Tuesday, July 14, 2015

Climate change: Black Swans?

This morning I was doing some on-line research as a follow-up to yesterday's posting about climate change vulnerabilities. There has been a number of recent reports that begin to frame some of the issues we're facing. For example, the 2013 report Adapting to Climate Change in Minnesota notes "Rivers, lakes and  groundwater  aquifers  currently  used  for  drinking  water  supply  may  be  affected  by  climate   change  through  disruption  of  the  long-­‐term  equilibrium  of  the  hydrologic  cycle." [p 22]

The Minnesota Department of Health has done a Climate Change Vulnerability Assessment. It states: "In Minnesota, climate change will impact flooding principally through changes in precipitation. Precipitation is projected to increase in winter and spring, and to become more intense throughout the year (Karl et al., 2009). This pattern is expected to lead to more frequent flooding, increasing infrastructure damage, and impacts on human health."

Highway 210, Jay Cooke East Park entrance, from Incorporating Extreme Weather Risks in Asset Management Planning
Highway 210, Jay Cooke East Park entrance, from Incorporating Extreme Weather Risks in Asset Management Planning

One of the most basic ways I've learned to approach risk analysis is to consider both the probability of an event and its impact. Probability ranges from 100% to 0% although I'm not sure whether a Black Swan fits within this range. (Here we're talking about the theory by Nassim Nicholas Taleb, not the movie about ballerinas.)
"What we call here a Black Swan (and capitalize it) is an event with the following three attributes.

First, it is an outlier, as it lies outside the realm of regular expectations, because nothing in the past can convincingly point to its possibility. Second, it carries an extreme 'impact'. Third, in spite of its outlier status, human nature makes us concoct explanations for its occurrence after the fact, making it explainable and predictable."
The troublesome phrase for me is "regular expectations." I regularly expect everything to fall within a 0% to 100% probability.(YMMV) So, based on that and the "extreme impact" criteria, here's how I think we can talk about risk analysis, Black Swans and climate change. (Unfortunately, we're also going to have to come close to flirting with Secretary Rumsfeld's "known knowns to unknown unknowns," the latter probably nicely covering many Black Swan events.) Our universe then is divided into quadrants:

High Probability / High Impact     High Probability / Low Impact
Low Probability / High Impact     Low Probability / Low Impact

Using this schema, Black Swans live somewhere in the Low Probability / High Impact quadrant, and we probably don't pay much attention to whatever happens in the Low Probability / Low Impact quadrant.

Highway 2 and 35 near Duluth, from Incorporating Extreme Weather Risks in Asset Management Planning

From what I've been able to see so far, little of Minnesota's assessment of responses to climate change has used a risk management type of approach. Most follow a step-down of one or more national assessments. A welcome exception is work being done by the Minnesota Department of Transportation as part of a Federal Highway Administration pilot study. The effort is "Incorporating Extreme Weather Risks in Asset Management Planning." Minnesota's Flash Flood assessment has these objectives:
  • Better understand the trunk highway network’s risk from flash flooding
  • Identify cost-effect options to improve the network’s resiliency
  • Support the development of Minnesota’s first Transportation Asset Management Plan (TAMP)
  • Provide feedback to FHWA on the Draft Framework
It seems to me that Minnesota will be better served it it starts to use scenario planning and a more structured risk assessment in it's planning for adaptation to climate change. Anthropogenic Climate Disruption seems to be increasing the likelihood of Black Swans landing more than simply planning for a warmer, wetter future will accommodate.

[UPDATE: after this was posted, CLIMATE CHANGE: A RISK ASSESSMENT was noted on Twitter.]

Arroyo: Flash Flood

By John Unterecker 

The canyon walls close in again,
slant light a silver glare in brown water.
The water is only knee deep, but when the boy reaches the
purple dark, silvered by the smash of brute water—
water will tear at his chest and arms.
The walls of the canyon are brilliant in late light.
They would have glared red and gold for his drowned camera:
splashed blood to his left, to his right a wall of sun laddered
   with boulders.
More than boulders.    Some stranger once fought down this
his rope of twisted dry vines strung boulder to boulder,
clifftop to arroyo.    Escape.    Escape maybe.    Maybe bones
   in the desert.
I think of hands scuffed raw from the braiding.
Almost….  Water froths over the boulders,
tugs at the boy’s footing.       Almost….
The blood cliff to his left blinds him.    Blind nails scrape at
    two boulders,
a torn vine whipping somewhere above him.
He wedges knees against polished rock, pressing up, clawing
    slick stone.
Now.    Rope cutting his hand, he skids underwater:
silver and froth, a film of bright blood staining his eyes.
But he drags hand over hand up out of the water, climbing
    the sun
hand over hand, the ancient vines holding,
boulders for foothold, up out of that canyon.

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