Science a GoGo's Home Page Forums General Discussion Climate Change Forum Human Influence on Climate

It is not fewer collisions, it is the same number of collisions with only a miniscule increase in a trace gas. Changing the concentration by 0.0002% is not going to have a detectable influence on pressure P=V/T.



I never said that would be the case. I just observed that the atmosphere, that is prodominantly nitrogen, oxygen, argon, and water vapour with traces of other gases like carbon dioxide, has not been letting much heat out. CO2 does not have the correct wavelengths to close most of the current window. Increasing its concentration will not retain much more energy. Looking at Canuck's graph, only the right hand edge of the blue section will be affected. Looking at the "area graph" there has to be a doubling of CO2 for a small increase and only half of it matters to warming (the left edge).

The original equation comes from Arrhenius (1896). A non-skeptic's site?

How about Wikipedia. It is usually good for the basics like the pvt

formula:


Arrhenius linked temperature and CO2 concentration in a logarithmic relationship and that basic relationship still held until

1998?

If wikipedia is not good enough, then how about the IPCC?

CO2 ΔF = αln(C/C0) α = 5.35

Further you suggest that "[a]bsorption of IR quanta is a quantum process..." You also implied

yesterday that Newtonian physics

is appropriate when looking at the energy transfer via collisions. The reason quantum mechanics was created as a theory was

because molecules on that scale do not conform to newtonian physics.

Finally, a National Academy of Sciences site suggests that W*m-2 can

be converted to temperature when it reads, "... 4 W/m2 (the forcing for a doubled atmospheric CO2) would be an increase of

about 1.2°C (about 2.2°F)."

Oh, "natural logs" ...are something I used to have a neat insight about, but alas I'd have to study that again.
This "Myhre expression" is not the equation that I'm challenging, but it is a good response about the relationship between temperature and concentration. I can't believe I never read that link before; thanks.

Natural logarithms don't decay as steeply as do the base 10 logs; but...
Yes, still a good point.
So you're not disputing this well-established climate science (although I realize there are refinements happening occasionally). I thought this logarithmic temperature thing was a new "discovery."

Canuck first brought up this logarithmic/extinction subject as relating to the temperature change; and I still maintain that it is "junk science" based on a copied and altered graph circulating only in the blogosphere.
The steep logarithmic Extinction Coeff. is not the parameter that correlates with, or affects temperature.
I'm going to continue to rely on the long established graphs relating GHG concentration and temperature, until I see some scientific vetting and acceptance of any new interpretations of these parameters.

Or was I mistaken? Wasn't this about some new logarithmic way of calculating CO2's warming effect?
.
.
.
...and yes, those last three posts of mine are not up to the standards displayed on the rest of this thread. As you noticed, the replies didn't even focus on the points you made.
Posting stuff written "in anticipation" is not a good strategy.

The P=T/V comment wasn't meant to say anything about greenhouse warming; it was only meant to suggest the linear character of gas behaviours in general.
...and I knew when I wrote that about the Newtonian stuff, I was opening myself up to some obvious challenges;
but isn't Boltzman-type "statistical mechanics" about the same as Newtonian mechanics?

I recently reread the first page of this thread and found two mistakes I'd made (such as saying shorter wavelength when I meant longer [groan]), but that should be an obvious mistake. I still think this thread is a good (mostly accurate) view of the P.Chem. involved with this process. At least first year students, after reading this thread, would know why they were learning the stuff Physical Chemists teach.

~Cheers

this thread is going nowhere.

Samwise doesn't believe CO2 increases doesn't have a logarithmic effect of temperature (excluding water vapour feedbacks)?

Fine - argue with the following "denialist" site

http://www.britannica.com/eb/article-274825/global-warming

Or perhaps you'd rather argue with Arrhenius????

http://www.globalwarmingart.com/images/1/18/Arrhenius.pdf


Fact of the matter is, each doubling of CO2 concentrations yields 4 Wm2. 250 to 500 gives us an additional 4 Wm2. 500 to 1000 gives us the same 4 Wm2. 1000 to 2000 gives us yet another 4 Wm2. In my book, that's a logarithmic relationship.

I'd be looking at your own posts, before accusing others of spreading junk science, samwise.

Moving on...

Using the simplified IPCC ΔF = 5.35*ln(C/C0) formula and knowing that 1 Joule is equivalent to 1 Watt*second let's now figure out how accurate it is.

ΔF = 5.35*ln(380/280) = 1.633792 W/m²

That is 1.633792 extra Joules per second per square meter that are being added since the CO2 concentration was 280 ppm back around 1750.

Given:

- Earth's surface area is about 510,072,000 km² = 5.1 x 10^14 m²
- Using 365.25 days per year (standardized for leap years), there are 31557600 seconds per year

Joules added each year = 1.633792 * 5.1 x 10^14 * 31557600 = 26294862753792000000000 J = 2.629486x10^22 J

In other words, there is 2.629x10^22 Joules per year of extra energy being trapped by CO2 if the formula is correct.

Now, how much energy is needed to increase the atmosphere by 1 °C?

Given:
- Total atmospheric mass is 5.1480×10^18 kg
- Specific heat capacity of air (cp) is 1.0035 kJ/kg*K = 1003.5 J/kg*K

Therefore, heat required to raise temperature of atmosphere 1 °C = 5.137 x 10^18 x 1003.5 = 5.1549795 x 10^21 J.

Dividing J added each year by the J needed to raise the temperature of atmosphere 1 °C we get the number of degrees for the Joules of excess energy per year:

2.629486x10^22 / 5.1549795 x 10^21 = 5.1 °C

Our temperature is not rising that much each year. It is not even rising 0.5 °C each decade. If the natural log relationship is correct, then that means their 5.35 constant is off by more than a factor of 100.

Paul

About your comments on rain and humidity, the NOAA have a graph that shows how specific humidity from the surface to about 8 miles up has been on the decline globally. If that link is to busy, Watts has a copy on his blog.

I'm no math whiz, and I may have some things wrong; but not the stuff I cite....
Isn't there a big difference between geometric progressions and logarithmic progressions?
===

Real quickly ("Lunchtime Little Theatre")... Those look like good links, but I haven't looked yet.

I don't think anything I've said will conflict with those sources you've cited.
My objection is to that bar graph (yellow w/ blue bars, wasn't it?), and the conclusions made about CO2 having no effect on warming, based on that graph. Has anyone, even climatAudit, found the source of that graph?
Any citation for it?

Sorry to eat and run; I'll look at this more tonight....

~Thanks.

In my 26570 comment above, I recreated a graph similar to the yellow bar graph using a formula Motl described as popular. Here is another one using the IPCC ΔF = 5.35*ln(C/C0) formula:



Note, I used 1 as the initial CO2 concentration since using 0 would give a divide by zero error. The spreadsheet formula is =5.35*LN(V65/V64)

Hey, I just noticed that a lot of the mechanisms of heating that I've been talking about are also explained similarly on that American Institute of Physics site that I cited in my second post to this thread.

http://www.scienceagogo.com/forum/ubbthreads.php?ubb=showflat&Number=26109#Post26109
I should have looked at that 'aip' site earlier, and just quoted stuff from there rather than composing an explanation out of what I recalled from my college days.

http://www.aip.org/history/climate/simple.htm#L_0141
"It appeared that there was already enough CO2 in the air so that its effect on infrared radiation was "saturated" — meaning that all the radiation that the gas could block was already being absorbed, so that adding more gas could make little difference. Moreover, water vapor also absorbed heat rays, and water was enormously more abundant in the atmosphere than CO2. How could adding CO2 affect radiation in parts of the spectrum that H2O (not to mention the CO2 itself) already entirely blocked? These studies with the crude techniques of the early 20th century were inaccurate. Modern data show that even in the parts of the infrared spectrum where water vapor and CO2 are effective, only a fraction of the heat radiation emitted from the surface of the Earth is blocked before it escapes into space. And that is beside the point anyway. The greenhouse process works regardless of whether the passage of radiation is saturated in lower layers. As explained above, the energy received at the Earth’s surface must eventually work its way back up to the higher layers where radiation does slip out easily. Adding some greenhouse gas to those high, thin layers must warm the planet no matter what happens lower down."

.
.
.
Looking back, some more, I see your were always talking natural logs. What about the mikechurch (yellow) graph?
What about your formula from:
http://motls.blogspot.com/2008/01/why-is-greenhouse-effect-logarithmic.html
[-a deadly site- you'll be snow-blind after reading one paragraph -from the actual 'black' page]
"With the assumptions listed above, and they are kind of - although not perfectly - satisfied for the doubling from 280 to 560 ppm of CO2 as one can check (the temperature change comparable to 1 °C is much smaller than the 300K absolute temperature, the percentages change from 92:8 to 95:5 or something like that is relatively small), the Arrhenius' law is a law. It is all about the Maxwell-Boltzmann distribution, the lapse rate, and the black body law. A geometric/exponential increase of the concentration moves the physical phenomena linearly in altitude and makes standardized linear contributions to various terms."
This is gibberish, isn't it?

Ow, my eyes! I had to look at that site again to get this.
"Phenomenologically, the linear increase for small C and the logarithmic law for the large values of C is often interpolated by a function that is also quadratic in the middle but it is just one of possible conventions for curve-fitting. Another popular function is
Temperature = Temperature0 + ln(1 + 1.2 x + 0.005 x2 + 0.0000014 x3)
where "x" is the CO2 concentration in ppmv. This formula works pretty well up to 1,000 ppmv.

However, the asymptotic logarithmic behavior for large C is more than a convention. It can be derived as a result of an idealized calculation that is relatively realistic - a kind of calculation that theoretical physicists, especially condensed-matter physicists, should like. One reason for the logarithm could be found if we were looking how new spectral lines and their "wings" become relevant for the absorption. The old lines eventually get saturated but the total greenhouse warming never quite stops because new spectral lines emerge: it just slows down...."

Holy Crap! Talk about gibberish....

And that formula is the one I said somebody had switched Absorption and Temperature (and relabeled the graph).
Uncitable concoction, I still maintain.

Now, your chart/graph John, (thanks for all your time making that work, btw) as you say is similar because it has a ln factor. Especially if you plot absolute change in concentration instead of the change ratio. You've simply repeated the Motl (now I know who that is) graph by plotting the preceding concentration subtracted from the successive concentration, haven't you?
Or... why doesn't 2 ppm give almost infinite Forcing???

IMHO
Your x axis should go from zero to five(ish), to represent the Concentration ratio of C/Co (i.e. 560/280 would be 2 on the x axis, or 350/280 would be 1.25), and could then be plotted against the delta F (change in Forcing from the initial forcing of Co).
This way also, if you looked at 200ppm/280ppm, the natural log would be negative (showing the lowering in forcing relative to the initial forcing of Co at 280ppm.

I think that is what the ΔF = α ln(C/C0) equation is trying to show.
Does that make sense?

Thanks again,
~Later

It is negative because you have the initial over the new reading. It should be 280/200. don't worry about the really small numbers. The formula does not work well near zero. Similarly, Motl wrote that his popular formula only works well up to around 1000 ppm.

What I am trying to show is that the 5.35 constant used in the IPCC ensemble of models is way too high. Any model that uses this simplified version or any other (third or fourth order) version that produces similar results will yeild results that are too high. The IPCC estimate of human influence on climate change is way too high.

Can you find any citation for "his popular formula?"
===

John,
re: the ΔF = α ln(C/Co) equation.

I'd hoped you might update your last post, but....

I'm sure you'll realize that 200/280 is not "upside down" as you suggested, but is just an example of a final CO2 concentration lower than the "standard" initial concentration of 280ppm [Co] used for the reference point (based on the pre-industrial level).
So, if somehow CO2 levels were to be brought down to 200, the graph shows that the forcing would be negative (relative to the forcing at 280).
For this equation, F is negative for the natural log of fractions (less than one); 200/280 = 0.7143....

I only included the (far-fetched) example of 200/280, to show how the equation would graph if the x axis measured C/Co, instead of the way you set it up.

This whole claim about the logarithmic effect of CO2, thus meaning that CO2 didn't matter, came about out of Richards comments:
... on the 4th post of this thread.

I have agreed that there's plenty of room for debate over the value of alpha; the how, where, and when of CO2's effects.
However, four pages later, I hope it's persuasive that whatever adjustments might need to be made to alpha, the adjustments have nothing to do with this recently suggested logarithmic effect of CO2. The only references to this newly incorporated effect comes from the blogosphere, a few private websites, and some uncitable graphs; and are based on obsolete information or unsupportable interpretations of a gas's physical parameters.

Adjustments to alpha would depend on the positive and negative feedbacks related to humidity, clouds, and various other atmospheric dynamics.
Why is it that you think the IPCC estimate for alpha is too high?
Cirrus clouds perhaps?

~Later,
...

Of course if the concentration goes down then the forcing would be negative. If you want to make some other graph then go ahead. I was simply showing how the ln graphs were made. They are all similar.

The IPCC estimate for alpha is too high because they are overestimating the effect of CO2 on temperature. They had no other idea of what could be causing global warming, so they subbed in CO2 and blamed us. Their models have falsified. They got it wrong. We are not the cause.

Sorry to leave this hanging for so long; but at least that logarithmic stuff seems fairly well-settled.

About the estimates of alpha.... I think they are aware of other forcers of the climate such as other GHG's, soot, clouds, land-use changes, etc., (but not all forcers, nor the magnitude of known forcers).

What!!?

It's not as if the IPCC just made up that CO2 idea recently.
Throughout this thread we've talked about the original theoretical work done on CO2 as a greenhouse gas back in the 19th century.

ummm, yea....

Just look at the models' projections for the Arctic. They're 20-30 years "off" in their predictions of when the polar cap would melt. Talk about falsification!

http://www.columbia.edu/~jeh1/2008/TwentyYearsLater_20080623.pdf
Global Warming Twenty Years Later: Tipping Points Near
...by James Hansen
"Such phenomena, including the instability of Arctic sea ice and the great ice sheets at today’s carbon dioxide amount, show that we have already gone too far. We must draw down atmospheric carbon dioxide to preserve the planet we know. A level of no more than 350 ppm is still feasible, with the help of reforestation and improved agricultural practices, but just barely – time is running out."

Hey! Good going Jim! Thanks for mentioning that land-use and sequestration stuff and not focusing just on emissions!

http://www.nsidc.org/arcticseaicenews/
June 3, 2008
Arctic sea ice still on track for extreme melt
"Arctic sea ice extent has declined through the month of May as summer approaches. Daily ice extents in May continued to be below the long-term average and approached the low levels seen at this time last year. As discussed in our last posting, the spring ice cover is thin. One sign of thin and fairly weak ice is the formation of several polynyas in the ice pack."
"Inuit report that sea ice is starting to break up near Baffin Bay much earlier than normal this year. They have observed wide cracks in the ice already forming, according to NSIDC scientist Shari Gearheard, who lives and works in the Baffin Island hamlet of Clyde River."

I wonder if the Inuit are needing new words to describe the snows these days.
===

http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/001363update_on_falsificat.html
Update on Falsification of Climate Predictions March 15, 2008; Posted to Author:
Roger Pielke Jr.

"For what it’s worth: I believe AGW is real, based on physical arguments and longer term trends, I suspect we will discover that GCM’s are currently unable to predict shifts in the PDO. The result is the uncertainty intervals on IPCC projections for the short term trend were much too small."
"None of this discussion means that the basic conclusion that greenhouse gases affect the climate system is wrong, or that action to mitigate emissions do not make sense. What it does mean is that we should be concerned about the overselling of climate predictions and the corresponding risks to public credibility and advocacy built upon these predictions."

Even Roger believes "AGW is real."
Roger is saying that "the basic conclusion that greenhouse gases affect the climate" is correct.

His main concern is that "overselling ...predictions" will risk the credibility of science in the public's eye.


It sounds as if Roger Pielke Jr. is worried someone will see that the models are not perfect; and (despite that being normal in science) that someone will then make the illogical jump to a conclusion like "We are not the cause."

~

And how do you know what and when historic CO2 levels were?

Easy - the answer is "we don't"

My point is that CO2 is not the cause; therefore we are not the cause. Do we contribute? Maybe a little. That does not change the fact that the IPCC's temperature graphs have falsified for their high CO2 emission scenarios.

That bit about the arctic is funny though. Are you using a single year to justify your argument?!? It is as though you never read that NASA blamed the 2007 arctic ice melt on wind and the PDO. ( http://wattsupwiththat.wordpress.com/2007/10/03/nh-sea-ice-loss-its-the-wind-says-nasa/ )

That June 3rd article seems to have been a bit premature. As of the end of June, the Northwest Passage is still impassable. ( http://wattsupwiththat.wordpress.com/2008/07/02/northwest-passage-still-impassable/ ) While the ice extent may be less than the 20 year norm, we are still no where near where we were last year.

That whole ocean oscillation concept has allowed us to warm and cool. That is the primary driver, but what is the background warming that could be from CO2? The background warming is what matters. Looking at the HadCRUT data, the world warmed for about 30 years (1855-1885), then cooled for about 30 years (1885-1915) then warmed for about 30 years (1915-1945), then cooled for about 30 years (1945-1975), then warmed for about 30 years (1975-2005). It is no longer warming. The 1945-1975 cooling period is just of special mention since the CO2 levels started to skyrocket around 1945. In light of these oscillations within the temperature record, suggesting that all of the 1980's and 1990's warming is from CO2 does not make sense. That is the subbing part. You are correct that subbing is not correct, but they had nothing else, so they put it on a pedastal and called CO2 the primary driver. This little thought experiment of mine here does not lay blame and simply looks at what is happening. For now, I am ignoring the why.

Let's look at the background trend instead. Taking the mid point of each warming period from the HadCRUT June 18, 2008 data I estimate this:

1870 -0.3
1930 -0.2
1990 0.2

Graphed: http://users.vianet.ca/paulak2r/AGW/HadCRUT20080618.JPG
Current data: http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/monthly
(the second column is the global anomoly in Celsius)

This is a very poor sample of only three points, but it is just for discussion due to the short period of direct temperature measurements. The trend seems to have increased from 0.1 C to about 0.4 C every 60 years. If the 0.4 C trend holds, by 2110 we would be about 0.8C warmer by this measure which is much less than the IPCC TAR's lowest case scenario. It would also be near the top end of the AR4 idealised constant composition commitment scenario for which we don't qualify. Of course, this assumes that the trend will continue at the 1930 to 1990 pace.

The wiki page ( http://en.wikipedia.org/wiki/Solar_variation ) says "[t]he level of solar activity during the past 70 years is exceptional — the last period of similar magnitude occurred over 8,000 years ago." I will not quibble over the 70 year value. That wiki page also quotes Sami Solanki saying 60 years. Will that trend continue to be as high? Maybe. Will it decrease? Maybe. I have no idea what the probability of either is. I want to know if it is linked to this trend increase from 0.1C to about 0.4C every 60 years. The reason for the cooling periods is key at this point.

This is just 'back of an envelope' type of calculation. I submit that I am simply reading numbers from a graph while guessing at the mid points and assuming that the mid points are close to the average. My midpoint of 0.8 C in 2110 could easily be 0.4 or 1.2 C. The point is that background warming (climate) is not the +4 C by 2100 catastrophe that the IPCC has as its upper bound for its worst case scenarios where CO2 emissions continue to be high.

The first active-matrix liquid crystal display panel was produced in the United States by T. Peter Brody in 1972. By the 1990s, laptops, digital clocks, calculators, etc. were all using LCD technology and were plentiful. Nitrogen Trifluoride is also used to make integrated circuits. Your two links do not mention anything about concentration. Nor have I yet found the portion of the spectrum that it absorbs. Without knowing these, it is difficult to assess how much influence this chemical has other than possibly damaging our kidneys.

@Canuck RE: "please don't quote any ice core data."

Can you cite a good reason as to why they should not use such data? Don't the samples yield a direct measure of the atmospheric components at the time the ice formed (limited to available ice, of course)? Much like now: To study the very recent composition and change, 50-yr-old still-inflated tires are sampled. Isn't the ice better than silt and tree ring observations which must be interpreted to 'infer' what the levels were?

Granted: Silt {with its pollen an other organics) and tree ring records give a better measure of the *response* of living things to conditions during a given time and some 'radio-isotopes' can be pulled out of there for further clarification.

Two things that probably have not changed in the time-spans that are relevant to any of these different records:
(1) mean atmospheric pressure -- (essentially, it's the partial pressures of individual gasses that are recorded in the ice)
(2) the freezing temp (triple point, actually--very important)of water.
Based on these two points, I *suspect* that the ice-core data is valid.

Welcome Arcturus66,
Nice to know someone is reading this stuff critically.


I've seen the "reasoning" posted here before. I'll see if I can find a link to one of their answers to that question.
===

I was just surfing around about that NF3 question....

Thanks Mike!
Always interesting stuff on your threads.
...fyi....

GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L10817, doi:10.1029/2006GL026210, 2006

Revised IR spectrum, radiative efficiency and global warming potential of nitrogen trifluoride
J. I. Robson and L. K. Gohar, et.al.

Abstract
Nitrogen trifluoride (NF3) is an industrial gas used in the semiconductor industry as a plasma etchant and chamber cleaning gas. NF3 is an alternative to other potent greenhouse gases and its usage has increased markedly over the last decade. In recognition of its increased relevance and to aid planning of future usage we report an updated radiative efficiency and global warming potentials for NF3. Laboratory measurements give an integrated absorption cross section of 7.04 × 10−17 cm2 molecule−1 cm−1 over the spectral region 200–2000 cm−1. The radiative efficiency is calculated to be 0.21 Wm−2 ppbv−1 and the 100 year GWP, relative to carbon dioxide, is 17200. These values are approximately 60% higher than previously published estimates, primarily reflecting the higher infrared absorption cross-sections reported here.
Received 5 March 2006; revised 11 April 2006; accepted 24 April 2006; published 31 May 2006.
...pay site.... ...but....
.
.
"...the intensities of the two main absorption bands measured in the present work are 72% (840–960 cm−1) [~11 microns] and 23% (970–1085 cm−1) [~10 microns {really 9.8microns}]....

...GWPotential values for NF3 were calculated to be 12300, 17200 and 20700 relative to CO2 for time horizons of 20, 100 and 500 years respectively....

... Current global production levels are believed to be about 2300 metric tonnes per year. ...yields an upper limit of the current mixing ratio of 0.10 pptv. Despite the large GWP of NF3, the amount currently in the atmosphere is so small that the contribution of this molecule to overall radiative forcing is very minor (<10&#8722;4 W m&#8722;2).

...However, with an [estimated by Molina et al. (1995)] atmospheric lifetime of 740 years, there is the potential for essentially irreversible accumulation of NF3 in the atmosphere."
===

It looks as if CO2 will still be the main variable keeping us out of another glaciation.
...more about that later....

Arcturus66, the main problem with ice cores is that two cores taken meters apart have been shown to have vastly different data. There are other problems that are being investigated too. I think this may have been a different thread in the past few months here on science a go go.