Guest Post by Willis Eschenbach
It’s morning here in Reno, and I thought I’d write a bit more about the Kaya Identity and the Beer Identity. My last post about the Kaya Identity was controversial, and I wanted to see if I could clarify my point. On the last thread, a commenter did a good job of laying out the objections to my work:
Sorry but I think you’ve all entirely misunderstood the point of the identity. The Kaya identity is a means of communicating the factors of which CO2 emissions are comprised, in order to explain the physical levers that are available if one wishes to control an economy’s CO2 emissions.
These are analogous to mathematical factors, for e.g. 6 = 3 x 2. This illustrates that 2 and 3 are factors of 6. This doesn’t prove anything mathematically – it’s just an identity. But it is informative nonetheless. It tells you that 6 can be broken down into factors of 2 and 3. In the same way, CO2 emissions can be broken down into factors of population, GDP per population, energy per population, and CO2 emissions per energy.
That is a very clear and succinct description of what the Kaya Identity is supposed to do. The only problem is … it doesn’t do that.
Let me take another shot at explaining why. To start with, the Kaya Identity states:
where “CO2 emissions” are the CO2 emissions of say a given country; “Population” is the population of that country; “GDP” is gross domestic production of the country, which is the total value of all the goods and services produced; and “Energy” is energy consumed by the country.
The Beer Identity, on the other hand, states the following:
Where all of the other variables have the same value as in the Kaya Identity, and “GBP” is gross beer production by the country.
I think that everyone would agree with those two definitions. They would also agree that both of them are clearly true.
Now, as the commenter said above, when we write
6 = 3 x 2
it tells us that six can be broken into factors of three and two. Not only that, but we can say that for example
(6 * 0.9) = 3 x (2 * 0.9)
That is to say, if we change one of the factors by e.g. multiplying it times 0.9, the total also changes by multiplying it by 0.9.
But is that true of the Beer Identity? Suppose we get more efficient at producing beer, so that it only takes 90& of the energy to make the same amount of beer. Will this decrease our CO2 production by 10%, such that
Well … no. It’s obvious that changing our beer production to make it 10% more energy-efficient will NOT reduce CO2 emissions by 10%. In other words, despite it being unquestionably true, we have no guarantee at all that such an identity actually reflects real world conditions. And the reason why it is not true is that it doesn’t include all of the factors that go into the emission of the CO2, it only includes the beer.
Now, I can hear you thinking that, well, it doesn’t work for gross beer production, but it does work for gross domestic production.
And up until yesterday, I was convinced that the Kaya Identity doesn’t work for GDP any more than it works for GBP … but I couldn’t figure out why. Then yesterday, as I was driving along the Lincoln Highway on my holiday with the gorgeous ex-fiancee, I realized the factor that is missing from the Kaya Identity is … me, driving along the Lincoln Highway on my holiday with my gorgeous ex-fiancee.
The problem is … I’m burning energy, and I’m emitting CO2, but I’m not part of the GDP. I’m not producing anything with that energy—no goods, no services, nothing. My CO2 emission is a part of the total, but it is not included in the Kaya Identity anywhere.
So in fact, the Kaya Identity does NOT tell us the “factors of which CO2 emissions are comprised, in order to explain the physical levers that are available if one wishes to control an economy’s CO2 emissions” as the commenter said.
And that to me is the problem with the Kaya Identity. It’s not that it is false. It is that it gives a false sense of security that we’ve included everything, when in fact we haven’t. And because it looks like mathematical truth, we have folks who take it as gospel, and object strongly when it is questioned or laughed at. Steven Mosher thinks I was wrong to laugh at the Kaya Identity, and I do respect his and the other opinions on the matter, his science-fu is strong … but in fact, the Kaya Identity is no more complete than the Beer Identity, which is why I laughed at it.
So that’s my objection. It’s not that the Kaya Identity is false. It can’t be, by definition its true.
It is that it gives the false impression of mathematical certitude, the impression that it represents the real world, the idea that it identifies the “factors of which CO2 emissions are comprised” … but it doesn’t. This false certainty, because people think it’s “mathematically demonstrable”, leads people to not question whether it applies to the real world.
Finally, in closing let me repeat something I said in the comments on the first thread, which likely didn’t get seen because it was somewhere down around the five hundredth comment.
l hear rumblings that people think that Anthony shouldn’t have published this piece of mine, or should disavow it in some fashion. This totally misunderstands both what Watts Up With That (WUWT) does, and Anthony’s position in the game. The strength of WUWT is not that it is always right or that it publishes only the best stuff that’s guaranteed to be valid.
The beauty and value of WUWT that it is the world’s premier location for public peer review of climate science. On a personal level, the public peer review afforded by WUWT is of immense use to me, because my work either gets falsified or not very quickly … or else, as in this case, there’s an interesting ongoing debate. For me, being shown to be wrong is more valuable than being shown to be right. If I’m right, well, I thought so to begin with or I wouldn’t have published it, and it doesn’t change my direction.
But if someone can point out my mistakes, it saves me endless time following blind alleys and wrong paths. And my opinions on the Kaya Identity may indeed be wrong.
There is much value in this public defenestration of some hapless piece of bad science, whether it is mine or someone else’s. It is important to know not only which ideas are wrong, but exactly why they are wrong. When Anthony publishes scientific claims from the edges of the field, generally they are quickly either confirmed or falsified. This is hugely educational for scientists of all kinds, to know how to counter some of the incorrect arguments, as well as giving room for those unusual ideas which tomorrow may be mainstream ideas.
So it is not Anthony’s job to determine whether or not the work of the guest authors will stand the harsh light of public exposure. That’s the job of the peer reviewers, who are you and I and everyone making defensible supported scientific comments. Even if Anthony had a year to analyze and dissect each piece, he couldn’t do that job. There’s no way that one man’s wisdom can substitute for that of the crowd in the free marketplace of scientific ideas. Bear in mind that even with peer review, something like two-thirds of peer-reviewed science is falsified within a year, and Anthony is making judgements, publish or don’t publish, on dozens of papers every week.
So please, dear friends, cut Anthony some slack. He’s just providing the arena wherein in 2014 we practice the blood sport of science, the same sport we’ve had for a few hundred years now, ripping the other guys ideas to bits, also known as trying to scientifically falsify another person’s claims that you think don’t hold water. It is where we can get a good reading on whether the ideas will stand up to detailed hostile examination.
It is not Anthony’s job to decide if mine or any other ideas and expositions and claims will withstand that test of time … and indeed, it is often of value for him to publish things that will not stand the test of time, so that we can understand exactly where they are lacking.
So please don’t fill up the poor man’s email box with outrage simply because you think a post is not scientifically valid enough to be published. Send your emails to the guest author instead, or simply post your objections in a comment on the thread. Anthony is just providing the boxing ring. It is not his job to predict in advance who is going to win the fight. His job is to fill the fight cards with interesting bouts … and given the number of comments on my previous post about the Beer Identity, and the huge popularity of his website, he is doing it very well.
Regards to each and all of you, my best to Mosher and all the folks who have commented, and my great thanks to Anthony for the huge amount of work he does behind the scenes to keep this all going. I’m on the road again, and my highway CO2 emissions are still not included in the Kaya Identity …
w.
As Always: If you disagree with something that someone has said, please have the courtesy to quote their exact words. It avoids much confusion and misunderstanding.
Andrew N @7:06 pm:
“Actually I feel that it is a bona fide equation . . . In other words, if you change any of the variables, Population, GDP intensity, Energy intensity or CO2 intensity then the total CO2 emitted changes.”
I think that’s the right approach.
pwl @8:43pm:
Yes, I do recall seeing several of those kinds of studies a few years ago. Unfortunately, they have now been falsified. 🙂
Daniel G. says:
July 12, 2014 at 2:50 pm
Ah but it is a shell game, the M on the left is not the same M we have on the right is it?
Kaya Identity is analogous, because we have been using symbolic a/b to represent a ratio variable.
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Daniel, the number 1 is a ratio and that a/b is a ratio as you rightfully say. A ratio is just a rational number. But I repeat myself.
In order to find a value for a/b you need to know a and b.
Kaya is a mess because it uses [total CO2 we don’t know what it is before we do the calculation] divided in this case by [total to the last drop energy consumed to produce the GDP] to FIND CO2.
With respect to the M&M identity. One doesn’t count all the M&Ms ahead of time and divide by the total number of packages to figure out how many M&Ms there are in a package, that is M/P. One picks up one (or 2 or 3 but not P) package and count the M&Ms and divide that by one (or however many) package and now you have a ratio with independent information to use in the formula. This is why I say the M on the left is different from the M on the right, the M on the right is an increment of the total M. Now if one did decide to count all the M&Ms and divide by the total number of packages it would be the same ratio, but they’d now just using the M you are looking for to calculate the M you want.
[snip off topic – not going there again -mod]
anna v @8:52pm and
James Gibbons @9:01pm:
The issue is that the equation as written by Willis (and the graphic equation in Wikipedia*) is incorrect.
With the correct equation we could have avoided the great majority of this thread, although the more substantive issue of whether the equation variables in fact capture reality would still be open for discussion.
—–
*I note, however, that the text in Wikipedia (at least a couple of hours ago) does not match up with the graphic equation. The text seems more correct.
Just get pulled over and fined for one of the many imaginary “victimless crimes” and you’ll be part of the GDP – if you pay of course.. 😉
I think it is worth reminding folks that GDP is an *aggregate* measure that typically changes only *gradually*. It is pretty trivial to construct a hypothetical that could make the Kaya identity useless FAPP. For instance, if all the families with one working and one stay at home parent, suddenly forced the working parent to send a cheque for childcare services to the nonworking one, we could have a huge jump in GDP that wouldn’t have any impact on CO2 emissions.
The first point is, though, that these sorts of things may either be insignificant in terms of the total size of the economy and/or move more or less in tandem with other changes in the economy so the equation may still be useful, for instance, in predicting the effect of a recession on CO2 emissions.
And this leads to the second point, which is, is Kaya useful? i don’t know the answer to this question (and I suspect it might not be). Can we, for instance, measure the relevant data surrounding the 2008 recession and come up with a reasonably close estimate of the actual CO2 emitted in 2008? If we can, then all the other objections seem moot to me and if we can’t, there isn’t much benefit to Kaya one way or another.
Cheers, 🙂
My first article in Communications of the ACM had some major issues. Unlike the academic journals in my field of information systems, CACM publishes letters to the editor and I really got hammered. It was a very painful experience for me, but the problems did get adequately exposed.
In contrast, there was a seriously flawed publication by a prominent figure in a top academic journal in my field. A colleague saw it, recognized the problems and submitted a rebuttal paper. Although the reviewers acknowledged the problems, it went through a stalling process of multiple review cycles and then was rejected.
I suspect things work like that in other fields also.
Roger Pielke Jr. has weighed in. He’s one of those scientists who has actually used the Kaya identity correctly. Those who don’t get it are encouraged to read more.
http://rogerpielkejr.blogspot.com/2014/07/common-ground-on-climate.html#comment-form
Rdcii says:
July 12, 2014 at 5:35 pm
(T Co2 Emissions) = (X Population) * (Y GDP / Z Population) … * (A Co2 Emissions / B energy)
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The population can’t be different values in the same equation, X = Z. Goes for the CO2 also, CO2 emissions has to be the same on both sides of the equation (T = A).
I don’t blame you wanting to avoid that. It is part of the bigger picture, though old news. You guys do a good job.
” The Kaya identity (CO2_{emissions} = Population * \frac{GDP}{Population} * \frac{Energy}{GDP} * \frac{CO2_{emissions}}{Energy} ) is a means of communicating the factors of which CO2 emissions are comprised, in order to explain the physical levers that are available if one wishes to control an economy’s CO2 emissions.”
As Willis points out, this is just an identity equation. The fallacy, however, is not just that it is an identity, but that these are levers that are controllable independently.
If you kill off a sizable portion of the population, GDP per population, energy per unit of GDP, and CO2 emissions per unit of energy will all change (and it likely will depend on who you kill off). On the other side, a growing population will have more intellectual capital and vigor and may come up with much more cost- and energy- efficient means of production. Similarly, a change in energy use per unit of GDP will affect GDP and in the long run have some (unknown) effect on population and a change in the emissions to energy use ratio will affect GDP and population. These are all things you can calculate after the fact, but not things you can control.
As an example, you may be able to find a more energy-efficient way to make beer. That method may increase or decrease CO2 emissions per beer (may require different processing or farming methods) and depending on the cost effects may increase or decrease GDP (more or less expensive beer will change consumption). If more or less beer is consumed, that may affect the population growth of the country, both directly and as a function of disposable income.
It is the conceit of the statists and their limited stage 1 thinking that these are levers they can control.
Will @10:21pm:
There are two different “populations.” One is the aggregate population, the other is a population of 1 person. Specifically, the denominator is per head. Same for all the other variables.
The problem arose because the equation was written as though the numerator of one fraction were equivalent to the denominator of the next one. They are not equivalent. They are of the same type of unit, yes; but not the same quantity of those units.
“Goes for the CO2 also, CO2 emissions has to be the same on both sides of the equation.”
Nope. The left side is CO2(Total). The right side is CO2(per energy unit).
climatereflections says “Nope. The left side is CO2(Total). The right side is CO2(per energy unit).”
That is what it was perhaps meant to be, but it is not what we are discussing.
http://en.wikipedia.org/wiki/Kaya_identity
What we are discussing with considerable glee is that it seems some people, maybe many, really have no clue and actually prefer the elegance of a formula that cancels out to itself — namely, an “identity”. If it didn’t, how could you call it an identity? It would then simply be a formula or equation, which are really the same thing except equation names the thing the formula calculates.
The intended formula is simple, obvious and still not all that meaningful since it is filled with assumptions.
Here’s an explanation of the “identity” complete with dozens of charts and graphs all given meaning by — nothing!
http://www.manicore.com/anglais/documentation_a/greenhouse/kaya_equation.html
But it’s very cool. To the casual observer it would look like this self-canceling formula really is a huge advance in science.
Doug says “that greater GDP leads to more energy use” without any qualification. If this were true Italy would have a greater GDP than France. There is no reason this should be true. It may be true sometimes, but it is not true all of the time. Surely many on this forum can provide counter examples both to this assertion and the unqualified assertion “that more energy use leads to more CO2 emissions.” Neither claim nor the supposed Kaya identity account for substitutions. If the Kaya “identity” says anything at all, which is doubtful, it states the obvious; it’s nothing handed down from a mountain top.
Robert Boyd says:
You don’t get it. An identity is not what you think and does not work the way you think. Read what Plain Bill wrote at http://wattsupwiththat.com/2014/07/12/the-beer-identity/#comment-1684795 because he gets it. Then tell others. If everyone helps just two people per day understand identities and how they work the entire world will get it by the end of next week.
JJ says:
July 12, 2014 at 11:33 am
My point has not changed in the slightest, nor have I “walked away” from anything. I never said, however, that “everything cancels so it must be wrong”. That’s just your curious fantasy.
JJ, point out to me in the Kaya Identity where I can find all of the CO2 from gas flaring all over the US.
Point out to me where in the Kaya Identity are the megatonnes CO2 from the coal mine fires that have been burning for decades in China.
Point out to me where in the Kaya Identity I can find the gas I burned today on my vacation. Now, if I had burned that exact same gasoline in a furnace and made a product, it would show up in the GDP part of the Kaya Identity.
But it doesn’t show up in it anywhere … and there are millions of people driving around the US on their vacations.
My point regarding the Kaya Identity is the same it has been all along. It is no better than the Beer Identity, because it doesn’t show or demonstrate or prove anything, and it doesn’t represent the real world. If you think it does, point out to me the CO2 I specified above.
w.
Falsify This:
Klimut Science = CO2 = GDP / CO2 = Bullshit produced * $ / CO2 THEREFORE: CO2 * Klimut Science = Bullshit produced * $ AND: Klimut Science / $ = Bullshit Produced
climatereflections says:
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Sorry man, I flicked by a response you had to me and now I can’t find it again. I am in a bit of a rush.
You said P does not equal P. But I say P does equal P.
Capita means P.
GDP/1 person is not helpful.
It is GDP/capita…..
Thanks for the correspondence. Sorry for the lack of reference to your comment. I wish the comments were numbered.
Will Nelson
PREDICTION: If it hasn’t happened already, some A-Hole ‘Economist’ will tell us how much each Government-Imported Illegal Alien ‘Contributes’ to GDP and another A-Hole Climate scientist will tell us how each Illegal Alien’s ‘Carbon Footprint’ has been reduced by virtue of relocating to the U.S.
William C. Rostron says:
July 12, 2014 at 9:16 am
You guys are missing the point. If I burned that same gasoline to produce something useful, it would be part of our Gross Domestic Production.
But I didn’t. So the burning of that gas doesn’t show up in the GDP … and it also doesn’t show up in the Kaya Identity.
w.
THEREFORE (and this is a problem) The more $ spent on climate science, the less Bullshit produced – unless, of course, Climate science becomes more ‘Efficient’, in which case more Bullshit is produced. (per $).
joshv says:
July 12, 2014 at 9:39 am
So, I see that you are unable to read. As I said above,
Go away until you can grasp the subtleties of that paragraph. I am not interested in discussing your fantasies of what I’ve done or not done.
w.
Willis is right – when I was parking cars for Minimum Wage, I wasn’t producing Jack. And when I’m sitting on my fat arse at 41,000 feet with the Autopilot on burning 300 Gal an hour, I’m not producing Jack.
Al Gore = Couldn’t hack it as an Economist.
Richard:
You begin your post at July 12, 2014 at 10:52 pm saying
Yes! That is an illustration of my objections to the so-called Kaya identity.
Advocates of the equation presented as an “identity” assert that the “ratios” provided on its RHS are “meaningful”. But that assertion is ‘Alice in Wonderland’ logic.
The advocates have not explained what they mean by “meaningful”.
They have not explained how and why any of the the ratios in the Kaya identity is “meaningful”,
and they have not explained why other components would not be “meaningful”.
Furthermore, why ratios?
I have repeatedly argued that the equation is useless and misleading nonsense except as a propaganda tool: the ratios are arguments propagandists want to promote, and a claim that a ratio is “meaningful” is a statement that there is a desire to promote it.
Importantly, the fallacious Kaya identity needs to be rejected now because otherwise it threatens to become THE propaganda tool used to revive the ailing AGW-scare.
Richard