Monday, August 17, 2009

Why Environmentalists Can't Convince Skeptics

Consider a mother talking to her kid about risk.

Whether the topic is crossing the street, talking to strangers, using the stove, driving a car, setting off fireworks, or balancing near a cliff, mom is likely to overstate the risks at least a little bit. "Ask a mom and you get a worst-case scenario." Mom is attuned to the downside; she knows what the worst possibility is and over-weights its likelihood. If you cross the street alone, she knows you'll get hit by a car. If you talk to a stranger you'll get kidnapped. And she doesn't just overweight the risks; she also under-weights the benefits - how much fun you are likely to have doing the forbidden thing, whatever it might be. And she doesn't trust her kid to judge the risks for himself.

So mom exaggerates. But the kid *knows* that mom is a worrywart, so the kid automatically discounts everything mom says. If mom says something is risky there's probably *some* risk there, but it's sensible to figure it's being overestimated by at least an order of magnitude. So you can pay a little attention to mom's worries, but not too much - you don't want to take her too seriously. And mom *knows* the kid is discounting what she says and not paying close attention, which gives mom *even more* incentive to exaggerate, which gives the kid *even more* incentive to discount.

This is a stable equilibrium. Once started, the dynamic is nearly impossible to break because it would require both parties to change at the same time.

Conversations between environmentalists and enviroskeptics have that exact dynamic. Environmentalists are "mom". They "have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts", to quote Stephen Schneider. They do this partly because that's what gets publicity and funding, but they also do it because if they accurately portrayed their certainty level it would give "the other side" a reason to ignore them. So they exaggerate a bit. They also tilt the playing field in various ways. They avoid public debates, they share data and methods only with fellow travelers to the extent they can get away with this, they try to avoid even mentioning anybody on "the other side".

The skeptics know this is happening, so they discount the claims they hear made by environmentalists. The environmentalists know their claims are being discounted, so they find every excuse to build them up even more.

A stable equilibrium.


At 7:49 AM, Blogger Hank Roberts said...

I looked at your site after seeing an innumerate post, utterly wrong about significance levels and risk.

And here, I find the same old misleading use of that fragmentary quote, a few words taken out of context.

Searching for those same few words out of context is one of the most effective ways to locate the broad spectrum of what Connolley calls septic bloggers. Bad company you're in there.

The approach wins public opinion:

At 8:18 AM, Blogger Glen said...

Hank, I know you believe that quote is much better in context, but it's not. The terse version I used is part of the takeaway most people get from the longer version if they weren't already inclined to sympathize with Schneider.

I don't know what happened to the link, though. I intended the Schneider link in my post to take people to somewhere they could find the full quote. I'll fix that, thanks.

At 8:26 AM, Blogger Glen said...

What I posted to RC was the simplest, least sophisticated version possible of a larger argument I'd like to make on the subject, but I didn't want to say too much in an RC comment due to (a) their editing policies - I couldn't presume an opportunity to rebut if I got snipped, and (b) it was off topic.

I'll make a main post here about that soon; maybe we can discuss it then.

At 8:27 AM, Blogger Hank Roberts said...

Ah, your innumerate post has a reply from someone who knows much more than I about statistics:

At 3:21 PM, Blogger Glen said...

Martin's post makes it clear I left too much ambiguity about what the exact proposition is that we're assigning probabilities to.

I don't doubt the planet has warmed over the last century or that human activity (including but not limited to CO2 production) is a contributing factor to measured warming. For me what remains to be proven is that the amount of warming attributable to human activity is *such* a bad, scary, dangerous thing that we need to ACT NOW to stop it, as opposed to waiting a bit longer to see if our predictions are right about how much it's going to warm or how bad it will be that it does.

I suspect CO2 is more a positive than a negative externality, at least for the next few decades. I don't think it's been proven "at the 95% significance level" that CO2-caused warming is on-net negative for humanity as a whole even over, say, the next 50 years, much less *so* negative as to justify inflicting serious economic costs on the world today. Looking past that to the next century or so, the prospect of continued economic/technological progress makes me loathe to predict we won't be vastly better at terraforming to fix whatever problems we see crop up in the future than we are today...if they turn out to be problems.

What's the rush?

Martin says "what we don’t know, with any great precision, is how big it is". That's what I want to know, more or less. I want to be pretty certain the costs are high enough that our best option isn't to wait. Until we have that certainty, I'm willing to wait for more data to be collected.


Post a Comment

<< Home