Let's Audit Alex Epstein

Or so proposes Bryan Caplan1. Happily, Waterstones has a copy of Fossil Future, and I browsed far enough to get past the vague wurble into real things that were potentially erroneous, and stopped. Here are two, since that's what BC wanted.

Hansen's predictions

hansen-so-they-say Here we see a graph of "Hansen's predictions" versus reality. Pretty shitty, huh? Case closed. Or... is it?

Those who swim in these things will recall Gavin's nice RealClimate posts discussing Hansen's predictions, and they look somewhat different. I've inlined it too, to save you the terrible effort of clicking on a link.

They aren't on the same time axis (I'm not sure why AE wants to go back to 1880) but they both cover the relevant period, 1960 onwards.

To understand which of the models runs (scenario A, B or C) you should compare to the obs is somewhat complex; Gavin does a good job of going through it; the answer is not-A, but (simplifying) somewhere between B and C. Naturally, he doesn't just pull this out of thin air, he goes through the assumptions and the numbers.

So how to reconcile that with what AE produces? Clearly, AE hasn't used Hansen's actual scenarios, because he shows two piece-wise linears. Indeed, he isn't using Hansen '88, he's using a New York Times story from 1986. Which is based (possibly loosely) on Hansen's testimony from 1986. Which after some effort I can find. It features (see the written testimony p 78) two scenarios, A and B, which I didn't examine in detail so I don't know if they're the same as 1988's version; but A is as in 1988 higher forcing (and from the testimony, and from figure 8 which appears to show B only extending to 1990, I think A was taken more seriously. I should also throw in the caveats that Hansen did, including that CS is uncertain - in his results - by a factor of at least 2). Looking at figure 8 (ha ha, you'll have to go open it yourselves) I'd say the delta-T from 1986 to 2010 in scenario A is about 0.8 oC, so I don't know where the NYT, and thus AE, have got their stonking 5 oF (note: oF) from.

Conclusion: using a newspaper report for a scientists work, when their testimony is available, is slovenly; we all know - or we all should know - that the media are not to be relied on for accurate reporting. Further, using exclusively the 1986 testimony rather than the much better know and analysed 1988 testimony is at best a puzzling choice, and should be justified, which AE fails to do.

Can you trust the SPM?

AE avers
One way to catch major distortions of synthesized research by disseming toes is to review, even briefly, the synthesis that they are claiming to report on

If you do this with the actual IPCC synthesis reports, you will likely be shocked by how badly they are distorted by mainstream dissemination including the IPCC's own disseminator document, the Summary for Policy makers.

The distortions involved in these summaries have been repeatedly documented by researchers who have resigned from IPCC dissemination bodies such as leading climate economist Richard Tol. Tol resigned from ammary group, protesting that "The IPCC shifted from... 'Not without risk but manageable, to 'We're all gonna die" - "from what I think is a relatively accurate assessment of recent developments in literature to...the Four Horsemen of the Apocalypse."
While I am happy to agree that those discoursing on the IPCC reports frequently distort their content, I'm unaware of any use of "we're all gonna die" anywhere in any of the SPMs, whatever Tol may say (if you want to read him talking about Horsemen, see here). And AE doesn't actually provide any example of anything the SPMs distort; I'm doubtful that they do. Also, Tol resigned from WG2, not from the Synthesis report (IPCC produces WG1, 2 and 3 reports; and a Synthesis report; and Technical Summaries (not for the Syn) and Summaries for Policymakers (SPM) of them all.

This is important for AE, because he knows you aren't going to read the full IPCC reports, let alone the papers behind them. You (or at least the Important Busy Folk) are going to read the SPM. AE doesn't want to look like a rabid denialist, so he settles for trying to discredit the summaries.

Conclusion: if AE thinks any of the SPMs have shockingly distorted the reports they summarise, he really needs to spend some time documenting it; I doubt that it is true.


1. Regular readers will be forgiven for wondering "why on Earth would anyone bother to do that"? But I may wish to use this post before a shall-we-say "neutral" audience, so I omit the usual flings2. And no Epstein jokes.

2. You might even want to read through that link, since it is relevant to the general problem of expertise.


Cain's Jawbone

* "Billion Dollar Disasters" are a National Embarrassment: You won't find a more obvious example of bad science from the U.S. government - RP Jr via RS.

* From BC, Dan Klein: In 1893, in the Quarterly Journal of Economics, the classical liberal Simon Newcomb explained that students need to be taught liberal precepts, to see the limits of such precepts, and yet see that such limits must not lead us to throw the baby out with the bathwater: It is not claimed that such propositions [about the beneficialness of liberalization] should be taught dogmatically, as if they were theorems of geometry.  Not only should their limitations be pointed out, when necessary, but the student should be encouraged to find or even to imagine conditions under which the maxims would fail. In doing this, the vice he should be taught to avoid is that of concluding that because he can imagine a state of things under which a maxim would fail, therefore it is worthless.

* Alex Epstein’s *Fossil Future* by  Tyler Cowen

Book Review: Fossil Future by Roger Pielke


PaulS said...

Epstein uses the NYT article where it says temperatures over 1990-2000 are projected to increase by 0.5 - 1F and 2 - 4 F in the following decade.

Epstein starts at 1990 obs, then makes lines of +0.5 and +1 to 2000, then +2 and +4 to 2010.

Trouble is the NYT article is confused about Hansen's testimony in a number of respects. Firstly Hansen's testimony reports anomalies from 1958, not decadal trend magnitudes, and these figures concern US land temperature, not global average. The 2 - 4 range is actually reported for 2010-2020, not the following decade after 1990-2000.

The 0.5 - 1 figure should be centigrade, not Fahrenheit. That error might not be the journalist's fault. You can see in the testimony that the C has been penned, not printed, so may have been a later correction.

William M. Connolley said...

It's all a bit confused. I think using 1986 is just a bad idea.

Over at the Caplan site, a_baby points out that this error has already been picked up and AE has acknowledged it, in my view weakly.

Over in that thread we see AE claiming I take extreme measures to catch errors before I write/say things publicly which I think risible; in this case he has clearly not taken "extreme measures" but has rather been extremely slack.

Anteros said...

I can't disagree that AE is at fault for his Hansen stuff. Everybody who does that same thing comes off looking bad so I wonder why anybody bothers. Also, even if JH was quite a way off with his predictions, so what?
Anyway.. I was thinking in response that given the little niche that AE has - the world's most fanatical fossil fuel advocate - it would be a surprise if he didn't make some slightly dubious claims. And some people should be held to a vastly higher standard - NOAA for instance. I was going to say have you read RPJ's latest post about the 'Billion Dollar Disaster' meme and lo and behold, you put it in your refs. Well done you... I thought it one of Pielke's better pieces, and he makes an excellent case.