It is time to stop quivering in our boots in pointless fear of the future and just roll up our sleeves and build it.
- Ray Pierrehumbert

Monday, May 5, 2008

Mashey Summarizes Carbon Urgency

Another excellent effort from John Mashey that he has honored my comments section with is quoted in full below. Now, it's a bit imperfect; point 9 could be clearer, and point 10 appears to be totally missing. My attempts to prettify the nested list structure (a sure sign you are dealing with someone who has written some code in his day) inside the blogger interface were too frustrating to persist with.

Point 8, though, ah, point 8 is a thing of beauty. I haven't seen it put that way, but it seems pretty compelling.

It happens that I agree with all of it, though I wasn't aware I agreed with point 8 before reading it.

Perhaps point 10 is so important that, like the twentieth principle of the Zen of Python, it is never written down.

John Mashey says important enough things often enough that I think he ought to have his own blog, but meanwhile, if he cares to honor my comments section with stuff this good I at least ought to call your attention to it. Everything that follows is John's commentary, and not mine.

1) Given the history of AEI & WSJ Op-ED, it is very likely this is a "misdirection" argument, even if pieces of it are certainly true. I.e., it's like Lomborg's arguments - see my recent comments over at

2) But in any case, to be clear, most of the economic arguments I've seen seem very dubious to me, in that they:

a) Model the US economy via typical neoclassical economic assumptions

b) Which means ~3% GDP growth, more or less indefinitely

c) of which 1.5-2% come from "technological progress" or "Total Factor Productivity" or "Solow Residual" ... See for example

To me, this means: we' don't really understand it, but it's been that way, so it will be that way.

3) If past data more or less fits a straight line (for decades, or as in the US GDP case, for ~100 years), then the natural prediction is to predict it to continue indefinitely.

4) If it's more or less a straight line on a log scale chart, it's exponential growth with an approximately constant CAGR, and the temptation is to predict it to continue.

EX: Moore's Law for semiconductors

5) INFLECTION POINTS: if one just does mathematical predictions, without relevant physics underpinnings, one would predict Moore's Law to go on forever. It won't, but it is nontrivial to predict inflection points, and worse to analyze multiple trends and their inflections and make good bets.

6) The "biophysical economists", like Charles A. S. Hall, Robert Ayres+Benjamin Warr, Vaclav Smil, etc, think that a lot of that "Total Factor Productivity" is really:

useful work = energy * efficiency,

with perhaps a bit of a residual boost in the last few decades from computing. I think they make a very good case for it, but then I'm not an economist.

I do observe that the UK got rich in part because it was early to exploit coal heavily, and the US likewise, but for oil.

I also observe that:
- subsistence farmers with nothing but human labor, tend to be poor, but it's why they often have big families.
- farmers with draught animals usually can grow more; many poor farmers would consider the Amish lifestyle unimaginably wealthy, with say, 60 acres/family.
- farmers with electricity, diesel fuel, tractors, and combines do OK, and can (in mid-West) handle hundreds of acres of wheat or corn, and do pretty well.

7) But, if the biophysical model of the world is a better approximation than standard necoclassical, then Peak Oil+Gas is the biggest inflection point in recent history, and all these happy 3% CAGR predictions are ...useless...

8) In that case, it isn't a question of "how much will it cost", it's a question of "can we move fast enough on efficiency and renewables, and *invest* the oil+gas that's left (about 50%) so that there's an above-subsistence economy left when fossil fuels are gone?" (and not be driven by desperation into massive coal-burning). And can we avoid building infrastructure and vehicle fleets that are instant "stranded assets"?

9) Put another way: in the standard neoclassical model, an airplane can keep accelerating upward without burning fuel. Very happy.

In the biophysical model, acceleration depends in large part on increasing fuel * efficiency. In the next decade, fuel starts going down, and then accelerates downward. The plane's eventual altitude depends on the ability to increase efficiency ... and over the next century, replace the 2/3 of US energy from oil+gas. Sad, but true, if one tries to keep acceleration going as fuel diminishes, you can actually damage the engines. [If you try to extract oil too fast from a field, you can damage the oilfield and get less total oil.]

11) Assumption of ~3% growth is built into many plans. I hope it happens ... but personally, I think even folks like Stern are underestimating the problem and the urgency of moving REALLY fast.


Anna said...

> "...the temptation is to predict it to continue."

cf. Alan Alda's All laws are local.

Marion Delgado said...

The denialism squad is moving more rapidly into 2nd (fallback) fortifications. Surely, they say, reasonably, you will admit that the consequences of global warming are minimal and the problem is not as bad as you said it was. Next it will be the usual economic quibbling.

We just have to stick to our guns. First of all, absolutely none of us are pleased that conditions are actually worse than we predicted they'd be, almost across the board. It's sickening and terrifying that allegedly thinking beings would believe that, even.

Second, absolutely everything involved has to be on the table now. The possibility that the sun will give us a break, and making sure we use it if it happens. The amount of heat already sunk into the ocean. The amount of CO2 already sunk into the ocean. The amount of heat sunk into melting ice. The changes in currents, in albedo, in forestation. The issues with increasing particulates artificially and the effects on breathable air and the ozone layer, and so on.

We can't look at the issue reasonably if every single positive feedback mechanism has to be looked at in isolation. And most of the mechanisms involved with climate change are positive feedback mechanisms.

Michael Tobis said...

"And most of the mechanisms involved with climate change are positive feedback mechanisms."

It seems that way, doesn't it? And yet the biosphere has persisted over a billion years. It's a bit confusing really.

Of course there is Lovelock's Gaia hypothesis to explain the past, and Lovelock is hardly an optimist about the future. He is a bit of an outlier in many ways, though.

I don't know if we've hit the iceberg yet, but somebody ought to tell the captain that full steam ahead isn't a good plan.

Only economists claim to be able to think effectively about everything at the same time. They do that by ignoring almost everything, and have gotten away with it for a little while, but that luck seems unlikely to persist.

Those of us who don't want to exclude anything much a priori have a very hard problem.

John Mashey said...

Thanks for the kind words. Had I known it would get promoted, I wouldn't have dashed it off, and mis-edited 10 out ... because it was important. I reconstruct it below.

First, though, item 9 is confusing because it really needs a graph, of which the closest approximation is the last page, p.45 of Ayres PPT
or p.34 of Ayres paper:
I suggest printing that page so one can draw on it.

The vertical scale is the size of the US GDP relative to 1900. The 3 lines are the modeled GDP, with low, medium, and high efficiency improvements, which PEAK at (by eyeball):
2010 23X (i.e., a bit above 2005's 22X
2020 26X
2035 34X

2030 45X what 3% CAGR would give
(draw that curve from (2006,22) to (2030, 45). Something like that curve *appears* to be in the usual economic models, of which a nice collection is described in:
It's more or less what's in IPCC and Stern.

Now, the airplane analogy may make more sense, because it was derived from looking at the resulting chart.
In this case there are 4 different paths, one of which ignores Peak Oil+Gas, and the other three don't, but vary on how good we dod with efficiency.

One can read the Ayres PPT, or the paper (some econ math helps for the latter, but it does have more words). THEN, one can decide whether to be nervous or not. Recall that many economists think that the descendants will easily be so rich they can afford to fix problems they inherit, and they seem to think so because the plane has been rising for a century.

And the missing 10 + a few other words, accidentally cut. Goes just before 11.

Think of this as a stall.

In any case, long-lasting fumes slowly build up in the cabin, tending to sicken passengers earlier in Coach, but eventually reaching First Class, and too much exposure kills. Fumes react with the cabin, releasing yet more fumes via positive feedback.

10) Also, the plane has some alternate fuel (Coal) used along with the orimary fuel. It's cheap, and may keep the plane going longer, but it creates fumes even faster. The mixture is partially controlled by passengers.

If people are desperate to climb, or counteract a downdraft, and burn a lot of it, passengers start choking. In the really worst case, if fume-feedback crosses the wrong tipping points, many will eventually die, although not quickly, and everybody will fight for the better air at the front, because they'll know what's coming.

Alternatively, IF
- the good fuel is used to keep the plane high enough to do a solar conversion in mid-flight
- and carefully stretched to allow time to do it
- and everybody helps
- and nobody thinks that fuel is irrelevant for the plane

THEN maybe the plane stays at an acceptable altitude after the fuel is gone, although the easy, high accelerations are gone.

[This analogy is by now stretched pretty far.]

Steven said...

I believe economists specifically claim exactly the opposite. No one can think effectively about everything at the same time.

How do you solve that as a programmer? Distributed processing.

If you were in a Python programming contest, which would you prefer:
1) First pick for your team.
2) Unlimited submission of your entry for feedback and retuning?

I submit you would take the lesser team and iterative feedback. You can claim to deny market principles, but I doubt you frequently act in opposition to them.

Michael Tobis said...

Steven, when you say what economists believe, I think you are confusing the academic discipline with your ideology, the one that readers of the National Review or Reason might hold.

Academic economists are happy to build what they call "integrated asssessment models". If you want to give some academic computer models a hard time, go look at those.

Of course you are preaching to the choir about distributed processing and about iteration/agile development.

I am a bit tired of your straw man arguments already. Please actually respond to what I actually say I believe, not what you think I believe.

The whole point here is we need a transition to a sustainable steady state (as far as material flows are concerned). Nobody here is arguing for a transition to a control economy, least of all Mashey.

If you are the sort of person who likes arguing against communists, you ought to go somewhere else and find some.

David B. Benson said...

Georg Ch Pflug & Werner R{umlaut}omisch
Modeling, Measuring and Managing Risk
World Scientific, 2007.

Mathematical treatment of risk measures (risk functionals).

Steven said...

As I've said before, I can only represent what I believe in. I think you'd consider it fair that people don't lump your individual positions in with any outlier who claims to be similarly representing AGW.

A lot of people claim to sucessfully use economic models to predict the future. A lot of people claim to talk to dead loved ones of paying audience members. We remember the hits and forget the many, many misses.

I've never liked the phrasing of the economic rule "People act in their own self interest".

My first rule of economics is that all human beings inherently seek to better themselves. This is why, overall, I am an economic optimist.

Marion Delgado said...

I always thought the lovelock-margulis gaia hypothesis was interesting. I do believe if we could stop bringing extra carbon into the atmosphere completely for a couple hundred years that the natural systems would probably return conditions to the status quo.