2010-11-11 17:02:30The next meme du jour - uncertainty
John Cook

john@skepticalscience...
124.186.160.198

I'm seeing the topic of uncertainty come up more and more often lately. We do have a skeptic argument "There's too much uncertainty" that needs rebutting (perhaps can be worded to be more specific such as "We shouldn't act until we have more certainty"). So if anyone wants to tackle this one, feel free to claim it.

It will certainly get bandied around big time next week. Judith Curry is testifying to U.S. Congress on Nov 17 - the climategate birthday, if you will - to discuss "discuss how we can go about responding to the climate change issue in the face of uncertainty, dissent and disagreement":

http://judithcurry.com/2010/11/10/uncertainty-gets-a-seat-at-the-%E2%80%9Cbig-table%E2%80%9D/

2010-11-11 17:46:21Some good thoughts on uncertainty (just collecting various bits and pieces at the moment)
John Cook

john@skepticalscience...
124.186.160.198

Garnaut: what if mainstream science is right?

And yet in some of the Australian public discussion, it has been common to assert that the presence of uncertainty makes it appropriate to adopt weaker approaches to mitigation. This error has been made by economists, who honestly and disarmingly say that they are not scientists, but that there is uncertainty, which means that we should not do as much as if we were certain about the outcome (Carmody, 2010).

This view is based on a misreading of the scientific discussion of uncertainty. It is good for non-scientists to recognise their limitations. I hope that I always do so. But this whole field of concern begins with the science, and it is encumbent on economists entering the public policy debate at least to inform themselves on what the scientists are saying.

Reading the scientific literature, taking into account the range of opinions on various matters, and the Royal Society’s recent paper on uncertainty about climate science, the informed non-scientist is left in little doubt about the way in which the scientific community sees uncertainty in climate change. Uncertainty relates to the dispersion in the probability distribution around mean or median outcomes, and not about whether there is any impact at all. (Disconcertingly for an economist brought up on the probability theory of Keynes (1921) and Knight (1921), the science literature tends to use the word “uncertainty” to cover as well what I would think of as “risk”). The focus is on mean or median outcomes.

Actual outcomes may turn out to be more benign or more severe than the mean. The advance of knowledge may change the mean or median, or make the dispersion of the probability distribution around the mean larger or smaller. Only a smaller dispersion of the probability distribution would be regarded as a reduction in risk or uncertainty.


 

2010-11-12 03:52:42Curry
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252
We can thank Curry for the 'uncertainty' meme becoming more popular amongst 'skeptics'.  A number of bloggers have addressed the failings in Curry's "Italian Flag" uncertainty nonsense.  James Annan here  and here and Michael Tobis here.
2010-11-13 03:37:54
MarkR
Mark Richardson
m.t.richardson2@gmail...
192.171.166.144

I likehow we got Ambaum to do a post... I was in one of his Atmospheric Physics problems classes this morning!

He never gives the answers. 

2010-11-13 03:57:27good guest post
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.252
Cool stuff Mark.  Yeah, that was an interesting guest post.
2010-11-13 21:54:02How Ambaum came to write a guest post
John Cook

john@skepticalscience...
124.187.70.220
I noticed he'd posted a comment linking to his new paper. That piqued my curiosity so I googles the paper. What came up was a skeptic blog citing his paper to discredit climate science. What really interested me was Ambaum posted a comment on that blog, contradicting the skeptic's conclusions. So I emailed him, offering the opportunity to write a guest post setting the record straight - the blog post could also serve as a handy resource to link to if other skeptic blogs misused his paper. I was very happy when he agreed to write a guest post.

(okay, i admit it. I'm a science geek, I always get excited when scientists get involved at SkS)