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What is Global Warming Potential (GWP)?
#1
Hi All,
I posted on facebook a very simple question. "Does SF6 re-emit?"
An "interesting" discussion with Dr. Roy W Spencer ensued.... Please see attached pdf.

Some say SF6 is a "greenhouse gas" that is 23,900 times more powerful than carbon dioxide. The IPCC used to say that in SAR, but in the TAR they changed that figure to 22,800 at the 100 year time interval.
ie,
http://www.ipcc.ch/publications_and_data...table-2-14

BUT, the "strength" of a "greenhouse gas" is NOT a measured physical property.

For example - SF6 absorbs but does not re-emit (because it conducts away the energy so fast), it is described by IPCC as a powerful greenhouse gas.
Oxygen absorbs some frequencies of sunlight (and warms the atmosphere), and also does not re-emit, yet it is not described by IPCC as a greenhouse gas??
ie,
http://scifun.chem.wisc.edu/chemweek/ozone/ozone.html
"Diatomic oxygen absorbs the highest-energy ultraviolet radiation from the sun, namely, all radiation with wavelengths shorter than 240 nm. However, there is a great deal of ultraviolet radiation between 240 nm and 290 nm that is not absorbed by O2 molecules. This radiation is absorbed by ozone." then
"When diatomic oxygen (O2) in the stratosphere absorbs ultraviolet radiation with wavelengths less than 240 nm, it breaks apart into two oxygen atoms." then, "The resulting oxygen atoms combine with O2 molecules to form ozone." and, "This reaction is exothermic, and the net effect of the previous two reactions is the conversion of three molecules of O2 to two molecules of ozone with the simultaneous conversion of light energy to heat." However, "Ozone absorbs ultraviolet radiation with wavelengths as long as 290 nm. This radiation causes the ozone to decompose into O2 molecules and oxygen atoms." The net result being "This, too, is an exothermic reaction. The overall effect of this reaction and the previous reaction is the conversion of light energy into heat. Thus, ozone in the stratosphere prevents highly energetic radiation from reaching the Earth's surface and converts the energy of this radiation to heat."

So, SF6, O3 and O2 absorb greater or lesser parts of the spectrum of sunlight and all warm the atmosphere, but only SF6 and O3 are considered to be a greenhouse gas???? This is because SF6 and O3 can absorb IR that O2 is transparent to. Ozone (O3) does absorb some IR and the IPCC describes Ozone as a powerful, but short lived greenhouse gas. IPCC states O3 is 1,000 times more powerful than CO2, as a greenhouse gas, but over a 20 year time period has a GWP of only a quarter of that of CO2. The justification, or rather physical property is described by Wikipedia as being "a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range." Yet, SF6 conducts so fast in an atmosphere it has nothing left to re-emit...

What people are quoting when they describe the "strength" of a "greenhouse gas" is the CALCULATED "global warming potential" according to the IPCC, of a particular gas.
ie,
http://en.wikipedia.org/wiki/Global-warming_potential
Excerpt -
"From Wikipedia, the free encyclopedia

Global-warming potential (GWP) is a relative measure of how much heat a greenhouse gas traps in the atmosphere. It compares the amount of heat trapped by a certain mass of the gas in question to the amount of heat trapped by a similar mass of carbon dioxide. A GWP is calculated over a specific time interval, commonly 20, 100 or 500 years. GWP is expressed as a factor of carbon dioxide (whose GWP is standardized to 1). For example, the 20 year GWP of methane is 86, which means that if the same mass of methane and carbon dioxide were introduced into the atmosphere, that methane will trap 86 times more heat than the carbon dioxide over the next 20 years.[1]
"

I think it worth noting the notes on the above linked to IPCC page.
Excerpt -
" Notes:

a The CO2 response function used in this report is based on the revised version of the Bern Carbon cycle model used in Chapter 10 of this report (Bern2.5CC; Joos et al. 2001) using a background CO2 concentration value of 378 ppm. The decay of a pulse of CO2 with time t is given by
[Image: Bern_model_2_zpsc6a2b6bb.jpg]
Where a0 = 0.217, a1 = 0.259, a2 = 0.338, a3 = 0.186, τ1 = 172.9 years, τ2 = 18.51 years, and τ3 = 1.186 years.

b The radiative efficiency of CO2 is calculated using the IPCC (1990) simplified expression as revised in the TAR, with an updated background concentration value of 378 ppm and a perturbation of +1 ppm (see Section 2.10.2).

c The perturbation lifetime for methane is 12 years as in the TAR (see also Section 7.4). The GWP for methane includes indirect effects from enhancements of ozone and stratospheric water vapour (see Section 2.10.3.1).

d Shine et al. (2005c), updated by the revised AGWP for CO2. The assumed lifetime of 1,000 years is a lower limit.

e Hurley et al. (2005)

f Robson et al. (2006)
"

Some may remember a thread I posted some time ago,
The Bern model. What is it, and is it important?
and, some may have read about the Ao term within the Bern CC model.
Astonishing new element in climate fraud uncovered?

In short, this is the effect of the Ao term...
[Image: Bern_CC_Pulse_decay_model_Jonathan_Drake...45aabe.jpg]
No wonder then that note d reads -
"updated by the revised AGWP for CO2. The assumed lifetime of 1,000 years is a lower limit."
In other words, if I have understood this correctly, 21.7% of human activity emitted CO2 NEVER leaves the atmosphere...

The above gives rise to several questions...
How does nature determine between human emitted and naturally emitted carbon dioxide?
What are the physical properties that makes a greenhouse (GH) gas a greenhouse gas?
Why are some gases that exhibit the same or very similar physical properties sometimes described as a GH gas and others are said not to be GH gases? ie, SF6 and O2.
How is the GWP value for CO2 calculated by the IPCC?
Has the method and methodology used by the IPCC to calculate the GWP figures now quoted globally been given scientific approval, or received any science institutional scrutiny outside of the IPCC?
How can the GWP for CO2 be "standardized" to the same figure for 20, 100 AND 500 years?
How can the Bern CARBON (dioxide) Cycle model be applied to other gases with totally different cycles and lifetimes in earth's atmosphere?
How can gases with an atmospheric lifetime of under 20 years have GWP figures for 20, 100, and 500 years?

Just WHAT is the IPCC "calculating" when it produces it's GWP figures for all the supposed "greenhouse gases"???


Attached Files
.pdf   SF6_FB_post_and_discussion_with_Dr_Roy_W_Spencer..pdf (Size: 505.52 KB / Downloads: 163)
.pdf   What_is_the_Bern_model_initial_research_Derek_Alker.pdf (Size: 1.76 MB / Downloads: 127)
.pptx   SRES Bern GCM plots TAR Invalidates IPCC modelling - Derek.pptx (Size: 1.4 MB / Downloads: 152)
.pdf   Joos_2013_ACP_journal.pdf (Size: 5.15 MB / Downloads: 118)
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply
#2
Hi All,
It seems to me from the above that the physical property that a greenhouse gas is supposed to have, as Wikipedia so well describes it, is -
""a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range."
In other wards gases that scatter outgoing longwave [thermal] radiation OLR.

Yet, SF6, which is described as a greenhouse gas has been shown by experimental evidence (please see attachment) to conduct so fast in an atmosphere it has nothing left to re-emit??? Therefore, SF6 is not a greenhouse gas, and it does not "trap" the heat / energy of thermal IR it absorbs over any timescale.

Furthermore,
How much of the downwelling longwave [thermal] radiation DLR is actually directly absorbed (within the atmosphere) sunlight re-emitted at a lower frequency? The measured differences between day time and night time DLR are quite considerable.
Not withstanding the fact that,
Supposed atmospheric "back radiation" (ie, DLR) has never been shown to have a warming effect at earth's surface, which would be in contradiction of the 2nd Law of Thermodynamics. ie, heat of itself can not pass from cooler to a hotter.

The notion that a greenhouse gas unphysically "traps" heat over 20, 100, or 500 year intervals is purely a mathematical construct of the GWP figures. It is NOT, and can not be a measurable physical property (It is physically IMPOSSIBLE to trap heat). How could it also be a measurable physical property, if the supposed measurable physical property is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range.???

The two "properties", "it scatters", and "it traps" are contradictory of each other, and therefore are mutually elusive of each other, ie, BOTH can not be true.

Yes, some gases absorb thermal IR, and yes some gases re-emit (scatter) the IR, but others conduct the absorbed thermal IR too.

However, this does not matter a jot until it can be shown that supposed atmospheric "back radiation" is in fact "back radiation" and that "back radiation" heats earth's surface.

"It scatters", "it traps" is all a misnomer and misdirection in the first place, because without a "mechanism" (ie, a warming effect of earth's surface by atmospheric back radiation) there is nothing to be concerned about in the first place ...


Attached Files
.pdf   pcat2006-06_SF6_conducts.pdf (Size: 284.39 KB / Downloads: 121)
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply
#3
Hi All,
I think this will form a winter project for me... Bern -> Ao -> GWP -> Climate change / green "justified" laws, rules, regulations, limitations, restrictions, AND taxes..

First I will have to do the donkey work of reading through the papers describing the history and evolution of what started as the unphysical ghosts of Uli Siegenthaler and became, after his death, the (University of) Bern Carbon Cycle model.

Unfortunately it appears this will not be simple, either in what the model is supposed to physically describe, AND, the mathematics used... I am not at all good at maths, so I imagine a lot of my time will be asking others about maths... In this respect,
can anyone help me with an excel version of the Bern model PLEASE?
I would like to be able to reproduce some of the calculations / plots the IPCC and Joos produced.

Another area I want to look at is when did the definition of the Ao term change? Certainly the effect of the term seems to be completely different in the IPCC's TAR, compared to the SAR. Before TAR I think Ao was used as a term to help describe deep oceanic "slowness" of response, but by TAR it appears to be an atmospheric term! Quite a difference, that as far as I am aware, is not described in TAR. This also begs the question did the definition of any of the other terms in the model change over time? I do not know, but it is something to check / compare, right upto the latest Fifth AR.

The above is the ground work, the back ground donkey work, for the real purpose of the "project". I want to understand, and be able to explain and show how the GWP figures are calculated by the IPCC. I am not aware that anyone can at present. If anyone knows differently, please post.

At present I think this will be broken down into several topics, as follows.
1a) How does the IPCC calculate a 20, 100, and 500 year global warming potential figure for carbon dioxide?
1b) How does the IPCC then "standardise" these three different figures all to the same number of 1?

2a) How does the IPCC calculate a GWP figure for all the supposed "greenhouses gases" it lists as "greenhouse gases"?
2b) How is applying the carbon cycle, via the Bern model and Ao term to ANY "greenhouse gas" except for lifetime in the atmosphere justified?

3) What are the GWP figures being used for? Who is using them? What is being "justified" by the GWP figures?

I have to wonder, because I know there is no greenhouse effect, does that give me a head start on others who might think about investigating the GWP figures?

It will also be rather enjoyable to look at something without having to trip up over all that imaginary black body and Stefan Boltzman unphysical equation bollocks too....

ANY help from anyone on any part of the project, topics, and areas covered will be very gratefully received.

You know in a perverse sort of way I am looking forward to this winter now...
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply
#4
Footnote - How does IPCC calculate / measure atmospheric lifetimes of the various supposed "greenhouse gases"..

For example, methane.
Another IPCC modeling failure – so THAT’s where the atmospheric methane went

Another possibly useful link..
Methane good or bad

And,
Methane mythology - Joel Kauffman

And,
Destruction of greenhouse gases over tropical Atlantic
New research published in the journal, Nature

26th June '08
Excerpts -
"Large amounts of ozone – around 50% more than predicted by the world's state-of-the-art climate models – are being destroyed in the lower atmosphere over the tropical Atlantic Ocean. Published today (26th June '08) in the scientific journal, Nature, this startling discovery was made by a team of scientists from the UK's National Centre for Atmospheric Science and Universities of York and Leeds. It has particular significance because ozone in the lower atmosphere acts as a greenhouse gas and its destruction also leads to the removal of the third most abundant greenhouse gas; methane. "
and,
" Instruments developed at the University of Leeds, and stationed at the Observatory, detected the presence of the chemicals bromine and iodine oxide over the ocean for this region. These chemicals, produced by sea spray and emissions from phytoplankton (microscopic plants in the ocean), attack the ozone, breaking it down. As the ozone is destroyed, a chemical is produced that attacks and destroys the greenhouse gas methane. Up until now it has been impossible to monitor the atmosphere of this remote region over time because of its physical inaccessibility. Including this new chemistry in climate models will provide far more accurate estimates of ozone and methane in the atmosphere and improve future climate predictions."

But not included in Bern, or Ao, or therefore the GWP figures....
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply
#5
It seems I had better remember RF too...
Radiative Forcing of CO2

Although Wiki seems a little more certain, or is that pessimistic?
Radiative forcing - Wikipedia
The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety)
by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken.  

The hobgoblins have to be imaginary so that
"they" can offer their solutions, not THE solutions.
Reply


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