This got mentioned in early 2014 at Planet3.0. To be fair to mt, he wasn’t really pushing the video itself, just using it to illustrate his point (which I think is uncertainty-is-not-your-friend; I agree with that), though he did call it “excellent”. But since, as I said in the comments there I don’t think its great video; I think its terrible, I wasn’t desperately happy. But, I shrugged and turned away. Now I see that Dana Nuccitelli is giving it space in the Graun, (and DA is linking to it, though possibly only because he likes the headline and sub), so I’ll repeat myself more publically. What I said, in full, was:
I don’t think its great video; I think its terrible.
Minorly, A / True doesn’t have a happy face – it still has an appalling financial meltdown (in his scenario).
But more importantly, he makes no attempt to assess the probability of B / True. So he’s trying to short-circuit, or evade, the cost-benefit analysis that needs to be done.
That wasn’t the question you asked in this post, of course.
[You need to know that A is “we took action on GW”, B is “we didn’t”. True is “GW turns out to be real”, False is “It was all a dream”.]
mt answers starting with “I think there is a point to what you say”, which is enough for me to excuse him, but not DN. Note that the assertion of the video (see around 1 min in) is that the argument contained therein means “we don’t need to know whether its true or not”.
Note that there’s a a trick: in A / Yes, he takes the extreme, for illustration, and gets global economic meltdown. In B / False, he says “since we granted the extreme in A / Yes, we should grant the extreme here too”. But they aren’t connected, except in both being very simplistic.
At 5:15 he asserts that if you add in the subtleties and intermediate cases, his conclusion (to come) still holds.
And that conclusion is that B / True (“GW is real and we took no action”) is so bad, that the best thing to do is avoid any possibility of “being in that column”. My answer to that is above. At P3, Walter Manny said Craven’s exercise is simply Pascal’s Wager and I don’t think he got a good answer.
To make the comparison clearer, I’ve scribbled on a still from the video. Wittily, that makes GW “God”. We can see its not quite Pascal’s wager. Conventionally, in PW, you assign a small positive to “no God, and no Belief” and a small negative to “no God, Belief” to reflect the life of sin that good Christians can’t enjoy; in this case, “no GW, Belief-aka-action” has substantial costs, but they are assumed small compared to the “Hell” square. Similarly, in PW the “God, Belief” square is infinitely positive, whereas here its actually worse than “no God, no belief” which is the best possible outcome, though we’re not supposed to believe in it. Indeed the comparison to PW is only that “God-aka-GW, no-belief-aka-no-action” is effectively infinitely bad in both.
The useful point about comparing it to PW, though, is that no-one believes in God because of it. So if the comparison is good (I think it is) you can assert “no-one will believe in action on GW just because of this grid”.
The good atheist assigns zero probability to “God exists”, and so zero probability to Hell, so that part becomes irrelevant in the calculations. The experienced denialist assigns zero probability to “GW will be catastrophic”, and so ignores that bit. I’m not an experienced denialist, so I’m not ignoring it, but I am downplaying it. Why? Mostly because i think we want to do something more sensible, which is to attempt a reason-based cost-benefit type analysis, which this isn’t. If forced to go further, I’d say that current best-guess is that GW won’t be an utter catastrophe; indeed, in economic terms (say, those of Stern which I think is on the high side) its perhaps (from memory) 10-20% of global GDP by 2100. To make it catastrophic – somewhere close to the infinity that is implied – you need to try much harder than Stern, and I think that’s unlikely (I also think that if starting looking that way, we’d probably have time to go into emergency mode (yes, despite the inertia of the pol/econ system, and our infrastructure base); a time-dependent element is necessary in the analysis, but lacking here. He makes a small comment in this direction at 7:20 – that we’ve recently learnt that the disaster could happen quickly, within a decade, so it affects us not our grandchildren; I don’t know what he means by that).
In case you’re wondering, no, I’m not arguing that the failure of the argument in the video means we should do nothing about GW. I’m only arguing that the failure of the argument in the video means it should have no (logical) consequences.
To paraphrase Einstein, you should reduce a problem to the simplest possible, but no simpler. This square reduces the problem past the minimum degree of simplicity that is useful.
As I said near the start, mt’s main argument around this point is uncertainty-is-not-your-friend; and I agree with that. There’s an essentially-sane take on that at The Conversation: Uncertainty isn’t cause for climate complacency – quite the opposite. But then again, it doesn’t reach the same conclusions as Greg Craven.
Good grief, you’re behind the times
It turns out that the video dates from 2007, duh. And Greg Craven wrote a book about the same idea in 2009. Which I haven’t read, but judging from reviews (treehugger, Simon Singh, Grist) it says much the same as the video. mt has a review at P3 that focusses on a completely different aspect of the book – how to know, to which the answer for most people is “trust”, which is correct, though its important to know how to know who to trust. But at that time, he doesn’t address what I (and the other reviewers) are taking as the book’s central argument.
There’s a wiki page. He even had a website about it, now apparently defunct. But via the wayback machine I can read http://www.gregcraven.org/en/the-book/endorsements-and-criticisms which points me at a response by “climate skeptic” (the wiki page used to ref this, but it got rm’d as non-RS).
I rally can’t endorse “climate skeptic” in general, because he links with approval to himself at coyote blog to show that feedbacks are probably negative, which says nothing useful but points to himself again. At that points he actually starts to say things, but they’re wrong (in a traditional-septic-but-not-actually-barking way, so I’ll spare you the details). And now I read it, I can’t really endorse his crit of the video, either, except in very general terms.
* Things I thought were obvious! – ATTP
* Is Climate Risk Systematically Understated? – asks mt at P3. Likely, yes.
* Taxonomy of climate/energy policy perspectives – essentially a rip-off of the same thing; from Curry