The only thing we can be sure of about the future is that it will be absolutely fantastic. So if what I say now seems to you to be very reasonable, then I have failed completely. Only if what I tell you appears absolutely unbelievable, have we any chance of visualizing the future as it really will happen.

- Arthur C. Clarke (h/t Brin)

Tuesday, January 19, 2010

The Pink Line

Part I: Incoherent Arguments

So during the Luciagate episode, I wandered over to Lucia's to see what she was up to. Read through the comments (especially the second half) to see the result.

Lucia is at least a semiregular reader here, but I can't say I reciprocate. Though she seems a pleasant enough person, she is very much in the grip of the conspiracy theory view of climate science and in particular the idea that McIntyrean hairsplitting is of the essence. I've always been a kind of a top-down guy myself. I find the whole baseball statistics approach to climate tiresome and, sorry, shallow.

So if you go look at the people who took me on, you will see some classic examples of some of the various naysayer species, all getting along, and all saying very different things. There is Kentucky Andrew whose strategy is simply that of a three year old: why? why? why? and prove it! prove it! prove it! Therefore Not the IPCC. This kind obviously has zero capacity to listen to any answers. Even Lucia expresses exasperation with this specimen.

There is the Russian mathematician type. If this isn't just one guy with three aliases, this is the third example of this type I've encountered. There is a rich literature of the mathematics of nonlinear dynamical systems which I have never been able to penetrate. It is amazing that people who accuse us of arrogance make common cause with this type of person whose main point is that I don't know their theorems and haven't read their papers, so who the hell am I to claim I know anything about climate.

My answer is that the relationship between their field and the one we care about is much more remote than they believe, so their theorems avail them naught. They say, well, of course our theorems do not apply, your system is too messy and therefore you know nothing. Therefore we should act as if the sensitivity is zero, therefore Very Not the IPCC. (Since they tend to be emigres from Soviet Russia, they may throw in, Lubos-like, a dig about our supposed Stalinist motivations.)

The third kind is the "throw spaghetti at the wall" type, the one who will wheel out fifteen half-baked arguments for every one you try to refute. This kind seems the most thoroughly trained in political shenanigans. The approach is as common as it is frustrating. They refuse to play by anything resembling the rules of logic, instead resorting to pure polemics. If you score a point of any sort, they will pretend not to notice. Therefore Very Very not the IPCC.

The fourth kind is the tantalizing sort like Lucia herself or others you see on CA or Blackboard. They are polite, considerate, and show every sign of seeing your point. Then they proceed to ignore it or forget it had been made. They are a great pleasure to talk to, at least relatively speaking compared to the other sorts, and they will not actively subvert your appeal to neutral readers. But somehow like in an Escherlike endlessly rising staircase, their pleasant small concessions never amount to a movement of position. Anyway, you will find them stubbornly sticking with Very not the IPCC and now Very Very not the CRU.

Actual debate seems quite unheard of on these sites. You will only find actual debate among people with an inclination to think. The press calls this sort of constructive debate "disarray" or such, by the way. This is one of the most irritating things about the journalistic approach, where rabid certainty is treated as somehow better than, um, reason. In their view, a club of lunatics humoring each other is somehow more impressive than people who constantly challenge themselves and each other.

Now at one point, Eli thanked me for the word "coherence", as a description of what we've got that the other guys ain't got. But I have been mocked by them for using such a big word, a word whose meaning is so non-obvious. Fortunately, I have some examples.

One came up in the conversation at Lucia's. It appears that the climate catastrophe at the Paleocene Eocene boundary yielded an increase rather than a decrease in terrestrial animal biodiversity. It says so on Wikipedia and my attempts to find credible supporting evidence were in fact successful. It appears that the evidence supports this increase in species diversity at the PETM.

One DeWitt Payne uses this to argue that climate crises are good for you if you are a mammal. This set me back for a bit, since it seemed incoherent. Intrinsically, a climate crisis must be worse than a stable climate; it must be a stressor for well-adapted species. But then I noted that it is stressed species with small breeding populations that tend to speciate. So the fact that the number of land animal species emerging from the PETM was larger than the number going in would have to mean the viable populations had been fragmented and diverged. (Whereas the decline in ocean species simply meant that ocean life had nearly been wiped out.) The number of species in non-crisis circumstances is nearly constant. Both increases and decreases in species count demonstrate stress, and both demonstrate decreases in the population of the various species at the time. So rapid climate change is not actually a good thing. It wouldn't make sense, and so it's not surprising that there's an explanation as to why it isn't what happened.

Nature is coherent.



Part II: The Pink Line

So today I found myself thinking about this figure from AR4:

I had seen this figure several times and had long had a coherence problem with it. I had been taught in the 1990s that temperature increases had a twenty to thirty year lag; in other words, to find warming that is inevitable today (even if all emissions ceased instantly) you would extrapolate the roughly exponential black curve a quarter century forward, and read the temperature from there. Yet the pink line in the IPCC figure shows an increase of somewhat less than half that, attributed to Hansen et al 2005. And I had not heard any changes in the estimated warming "in the pipeline". Had I missed a major change in the consensus?

Today, I decided to have a closer look and try to resolve my confusion. It turns out that the Hansen result assumes "no changes in atmospheric composition", not "an abrupt end to combustion". In other words, the somewhat implausible scenario that dust emissions stay constant (since dust settles out quickly) while CO2 emissions go abruptly to zero (since CO2 lasts a very long time) is portrayed. This understates the committed warming, since everyone expects aerosol concentrations to decline as pollution controls get put in place in developing countries and as shifts to non-carbon-based power proceed.

It turns out on discussion with my fellow bloggers that Zeke Hausfather has already thought this through and has reached similar conclusions.

I am surprised and astonished that the IPCC critics have not been all over this, since it amounts to a systematic underemphasis of climate related risk. The pink line should really climb much more steeply. As you will see from Zeke's article, we are already committed to warming very close to the Copenhagen threshhold.

Given how excited IPCC critics get about every case where an aspect of climate risk is arguably overemphasized, you'd expect them to be equally up in arms about this case where the risk is very seriously underemphasized. Perhaps they missed this one. I await the IPCC critics' vigorous and constructive critique of the IPCC's understating climate risks on this graphic.

Anyway, and here is the point, when you have actual scientific knowledge, information from one source or topic can and should influence your thinking on others. Thus a coherent worldview arises. The naysayers on climate change lack a coherent worldview. Their claim is that climate has some magical properties making it unapproachable by science, and that thus very little can be known. But all they know for a fact is that they themselves know very little. Those of us who know enough are uncomfortable with bits of information that don't fit in right. Our experience is that if we look closely enough, there is usually a difference in assumption or nomenclature, not inconsistent evidence. We don't know everything, but what we do know tends to hang together, because we are practicing actual science, not as some philosopher of science would describe it, but as it actually works. Human minds collaborate to produce a robust and coherent view of the world. When we say "I don't believe that" about something or other (even something well argued like for example a Lindzen and Choi result) it isn't bullying or arrogance, though it may sometimes look that way.

What we are doing is relying on the fundamental coherence of nature. It generally all works out in the end.

---
Image from Wikipedia: Pink Line (Chicago Transit Authority) by Nate Beal, (c) (cc Attribution Generic) 2006

29 comments:

Ian said...

Enjoyable post, and I love the typology in Part 1, very clever and apropos.

As for "coherence" in AGW, I think this relates to the low-level skeptic complaint that established science is more critical of non- or anti-consensus results than of results that fit the "coherent" and more established body of findings (e.g., the recent Lindzen & Choi go-round). In part because of the coherence property you mention, it's appropriate to demand more from a contrary finding - it's not a sign of improper bias.

ourchangingclimate said...

Re part 1, I enjoyed reading parts of the conversation at Lucia's, and you made some very pertinent remarks over there about the scientific process. Hope some of it sticks.

Re part 2, Ramanthan and Feng's 2008 (PNAS) and 2009 (AE) papers are relevant:

Global average surface temperatures have increased by about 0.75 degrees Celsius since the beginning of the industrial revolution, of which ~0.6 °C is attributable to human activities. The total radiative forcing by greenhouse gases is around 3 W/m2, with which we have ‘committed’ the planet to warm up by 2.4 °C (1.6-3.6 °C), according to a climate sensitivity of 3 °C (2-4.5 °C) for a doubling of CO2. The observed amount of warming thus far has been less than this, because part of the excess energy is stored in the oceans (amounting to ~0.5 °C), and the remainder (~1.3 °C) has been masked by the cooling effect of anthropogenic aerosols. This simple analysis shows that the ‘2 degree target’ of maximum acceptable warming is looming on the horizon, as the climate equilibrates and aerosol pollution is cleaned up.

Bart

duffandnonsense said...

"Actual debate seems quite unheard of on these sites."

Sounds a bit like Frank Bi's site. All I said was "Hello" and shortly there-after I was banned!

Talking of coherence:

"There is a rich literature of the mathematics of nonlinear dynamical systems which I have never been able to penetrate. It is amazing that people who accuse us of arrogance make common cause with this type of person whose main point is that I don't know their theorems and haven't read their papers, so who the hell am I to claim I know anything about climate. [...] My answer is that the relationship between their field and the one we care about is much more remote than they believe, so their theorems avail them naught."

"Anyway, and here is the point, when you have actual scientific knowledge, information from one source or topic can and should influence your thinking on others."

Presumably that injunction does not apply to the mathematics of nonlinear dynamical systems!

David Duff

Dano said...

I am surprised and astonished that the IPCC critics have not been all over this, since it amounts to a systematic underemphasis of climate related risk. The pink line should really climb much more steeply. As you will see from Zeke's article, we are already committed to warming very close to the Copenhagen threshhold.

I can't imagine why you would be surprised, unless you simply use this as a rhetorical device. Why should you not be surprised? You just spent 1250 words describing how denialists and pseudoskeptics don't have a clue.

Why on earth would you expect them to be all over something that they don't understand, that they haven't been educated in, that they have no interest in finding greater risk for (and thus more impetus for action that they don't want in the first place)?!?!?!?

Best,

D

word verif chastises as well: balecar

Michael Tobis said...

The rhetorical device one.

Michael Tobis said...
This comment has been removed by the author.
Michael Tobis said...

"Anyway, and here is the point, when you have actual scientific knowledge, information from one source or topic can and should influence your thinking on others."

"Presumably that injunction does not apply to the mathematics of nonlinear dynamical systems!"

On the contrary. When you lack scientific knowledge from one source or topic you should not try to apply it to the other. My limited grasp of dynamical systems tells me it is pretty much not all that applicable to the questions that interest the public. The dynamicists say the same.

So neither of us violate the advice.

The problem with the dynamicists as I see it is they pretend theirs is the only approach to truth.

The problem I see with you, David, and increasingly with all the naysayers, is an adamant attachment to a shallow imitation of reasoned thinking, which you display here.

Shallow, contentious, counterproductive and mean. I had thought you a nice fellow, David. Perhaps niceness vanishes when you get sucked into a paranoid view of the world.

You are falling into the group that Stoat's proverb applies to. You are not required to understand everything that goes on around you but you would do well not to pretend that you do if you don't.

David, if you want to continue to participate here, you need, at least for the purposes of civilized discourse, to act as if I know what I am talking about (or at least know when I know what I am talking about) and that I mean well. If you believe and advocate otherwise I am under no obligation to help you advocate your misguided malice.

Lou Grinzo said...

Great pair of posts. Some of the denier debating tactics you describe remind me of one of my all-time favorite quotes, from one of my all-time favorite scientists and communicators, Carl Sagan:

"But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown."

To which I would only add: Sometimes the clowns don't know they're the clowns.

dhogaza said...

Didn't Sagan realize that Columbus was a clown, as well? :) The laughter he got from those asked to pass judgement on his proposal was well-justified.

After all, those who argued that the old estimates of the earth's circumference were mostly right were proven true. Columbus got bailed out because there was an undiscovered continent in between Spain and Asia, not because Asia was as close to Spain as he had argued.

OK, some clowns get lucky and are unreasonably labelled geniuses, I guess.

Deech56 said...

Michael,

Good post. I am intrigued about the approach by self-proclaimed "lukewarmers." The "AGW is happening, but the sensitivity is low." This apparent acceptance of some of the science does not preclude their making disparaging remarks about Mann, Jones, et al. (the book about the stolen CRU e-mails is an example).

I will be interested in your post about the Knutti&Hegerl paper, which highlights the independent ways that climate sensitivity has been calculated.

Someone posted this in the thread at Lucia's place, but here is the pdf for Knutti&Hegerl:

http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf

duffandnonsense said...

Calm down, Michael, if you re-read, carefully, my last post all it does (setting aside my mild tweak of Frank Bi's nose) is quote you and point up what appeared to be a contradiction. No more, no less. For that I receive a stream of personal abuse which, if I used against you, would see me banished to 'Commenters' Siberia'! I say again, calm down because you touch upon a serious, even critical point.

Like you I am not a mathematician but I think I just about grasp the essential thrust of "the mathematics of nonlinear dynamical systems!" particularly in regard to weather and climate. I am happy for you to convince me otherwise but in my opinion it is central to this whole climate debate. All science, in the end, reduces to mathematics because that is the means by which we measure, and measurement was the beginning of Man's first entry into what we now call science.

The one thing the 'chaos theory' mathematicians tell us is that because you cannot know every detail of any opening scenario then the end result of any re-iterated algorithm is incapable of being forecast except in the form (in effect) of Bookmaker's odds and the more reiterations you do the longer the odds of success. That is why weather forecasts are never much good after 3 to 5 days and why attempts to forecast climate in 30 to 50 years are doomed to failure.

The media, in their search for a simplified image with which to describe an extremely complex set of mathematics, talk of the 'flutter of a butterfly's wings in Brazil eventually leading to a storm in Britain. Nonsense as a literal truth, but correct in essence, according to current chaos theory.

Now, I'm not trying to convince you of anything, I'm too old for that sort of effort. I am merely attempting conversation - and definitely not a heated one.
David Duff

Vinny Burgoo said...

Dhogaza: 'Didn't Sagan realize that Columbus was a clown, as well?'

Clown? For thinking the world was pear-shaped? Isn't that the prevailing worldview hereabouts?

Vinny Burgoo said...

Re Part II: Thanks a bunch, MT! It took me at least an hour to work out that you were joking.

(You are joking, aren't you? The pink line does exactly what it says on the tin.)

Re Part I: I am flattered to be included in such company but I don't know which points I am supposed to have conceded and then ignored.

EliRabett said...

Denialism is reduced to throwing spaghetti against the wall and hoping that something sticks which leads to claiming that every one of a set of mutually contradictory papers are just wonderful.

Anna Haynes said...

> "They are polite, considerate, and show every sign of seeing your point. Then they proceed to ignore it or forget it had been made."

My guess du jour is that this is neurological: old dog, new tricks.

There was a wonderful writeup (that I'd love to be able to find again) about Mr. Television Engineer of the ~1950s talking to Mr. Backward, who'd been convinced there was a man inside the TV that made it talk; Mr Engineer patiently explains and explains, finally Mr. Backward says "ok, I see...
...but couldn't there be just a *little* man in there?"

It's hard to remodel sclerotic pigeonholes.

Reflective listening might be a good thing to ask of them; to phrase the right answer with their own brains&fingers, right then when you've explained it, might help to engrave it in their minds.

Anna Haynes said...

Is Aspergers correlated with reduced self-knowledge? (i.e. a heightened susceptibility to DKE)

And have others noticed a correlation between it and climate contrarianism?
(my sample size is way too small to be meaningful, but my gut is convinced nonetheless)

silburnl said...

@Vinny "Clown? For thinking the world was pear-shaped? Isn't that the prevailing worldview hereabouts?"

No. He was a clown for getting the circumference of the world (wildly) wrong. Which is what Dhog said in the very next 'graph of his post if you'd bothered to read on...

CC never did accept that he was wrong about his circumference estimate BTW. He went to his grave saying that Asia was just a little further on from the islands he had discovered.

An example of scientific progress happening 'one funeral at a time' perhaps.

Regards
Luke

Martin said...

That is why weather forecasts are never much good after 3 to 5 days and why attempts to forecast climate in 30 to 50 years are doomed to failure.

So you didn't understand it either.

Vinny Burgoo said...

@Luke: 'No. He was a clown for getting the circumference of the world (wildly) wrong.'

It's only wildly wrong to those who don't think the world is pear-shaped - that is, with a northern temperate circumference about half that found in the southern demipirum. Which is what poor old Cristobal thought.

Michael Tobis said...

Vinny: "You are joking, aren't you? The pink line does exactly what it says on the tin."

Well, so does the IPCC millenial graph. So I presume you have no objection to any graph provided the fine print is accurate?

I think the pink line is useful information about the physics of the system but does not belong among the scenario pictures in the Summary for Policy Makers. There it can easily be read to support the common misimpression that we can start worrying about climate change once it gets serious.

It in fact understates the lurking "hidden warming" that we will have to contend with once we get serious. If the now apparent changes are the consequence of our behavior until 1985 that has very different import than if what we see is pretty much everything we are committed to.

The pink line is as described, but it doesn't belong among the SPM scenarios, because it isn't a realistic scenario. At least, it is misleading in the same way that the "hide the decline" is misleading, though with the opposite import. You can't just complain about one and shrug off the other as suits your own biases about what IPCC does and why.

Carrick said...

Tobis: "The fourth kind is the tantalizing sort like Lucia herself or "Carrick" or (I'm still not sure about this) "Vinny Burgoo". They are polite, considerate, and show every sign of seeing your point. Then they proceed to ignore it or forget it had been made."

Nice snarky comment there, but how about giving an example where I either ignored a point that I conceded or where I forgot a point after conceding it?

I don't think you are very honest.

Michael Tobis said...

Actually, perhaps a bit sloppy.

Original text amended. I put you in the "unsure" category as well.

Vinny Burgoo said...

MT: 'It in fact understates the lurking "hidden warming" that we will have to contend with once we get serious.'

Perhaps the pink line was included in the SPM because it makes the problem look more manageable - don't want to scare the horses into thinking 'What's the point?'

I googled upon a 2005 dissertation the other day that proposed using what the author called a 'geophysical commitment' rather than the pink line's 'constant composition commitment' as a baseline. Did that notion ever gain acceptance anywhere?

Here it is:

http://www.up.ethz.ch/publications/documents/Meinshausen_2005_dissertation.pdf
(5.4 MB)

Of course, you'd need small-print to explain why warming goes nuts for a few years after Year Zero. But that's OK.

(Sorry. If this is a duplicate. Connection playing up.)

Michael Tobis said...

Well, OK, so IPCC skews data to make the problem look more manageable AND to look make the problem look more scary. Hmmm....

Vinny Burgoo said...

It's an international tranzi push-me-pull-you behemoth, innit.

Zeke said...

MT: The figure on SO2 emissions by SRES scenario that you link is from Chapter 3 of the AR4. My article discussing it can be found here: http://www.yaleclimatemediaforum.org/2008/06/common-climate-misconceptions-why-reducing-sulfate-aerosol-emissions-complicates-efforts-to-moderate-climate-change/

Horatio Algeranon said...

Good points and nicely developed.

Inspired Horatio to write a ditty on Incoherence

Come to think of it, nearly every one of Horatio's ditties (sp?) highlights incoherence (or is incoherent, some might say)

Carrick said...

Michael Tobis: "Original text amended. I put you in the "unsure" category as well."

To set the record straight, I accept the general physical basis for climate change, which is a different thing that thinking we have it nailed.

In general, I accept the standard climate sensitivity, and believe that the global mean instrumental surface temperature reconstructions are reliable. I do think there are errors on the regional scale that need to be addressed, and would like to see more complete instrumentation coverage of the globe, but I don't think any of these wishes, if carried out, will have any meaningful effect on policy.

I generally accepted the body of AR4 WG1, with some qualifications (a few of those were addressed in the thread on Lucia's blog you referenced, and contrary to what you originally stated about me, your replies to my comments were food for thought for me, I neither "forgot" nor "reset" my argument after that exchange).

That said,I think AR4 WG2 has some serious lapses in scholarship and it needs a complete "redo" to that point that I am rather pissed at the group leaders for what I view as sloppy worksmanship. At the moment, I am "unsure" about the climate impact issues, I am hoping that AR5 will follow a much more rigorous and much less "touchy-feely" approach.

My own interest for haunting the climate blogs is to examine how climate data is analyzed and to look for overlaps between that and my own research. This is a very different goal than trying to sway other people's opinion about policy issues. If for example I study the UHI effect, it is from the viewpoint of a practitioner, and not somebody trying to score political points on either side of the debate.

If you want to discuss the sociology, there is an interesting range of critters on the strong CAGW supporters side too. I'd encourage you to engage that issue intellectually, because some of them at least make your work of selling this to the public harder, not easier. Most people are not rational in how they fix belief.

Michael Tobis said...

It may be worthy of note in this context that I have never, at least to my recollection, publicly commented on the quality of WG II.

I will say that on many occasions I recall refraining from doing so. This is one such.