–Then what do you say about the work of Arrhenius?–
He thought CO2 levels caused glacial and interglacial periods.

And CO2 levels do not cause glacial and interglacial periods.

He tried quantify the effects of CO2 adsorbing infrared,
So:
“In this book Arrhenius first describes the “hot-house theory ”of the atmosphere, stating that the Earth’s temperature is about 30 degrees warmer than it would be due to the“ heat-protection action of gases contained in the atmosphere,”a theory based on ideas developed by Fourier, Pouillet, and (especially) Tyndall. His calculations demonstrated that if the atmosphere had no carbon dioxide, the surface temperature of the Earth would fall about 21 degrees Celsius, and that this cooler atmosphere would contain less water vapor, resulting in an additional temperature decrease of approximately 10 degrees Celsius. ”

And that is wrong. And/or current greenhouse effect theory does not agree. Wiki, Greenhouse Effect:
“By their percentage contribution to the greenhouse effect on Earth the four major gases are:
water vapor, 36–70%
carbon dioxide, 9–26%
So first Water vapor has greater effect than CO2.
Second, 9–26% of 33 K is 2.97 to 8.58 K
So highest range is for CO2 is 8.58 C as compared to Arrhenius estimate
of 21 C

Now I think think current greenhouse effect theory is wrong, but in terms gases which absorb IR, water vapor is without doubt stronger.
It’s stronger with one comparing 1 H2O to 1 CO2 and stronger because
there is far more water vapor than CO2 in the atmosphere.
But for the idea that CO2 causes glacier and interglacial period one would need CO2 to be “about 21 degrees Celsius”.
Therefore his need to explain ice ages and their known variation of CO2
to be caused by CO2 lead to this false assumption.

Btw, had Arrhenius conceived of modern fantasy of runaway effects, he would not have had to pick such high value. Or Arrhenius thought a doubling of CO2 would increase global temperature by about 5 C, whereas currently it’s though a doubling of CO2 causes an increase about 1 C [plus a runaway effect, the warming increases water vapor, which increases temperature causing more water, and etc.]
But of course such runaway effects are foolish and have never been observed.
“The equilibrium climate sensitivity (ECS) refers to the equilibrium change in global mean near-surface air temperature that would result from a sustained doubling of the atmospheric (equivalent) carbon dioxide concentration (ΔTx2). As estimated by the IPCC Fifth Assessment Report (AR5) “there is high confidence that ECS is extremely unlikely less than 1°C and medium confidence that the ECS is likely between 1.5°C and 4.5°C and very unlikely greater than 6°C.”

http://en.wikipedia.org/wiki/Climate_sensitivity

Or IPCC thinks it extremely unlikely there is not some amount of feedback
and thinks it’s .5 to 3.5 C and unlikely it’s 5 or higher.

Another thing Arrhenius got wrong is related to the name of the theory- Greenhouse effect. He imagine that window panes prevent IR from leaving the greenhouse and that explained why greenhouses were warm. But this was also wrong.
Rather what mostly cause cars or greenhouses to get warm is inhibiting
convection of gases. So keep open the car window of the car and the air doesn’t get as hot.

Now, actual greenhouse does not do much in terms of warming Earth.
Or cover entire earth with greenhouses and it doesn’t do much to warm Earth. A greenhouse stops convection of air, but the atmosphere itself stops the heat loss from convection. Or if greenhouse didn’t stop the convection of heat then goes into atmosphere and warm it.
So greenhouse stops heat from escaping via convection and so does the atmosphere.
So both a greenhouse and atmosphere does the same thing- it’s just the atmosphere is massive and any greenhouse humans make is dinky.

Now if have different types window panes that block IR, can have slight effect in causing the greenhouse to be warmer- but mainly is about convective. Similarly greenhouse gases could have slight effect in warming Earth- but they are not the main [only thing] that keeps Earth warm.

That’s a good list, Peter. But you forgot:

21 year old women
21 year old Kentucky Bourbon
Dominican cigars

Which reminds me of what the penniless George Best said, when asked what happened to the fortune he made playing football : “I spent most of it on booze, birds, and fast cars. The rest I squandered.”

You could also add what Earl Butz said to your list, but not here.

Yes, That’s good. I laughed at this bit:

cheap energy (as cheap as possible)

It reminded me of a response I got to a question I posted on a web site during the Copenhagen Climate meeting. I asked what the 114 delegates, support staff and media Australia’s Prime Minister kevin Rudd, were doing at the Climate Conference. the answer came back:

Booze, sex and party, party, party

A number of people asking for a derivation of the calculation and question posed to Judith above.

I make no claim for origniality or accuracy and would happily be corrected.

But for due diligence and audit:

dT(anthro) = (TCR/ln2)*ln(Ci/Cf)

This neglects other anthro influences.

dT = change in temperature for a change in CO2
TCR = TCR
Ci=initial CO2
Cf = final CO2

1950 CO2 = 309ppm*
2010 CO2 = 390ppm

*2010 CO2 is from Mauna Loa data – the Keeling curve. 1950 is extrapolated back from the Keeling curve which only starts in 1958, so that number will be slightly wrong.

Lewis and Curry give TCR 1.05 – 1.8 as the 17-83% range; TCR 1.33 is the midpoint

Plug the numbers in and you get:

TCR % of warming attributed to Co2
1.05 49%
1.33 62%
1.80 84%

I’m aware there is an element of circularity in the argument in that the 1950-2010 period is a subset of the data used by Lewis and Curry.

But it makes the point that if you wish to ascribe <50% anthro to 1950-2010, you have to have an unrealistically low TCR, lower even than the low side of the lowest methodology.

Hi Tony,

I get the feeling we’ve been over this before and as enjoyable as that is, I’m not sure it’s getting us anywhere. I know you are sceptical about the raw material. I am too. However, the points you raise can and have been studied quantitatively. If we want to get a better handle on these things via these discussions, then I would really value some kind of quantitative analysis from you to back up your qualitative claims.

The 10,000 observations form 1850 is not “theoretically true”, it’s approximately how many observations there are in HadSST3 for that year. The observations are not everywhere, but there are measurements from each of the ocean basins and from them it is possible to extract an estimate of the global temperature. As I mentioned above, we can test this by reducing modern high-coverage data to typical nineteenth century coverage and seeing what kind an error this introduces into the estimated global temperature. The uncertainty so introduced is around 0.1-0.2 degC. I dare say with a better statistical approach, that number could be lowered. If you think that number ought to be higher, you’ll have to explain why.

Each of the 5-degree grid cells in HadSST3 that contains data contains anywhere from 1 to (in some modern periods) several thousand measurements. These aren’t like measurements from land stations because ships and buoys come in all shapes and sizes. However, differences between ships are allowed for in our uncertainty calculation. Typically the difference in bias between two ships has a 2-sigma (ie approximately 95%) uncertainty range of over two degrees. The difference between two single observations from two different ships measuring at the same location would be larger still. As I said, this is accounted for in our uncertainty calculation.

We don’t need perfect uniformity of data collection to make a reasonable estimate of global temperature from the marine data. It would be nice if we had it, but for long stretches of time, we don’t. There is a certain degree of uniformity though. Observations made by ships for particular countries were generally given standard instructions and, in some cases, standard equipment.

Best regards,

John

VTG,

You didn’t address the issue I asked you about that you are assuming all the increase in CO2 concentration is due to human activities. As I and others pointed out, CO2 concentration increased during previous warming too. This needs to be taken into account. You have not explained how it is taken into account.

U know it makes sense.

Peter,

as I said to you, before, the anthropogenic attriibution of the CO2 rise is unequivocal, and a simple fact. If you doubt it, I’d suggest some simple research first. AR4 had a section specifically on this, I don’t recall AR5.

If you wish to debate that the CO2 rise is anything other than due to human activity, you need to find someone other than me, I’m not interested.

verytallguy, your formula is messed up. This is an example of what your formula would give:

x = (1.33/ln(2)) * ln(309/390)
x = 1.33/.69 * ln(.79)
x = 1.93 * -.24
x = -.45

That’s obviously wrong. I assume the formula you wanted was:

x = TCR * ln(Cf/Ci)) / ln(2)
x = TCR * ln(390/309) / ln(2)
x = TCR * ln(1.26) / .69
x = TCR * .23 / .69
x = TCR * .33

Which would give dT(anthro) values of .35, .44 and .60, fitting the values you give if we take dT(anthro) to be ~.7.

Which isn’t to say I agree with using the formula. I think that calculation is beyond naive, but I also think we ought to be clear on what the formula is.

VTG,

Sorry, if you can’t answer the question in simple language, and simply resort to “trust me, I’m from the Climate Cult, and I know best, peasant” that’s just appeal to belief. Of course you have no idea what happened in the Roman and Medieval Warm Periods.

If you dodge simple questions like this, why should anyone trust anything you say? (especially since your source is RC and un-SkepticalScience).

Here is the big implication if I am thinking straight. If in general natural trends were, all else equal, causing the overwhelming majority of heating and GHG a minority, but some temporary identified factor caused cooling, this strange inummerate way of speaking would allow you to say more than 50% of the observed warming is caused by GHG. It would be equally true (actually more true) to say natural forces caused more than 50% as well (or maybe more than 100%). But if we only say one and not the other our words have served to misinform.

Peter,

– I have not called you a “peasant”, or indeed any other name
– the only references I have suggested for the anthropogenic nature of CO2 are AR4 and AR5
– the only reason I pointed you to RC was to a specific interaction with Gavin Schmidt. If you truly want to understand the issue, listening to Gavin would be well advised, whether or not you agree with him.

To call me a “cultist” because I accept proven science is an interesting approach to learning.

I accept the laws of motion and thermodynamics. Does that make me a cultist?

Neither me, nor anyone else here is under any obligation to you Peter.

if you want to understand the anthropogenic nature of CO2, go do some research, and good luck.

Having handled lots of CO2, I can vouch for the very obvious fact that freezing or injecting into cold water are the only ready ways to contain it for long outside a sealed space. Only ways that I can think of, at least. Water warms and bye-bye CO2. That’s why your deluxe onion soup done with champers won’t fizz. Even a lot of alcohol stays the course of cooking, but that gas has gone in a trice. (I know this is terribly obvious, but so should Holocene climate fluctuations be obvious. So should the utter boring normalcy of the present warming be obvious.)

So you have some general warming (yet again) on a watery planet and consequently a bit more CO2 to add to whatever we belch? Makes sense. (Apologies for the humans belching, the ppm and all that. If it causes any real probs, we’ll use more nukes in future.)

Of course, there’s also the small matter of the actual Earth, and what it spits out. But that actual hot, porous ball called Earth must be a small matter because it is so studiously ignored by so many studious people. (Can’t really blame them, when you consider the access problems.)

I really hope there has been some global warming lately. Just so I know it’s the same planet it’s always been. Sort of a security thing with me. Also, those last coolings were a bit brisk, even the pea-shooter cooling of the ’70s had ‘em squawking. Probably better off out of that, though I prefer the cool m’self. Particularly bad for Africa, and we don’t want to stir up those celebs.

Brandon,

you’re right, the Ci and Cf are the wrong way around. Thank you.

It was deliberately intended to be a naive calculation, just to illustrate a way of thinking of attribution.

Interested if you think there is anything fundamentally wrong with it as an approach.

[…] artiklar som Judith Currie (Climate etc.) tog upp den 16 januari på sitt återkommande bloginslag ”Week in review”. Hon hade bland annat fastnat för en artikel i tidksriften Nature med rubriken […]

verytallguy, you didn’t just mix up the placement of Ci and Cf. You also misplaced the ln(2) part of the equation.

As for what’s fundamentally wrong with the calculation, there are about a hundred different ways the thing is wrong. The three broadest issues which come to mind are it ignores every forcing save that caused by CO2, completely ignores the time domain and is highly dependent upon endpoint selection. I’d normally ignore all that as it’s a crude approach, but you said:

But it makes the point that if you wish to ascribe <50% anthro to 1950-2010, you have to have an unrealistically low TCR, lower even than the low side of the lowest methodology.

Which is only true if one ignores how crude your approach is. Your approach cannot possibly demonstrate what you believe is actually true.

Brandon,

we both have ln2 on the denominator, so I think you’re mistaken on that.

“it ignores every forcing save that caused by CO2″
– yes, which I specifically pointed out

“completely ignores the time domain ”
– it implicitly assumes that forcings are rising during the period in line with the definiton of TCR. Which is approximately correct

“is highly dependent upon endpoint selection”
– in what way is this different to any other methodology looking at attribution over a period of 60 years?

verytallguy, you’re write about the ln(2) part. You placed it in a different spot than I normally see it (as it isn’t tied to the TCR component), but the math still works out the same.

- yes, which I specifically pointed out

Pointing out your approach uses an assumption does nothing to establish that assumption is justified. I don’t see a need to establish the fact you stated an assumption in order to say your methodology relies upon an assumption, but if you want to, okay.

- it implicitly assumes that forcings are rising during the period in line with the definiton of TCR. Which is approximately correct

I’m not sure just what assumption you think you’re using, but simply saying something is “approximately correct” doesn’t automatically mean it is fine. Unless one has a decent estimate of how much an assumption affects the results, the assumption can’t be relied upon.

- in what way is this different to any other methodology looking at attribution over a period of 60 years?

Saying you don’t know how to do something right doesn’t justify doing it wrong. It also doesn’t require other people figure out how to do it right before pointing out you’re doing it wrong. At a minimum, you ought to try multiple endpoints and see how it affects your results.

Again, not the first one to note this on this thread, but as an example, visit ATTP’s parallel parasitic thread where many of the marooned and barnacled subjects are bouncing the attribution question around in a sack of rocks manner: there is no unanimity or clarity. Each of the commenters themselves have their own interpretation of the AR4/AR5 statements and they surprise each other. Some are learning new ways of looking at the attribution statement *now* – which implies they bought the Susan Joy Hassol version (Climate change is now and we’re causing it) hook, line and sinker and believed it blindly.

The IPCC attribution arguments (as opposed a rigorous scientific treatment of the question) operate under several constraints: the need to fit concerns for positive feedbacks, the need to not accidentally produce a very low value for sensitivity, the obligation to accommodate, and at times, exploit such unknowns as aerosols (very useful but also a pain), and so forth. My impression: it’s simply better to forget about the whole thing. Only religious people take up a statement written in a book, freeze it (as though it were something immutable), and study it and pore over it (instead of the concept/question behind it).

In the simplest terms possible:

dT(1951-2010) = [dT(CO2) + dT(other GHGs) – dT(anthro aerosols) – dT(other -ve feedbacks) + dT(+ve feedbacks)]
– [dT(natural aerosols) +/- dT(internal variability) +/-dT(external – solar] variability)

To arrive at an attribution statement for the degree of temp rise due to human GHG emissions with such startling confidence, you MUST know with equal confidence the contributions from all other climate forcings operating over that period.

The crux of the matter here, putting aside all the complex, opaque, circular reasoning employed to justify the scientific credibility of assigning such a confident statement of attribution, is that the IPCC, Gavin Schmidt and others assume they have accurate estimates of the forcing due to natural variability AND that they have accurate estimates of the system feedbacks due to anthro GHG forcing. They don’t. They are working in the dark, but point a torch (flashlight) somewhere and expect us to believe that the small area thus illumined is representative of reality. It isn’t (very high confidence).