringing it into the AGW argument. As far as I'm aware most knowledgable sceptics don't have a problem with it.

 

Did anything Knocker said imply that he thought that it didn't mean that no energy leaves? Pardon me if I'm wrong. You could prove my suspicion that you're a troll wrong by posting coherently about why you think Knocker's explanation of the word adiabtic disproves AGW rather than is just a red herring that you're using to attack him. 

Edited August 20, 2014 by Crepuscular Ray

[knocker]

Knocker,

No it doesn't mean that. It means no energy leaves.

Where Q= energy

For adiabatic dQ or rate of change is zero.

For an isentropic or reversible adiabatic the net radiative flux is near zero or it doesn't radiate at all. If we compress or reduce the pressure of a gas we have Boyle's law providing we allow time for the system to lose or gain energy to or from its surroundings. Adiabatic refers to an inability to do so. The net of incoming and outgoing fluxes add to zero. Ergo the bulk of tropospheric dynamics allow energy to not be altered relative to the total tropospheric profile which is conservation based upon insignificant loss.

Prediction. You will contend this. Then I will quote you from the IPCC Energy Balance.

 

If you want the definition worded a different way

 

The displacement of an air parcel to an environment of lower pressure (without heat exchange with surrounding air) causes an increase in its volume and a consequent lowering of its temperature. A volume increase involves work and the consumption of energy, thus reducing the heat available per unit volume and hence the temperature. Such a temperature change, involving no subtraction or addition of heat, is termed adiabatic. Vertical displacements of air are obviously a major cause of adiabatic temperature changes.

 

None of this has anything to do with CO₂ and the greenhouse effect so no I won't be contending anything as this has rapidly become pointless.

Edited August 20, 2014 by knocker

[Geoffwood]

Crepuscular Ray,

Sounds like I struck a chord there. Got a vein pumping.

I asked what the word meant. The answer was wrongI gave a level headed answer. And isn't knocker capable of responding all by himself? Are you his hand-holder?

[Crepuscular Ray]

See Knocker's more recent post, clarifying his answer (which wasn't in itself incorrect, but might have needed rewording for the non-expert). Your response doesn't answer why you're trying to bring adiabtic lapse rates into a discussion on AGW and could be said to prove my point that you appear to be trolling.

Edited August 20, 2014 by Crepuscular Ray

[Geoffwood]

Knocker and Crepuscular Ray please explain how, despite massive changes in density and optical path length at long wave radiation wavelengths how the lower troposphere isn't any warmer than bringing an air parcel down from the upper troposphere. Where is the greenhouse effect measurable and demonstrable?

[Crepuscular Ray]

Where is the greenhouse effect measurable and demonstrable?

The entire planetary surface. if it weren't for the greenhouse effect, none of us would exist.

 

Your theories might be better in one of the general weather theory threads as they appear to be a contradiction of the whole of mainstream meteorology rather than just AGW.

Edited August 20, 2014 by Crepuscular Ray

[Geoffwood]

Ok we'll do this anyway.

According to Trenberth's energy budget as used by the IPCC.

From the incoming solar energy thermalised, which is (1-albedo), some 23% of solar radiation thermalised is absorbed by the atmosphere. So of the 71%(1-albedo) 23% or 0.32 of the thermal budget is absorbed by the atmosphere.

From the same budget of the net outgoing flux of 17%, 5% is absorbed by the atmosphere and 12% transmitted. 29% of net energy lost by the surface to space is absorbed by the atmosphere.

So 32% of the radiative heating of the surface and 29% of the radiative losses to space are absorbed by the atmosphere. Aren't these very similar proportions? Does it sound like energy can get in but can't get out due to wavelength dependent properties?

[Crepuscular Ray]

That's the greenhouse effect as applied in general, but how does it disprove accelerated anthropogenic global warming?

 

Bored now.

Edited August 20, 2014 by Crepuscular Ray

[Geoffwood]

Crepuscular Ray,

Care to show something other than chaff.

The lapse rate can be derived and contains vibrational modes as part of Cp. Please SPECIFY THE DETAILS OF MY ERRORS.

[Geoffwood]

Crepuscular Ray,

At last you got to the point. There is no 'accelerated anthropological warming' atmospheres don't work that way.

[knocker]

Okay let's start with this

 

The lapse rate

And then move on to this in particular.

 

Learning from a simple model

 

 

A lot of what gets discussed here in relation to the greenhouse effect is relatively simple, and yet can be confusing to the lay reader. A useful way of demonstrating that simplicity is to use a stripped down mathematical model that is complex enough to include some interesting physics, but simple enough so that you can just write down the answer. This is the staple of most textbooks on the subject, but there are questions that arise in discussions here that don’t ever get addressed in most textbooks. Yet simple models can be useful there too. - See more at: http://www.realclimate.org/index.php/archives/2007/04/learning-from-a-simple-model/#sthash.NwZ3KJIL.dpuf

 

Edited August 20, 2014 by knocker

[Geoffwood]

Knocker,

So now you understand it. Find fault with my argument. It's easy, just point to the parts that are incorrect!

[Devonian]

Devonian, you say,"The natural GH effect is at least ~33C. Our activities might add 2-4C to that.But, if you disregard that then, yes, you're going to think it's not a problem."The Earth's effective black body temperature is indeed 255K. However, the Earth isn't a black body. The Earth's surface emissivity is high at around 0.95 but the atmosphere increases albedo from 0.12 to 0.29.When we factor these in we arrive at a grey body temperature of 271K. That would be our nearest estimate for the Earth's surface temperature without an atmosphere. So the enhancement of surface temperature due to the current atmosphere irrespective of process is 17K. Not 33K as popularly believed.

Humm, you include atmospheric albedo in your calculation and then say your calculation is for the surface without an atmosphere - neat.

However back to Earth's black body temperature of 255K. This is a number we can use to describe the necessary condition whereby the Earth must radiate to space at equilibrium in the long wave the equivalent of the shortwave thermalised (solar flux intercepted post albedo). As what radiates to space is the sea, the land and the atmosphere, using a single number to describe the 'effective mean' of a body of radiators it tells us 'nothing' about the 'highest' or 'lowest' temperatures or there positions. This calculation doesn't 'know' the Earth has a surface therefore doesn't predict the temperature of it. The Earth's effective black body temperature IS 255K. With this atmosphere, now, the Earth behaves like a black body radiator at -18degC!!On average this temperature (-18degC) is found globally at ~5km above the surface. The thermal relationship between the surface and the atmosphere within the troposphere is the gravitationally driven lapse. This isentropic or reversible adiabatic profile is dT/dh=-g/Cp and averages -6.5K/km.So, 5km times 6.5K/km (sign reversed as we are descending) gives 32.5K increase at the surface through reduction in gravitational potential energy at the surface. -18 plus 32.5 gives an 'equal kinetic and potential energy' at the surface of 14.5degC-18degC at 5km is the same total kinetic energy and potential energy as 14.5deg at Okm. No radiative enhancement detectable in surface temperatures! The atmosphere is not in radiative balance.

Hell of a lot of books, atmospheric science courses and scientists out there that are wrong then. You must be the new Galilleo! Edited August 20, 2014 by Devonian

[Devonian]

Dev....

 

Don't post much here, but the figures you are trying to 'soften'  (400ppm) equate to 4 parts in 10,000 or if you prefer it to 1 part in every 2500. That is small now matter how it is dressed up!!!!!   (Or to use other terms more generally used  in every day use and possibly to help to understand its 1 millimeter in every 2.5 meters. Think of the size of a human plus some more compared to a milimeter.

 

Don't know if it helps.....

 

MIA

Cheers, I just thought it was an interesting way of looking at it - but, if it pleases you, it was indeed all part of a conspiracy to mislead by people like me Edited August 20, 2014 by Devonian

[Geoffwood]

Devonian,

No I do not use an atmospheric albedo. The albedo is that of the moon. It's the same rock.

Devonian, feel free to question any step. It's a sensibly arrived at calculation

We can derive the lapse from kinetic theory if you choose.

[Devonian]

Unfortunately that's why these threads get closed unwarranted criticisms. There has been no global warming since 1998 and until we see a sustained temperature rises well in excess of the figures for 1998 the fast majority of people will have no interest (unless they have hidden agenda) in the circular arguments. Its like debating who will win a football match 5 minutes into the game, at the end of the day you just have to wait.

Stew why do you pick 1998 to start your trend from? Why, for example, not 1994 (20 years)?Well lets extend the football analogy. A football club has the following finishing position in the league:18, 17, 18, 16, 16, 15, 16, 14, 8, 15, 15, 14, 12, 11, 12, 10, 8. Using the same logic as your comment above wrt 1998, we could say they handn't improved for 8 years but that would clearly be to focus on the one exceptional year rather than the longterm trend towards a better league finish... Edited August 20, 2014 by Devonian