As many readers know, there was quite a hullaballo over the Kaya Identity last week, two posts by Willis Eschenbach here and here created sides seemingly equally split on whether the equation is useful or not.
One of the most strident critics was Dr. Roger Pielke Jr., and in the spirit of keeping an open mind on the issue, I offered him space on WUWT. Here is my email and his response, reprinted with his explicit permission.
On Mon, Jul 14, 2014 at 9:52 AM, Anthony xxxxxxx@xxxx.com wrote:
Hello, Roger Jr.,
I’d like to direct you to a comment on WUWT that challenges your calculations using the Kaya Identity.
http://wattsupwiththat.com/2014/07/12/the-beer-identity/#comment-1685623
I provide it only for your information.
I know both of you have issues with the current state of discussion on WUWT regarding that equation/identity/relationship, and I’m certainly OK with that.
I think that much of the dissent over it has to do with the difference in viewpoints between science and engineering. I and many others look at the Kaya identity equation more from the engineering perspective, and expect it to perform as many other calcs do, but it seems that it doesn’t act as a hard equation, but more like a soft one, that generally defines the relationships of terms. A number of commenters have approached it from the engineering viewpoint, and find themselves puzzled as to why the numbers they get don’t seem sensible.
I puzzle over that also.
To that end, and because you’ve been highly critical, agreeing with such statements as “breathtakingly ignorant”, therefore, given the critical comment above, I’d like to offer this, first raised in another comment:
http://wattsupwiththat.com/2014/07/12/the-beer-identity/#comment-1684325
Perhaps Anthony could give equal time to Pielke in defense of the Kaya identity?
I’m more than happy to do so should you be so inclined; not just for my own education on the topic, but for the hundreds, if not thousands of others that suffer from the same doubts that the equation isn’t as well thought out as some claim it to be. Or, if it was never intended to produce real world numbers accurately, but serves only to illustrate the relationship of the variables, explain that clearly so that the engineering types understand it better.
If you wish to make a submission, MS Word with embedded images works best. Any equations you might want to use in MS word’s equation editor don’t translate to WordPress well, so they will be converted to images. Or, you can optionally use LaTex, which is supported directly in WordPress.
I would appreciate an answer, no matter if it is a yes or a no. Thank you for your consideration.
Anthony Watts
=========================================================
Roger’s response Tuesday, July 15, 2014 6:59 AM (published with permission)
Hi Anthony-
Thanks for your email. Apologies for the delay in responding, as have been off email while traveling.
If you’d like to help your readers better understand the use of the Kaya identity, which I think is the most important tool for analyzing actual and proposed carbon policies, then I would recommend that you introduce them to this paper (open access);
http://iopscience.iop.org/1748-9326/4/2/024010
The mathematics are simple. Of course, there is a more in depth discussion in my book, The Climate Fix.
Finally, for those who’d prefer a lecture format, here is me at Columbia Univ last summer explaining the significance of the Kaya Identity for climate policy analysis:
Thanks, and all the best,
Roger (Jr.)
==============================================================
I agree with Roger that: “The mathematics are simple.”
In fact I think it is that simplicity that lends itself to being criticized as not being fully representative of a complex system. Willis described the Kaya Identity as being “trivially true” while Roger in his book and video treats its with the same respect as some physical law equation. My take is that the truth is somewhere in the middle between those viewpoints.
Whether it is best used as a political tool or as a physical science tool is still an open question in my mind, though I tend to think it leans more towards political usefulness. Whatever your viewpoint is, let’s thank Roger Pielke Jr. for taking the time to respond and to offer his view here.
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“I would point out that based on the “Kaya Identity”, doubling the population while keeping gdp, energy consumption, and efficiency equal results in zero increase in CO2 emmisions. I guess CO2 is independent of population.”
Only if you use the incorrect understanding of Kaya. With the the correct understanding: CO 2 emissions can be expressed as the product of four inputs: population, GDP per capita, energy use per unit of GDP, and CO 2 emissions per unit of energy: then doubling population while holding all other terms constant will double CO2.
“In the case of this report, as this was written for the Brits all I can conclude is that it makes the British Government look pretty good compared to some others and that was the intention of the iBrits in the first place.”
on the contrary
nutso fasst says: July 19, 2014 at 10:36 am
“Agree. The Kaya Identity helped Pielke memorably demonstrate that the UK cut their CO2 emissions primarily by making the nation poorer, not by filling the countryside with wind turbines.”
According to the link given by Dr Pielke, and the graph supplied therein, China has the highest rate of emissions per $1000 GDP but they also have the lowest rate per capita, although no mention of this in the article that I could find.
http://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita
According to this source, China is 20% behind the EU and closing fast on per capita CO2 emissions. The US is twice the EU,
Yes, thanks, Dr. Pielke, for responding.
(Snip -off color comment -mod)
“Only if you use the incorrect understanding of Kaya. With the the correct understanding: CO 2 emissions can be expressed as the product of four inputs: population, GDP per capita, energy use per unit of GDP, and CO 2 emissions per unit of energy: then doubling population while holding all other terms constant will double CO2.”
The “Kaya Identity” is misunderstood when it is poorly stated.
1) it’s not an identity, it’s an equation;
2) the equation is stated with units only, not variables.
With the correct equation presented, it will be correctly understood. The proper way of writing out the Kaya Equation is:
F = P*g*e*f
It is left as an exercise for the reader to understand that because the Kaya Equation is *not* an identity, it cannot be constructed algebraically from CO2 = CO2.
I offer my sincere apologies for over-stepping the mark earlier on.
krishel: Please correct in the Wikipedia.
Curious George says “krishel: Please correct in the Wikipedia.”
You can do this yourself. *I* could do it. Anyone can do it but the warmists love it the way it is and the skeptics rather enjoy it too. I’ve got my screenshot and when it changes (if it changes), I’ll screenshot it again to show the workings of the Ministry of Truth.
Total CO2 is what is used to find the CO2/energy term. That it comes from adding up a few sources does not change anything. Kaya does not separate the sources, it only uses the CO2 sum divided by the energy sum. In both cases those numbers are probably WAGs, but that’s another matter entirely. Even if they were dead-on accurate, Total CO2 is needed in the right hand side of the equation. So you have Total CO2 = f(Total CO2).
Krishel says @July 19, 2014 at 1:40 pm:
And followed it with a self-fulfilling example.
Total CO2 is what is used to find the CO2/energy term.
Hmm. How is total CO2 determined/measured if not as I described?
RobertInAz says: (July 18, 2014 at 11:48 pm) “In which case, every identity that forms the basis of modern physics is circular logic.“. Not at all. In a normal physics ‘identity’, each factor brings something new to the equation without taking anything away. In the Kaya formula, each term from the second onwards takes away a factor from the previous term, until there is nothing left but what it started with. As I explained, taking GDP per person for example, we don’t know GDP per person in its own right, if we did then this part of the equation would be valid; we only know it as total GDP divided by total population, and therefore the terms cancel out.
“You make the same error as Willis when you say: “So the exact same number that goes into the ‘top’ of one equation goes into the ‘bottom’ of the next equation.” The correct description is: “The units of the variable at the top of one term of the equation are the same as the units of the bottom of the next term of the equation. In physics, we confirm our equations are right when the units on the right cancel out to equal the units on the left.“. Of course the units have to be the same right and left. But that’s not the point. The point is that in the Kaya equation the quantities are necessarily exactly the same ‘top’ and ‘bottom’ and hence add nothing to the equation.
—
What the Kaya equation seems to be trying to say is that CO2 emissions can be reduced by reducing total population or GDP per person or energy per dollar of GDP or CO2 per watt. That’s all true, but not very helpful. For example, CO2 emissions can be reduced by replacing old coal-fired power stations with new ones or with gas or nuclear, improving house insulation and using passive-solar design, sending freight by rail instead of road, repairing roads faster or making traffic lights more efficient – or even by improving girls’ education. Sure, each of these can be mapped post-facto to one or more of the terms in the Kaya equation, but the equation didn’t help and doesn’t help.
I see a lot of ‘mathematicians’ apparently unable to figure out that Kaya is a simple tool that uses statistics to help people reason about policy implications. (Does anybody seriously believe that Pielke sees Kaya as akin to the laws of physics? Good lord.) It shows policy makers that they have a choice: if they want to reduce emissions, they can either bankrupt their countries, or they can focus on energy innovation.
I also see a lot of people who are having allergic reactions to the idea of “government interference”. Right or wrong, the “do nothing” option is not on the table, nor will it ever be on the table. If governments are implementing policies to reduce CO2, I would much rather see them shift the bulk of their efforts towards energy innovation.
JamesNV says Right or wrong, the “do nothing” option is not on the table, nor will it ever be on the table.”
Oh? How did you happen to become Keeper of the Table?
So what’s the point of reducing CO2? Obama/EPA limited US power generation to 1,100 pounds CO2 per MWh which will make a 2.2% difference in global CO2. Big deal! Why are governments compelled to reduce CO2?
If one were to express the Kaya Identity if text form it would be something like:
Carbon dioxide emissions are directly related to energy use, GDP and population.
And it would be undeniably true, as a rough rule of thumb.
Instead it is expressed as a series of precise, directly proportional numeric relationships, intended to impress the innumerate with its precision and by extension accuracy.
This is closely akin to the neophyte with a calculator who believes that because he saw 5 events in 7 seconds that they must occur every 0.71428571428571 seconds and that the last digit is significant despite the lack of precision of the input.
It is also a generalization beyond what the evidence supports.
Specifically, the claim that these factors are directly proportional is obviously false. They all require the stipulation that ‘all other things being equal’ which is never true. If for example, population increases, some things become more efficient (transportation) others might become less efficient (results of land use pressure).
These factors make the Kaya Identity as valid and useful as the statement that 77 degrees Fahrenheit is 10% hotter than 70 degrees Fahrenheit. It is neither precise, accurate nor true, but perhaps 80% of the people will believe it because it looks mathematical.
“the Kaya Identity as valid and useful as the statement that 77 degrees Fahrenheit is 10% hotter than 70 degrees Fahrenheit.”
Or that 1 degree F is infinitely hotter than 0 degrees F!
RobertInAz says:
July 18, 2014 at 11:59 pm
“In defense of the report, the description immediately before the ambiguous equation was correct:
“we simply refer to them as CO 2 emissions. CO 2 emissions can be expressed as the product of four inputs: population, GDP per capita, energy use per unit of GDP, and CO 2 emissions per unit of energy: “”
And now, let’s apply the “Tools in the toolbox”, as the warmist sociologists love to call them:
a) Population. That’s easy: Smallpox and civil war should take care of that.
b) GDP per capita: We know what to do about that: Abolish profits, equal pay for every job, killing every incentive to be productive. Cuba leads the way.
c) Energy Use per GDP: EU just decreased that by adding blow and hookers to official GDP. Easy as cake!
d) CO2 per energy: Ok, that’s complicated. One needs brains for that. No tool in the policy toolbox. a,b and c should suffice.
John Brisbin says: July 19, 2014 at 4:02 pm “It is also a generalization beyond what the evidence supports.”
On the contrary, Kaya reflects real world data (see Ruth Dixon: http://mygardenpond.wordpress.com/2014/07/13/a-graphical-look-at-the-kaya-identity/#more-706 )
The key point is for a particular country, Kaya holds for the purpose of policy analysis. It is not a perfect tool. What tool would you suggest to help policy makers understand the cost of mitigation?
RobertInAz says “What tool would you suggest to help policy makers understand the cost of mitigation?”
No tool exists. Mitigation of a naturally occurring substance, CO2, has never before been attempted on a large scale. Consequently you come up with an idea and let the idea reveal the costs.
Kaya is useless. It is because the terms cancel that what you are left with is exactly one factor — the CO2 efficiency of energy. Until and unless you have “carbonless energy” all other approaches are doomed. You don’t need Kaya for this.
Mitigation – of what? Why? CO2 does not equal warming does not equal apocalypse does not equal any needed policy “mitigation” solutions. First step in a solution is making certain you have the correct problem. What does the Kaya tell policy makers they need to do? Why do the “policy makers” need to do anything??!! Too much time on their hands? Trying to insure their “legacy?”
Absolutely astonished that wuwt continues to even entertain this complete nonsense.
Yes, Kaya is an identity, but it is also a tautology: it conveys no wisdom and has no utility at all, in stark contrast to Newtonian mechanics, Maxwell´s electro-magnetics, or Einstein´s mass-energy relationship, for example, which were also expressed as simple equations, but had insight and made us wiser and helped catapult us into modernity.
Kaya is of the pure crap pseudo-science category that usually only finds an audience among scientifically/mathmatically illiterate enviro-fascist art-school student types and climate scientists.
nickreality65, The reality is that policy makers believe it to be a problem. So they ARE going to do something about it. What would you rather them do? ‘Investing’ in energy innovation, research and development is not necessarily a bad idea regardless of CO2.
JamesNV says “Investing in energy innovation, research and development is not necessarily a bad idea regardless of CO2.”
Quite right. Fossil fuel will run out. Substitute is needed. However, since the cart was hitched to a gimpy horse, now that the horse appears somewhat crippled it may be hard to move that car.
Looking at the past decades of alternate energy “investing”, yeah, it can be a bad thing. A massive waste of resources. I remember the big solar boom of the seventies. How many of those systems have been abandoned? Such “investing” diverts resources from real problems. A natural museum recently opened nearby with a nice gift shop. I can think of no greater harm to the environment than the production of a lot of useless crap – and wind and photovoltaic and CFL “investments” fit that description.
I’m enjoying the scientific “macho men”, strutting around showing off their “hard science” cred, aggressively dismissive of “fluffy” things like economics, art and psychology because it’s so “soft” (maybe a little too feminine?). Seems a bit neurotic. 😉
says the pot
nickreality65, when I said not ‘necessarily’ a bad idea, I was thinking nuclear.
megawati says: July 19, 2014 at 4:24 pm “Yes, Kaya is an identity, but it is also a tautology: it conveys no wisdom and has no utility at all,”
Dr. Pielke has documented many cases where Kaya provides useful insight. Perhaps you could explain where he is wrong. Did you read them? Did you read my explanation on how many WUWT readers (starting with Willis) misunderstand Kaya? Which understanding of Kaya are yiou basing your assertion on?
“Kaya” is a political tool that, in the worst case, can actually be allowed to kill people in the name of “saving the planet”.
RobertInAz says “Dr. Pielke has documented many cases where Kaya provides useful insight.”
Has it convinced anyone not already convinced of the “A” in “GW”? I don’t know, seems iffy.
“Perhaps you could explain where he is wrong.”
He illustrates that the terms cancel right in his program leaving “C = C”. You can insert anything at all in the middel so long as it cancels. If the thing you inserted happens to be explanatory, that’s fine, but you don’t need this “device” or gimmick. Just explain what you intend to explain.
“Did you read them?” yes.
“Did you read my explanation on how many WUWT readers (starting with Willis) misunderstand Kaya?” Yes. You show algebra then explain that it isn’t algebra. Very clever!
“Which understanding of Kaya are yiou basing your assertion on?”
Mine (of course). The same is true of everyone commenting on it, each is commenting from his own understanding of it.