Transcript B04_MacNeill_NSGC workshop

Understanding and Communicating
Scientific Uncertainty
Dave MacNeill, Great Lakes Fisheries Specialist
NY Sea Grant Extension, SUNY Oswego
[email protected]
Apocalypse
Climate models
Decision-making
Those nagging questions
Convincing
evidence
+
Contentious
points
Is climate
change real?
Climate change is multifaceted….
• defining issue for the future of mankind.
• research and outreach priority.
• necessitates integrative approach for
communication, problem solving and
decision-making.
• science model.
My favorite perspective on uncertainty:
“As we know, there are known knowns.
There are things we know we know.
We also know there are known unknowns.
That is to say we know there are some
things we do not know.
But there are also unknown unknowns,
the ones we don't know we don't know.”
— Donald Rumsfeldt,
Feb. 12, 2002,
Department of
Defense news briefing
Understanding the concepts of risk and
uncertainty with a deck of cards??
The uncertainty: What
poker hand will I draw next?
The Dead Man’s Hand:
unlucky for Wild Bill Hickok?
The risk: What is the probability
of drawing this hand? (<1%)
But, the card deck changes unexpectedly……
Death
cards
Other
cards
The Risk ?
Cascading Uncertainties in Climate Science
Adapted from Schneider 1983
Emission
scenarios
Carbon cycle
response
Global
climate
sensitivity
Regional
climate change
scenarios
Range of
possible
impacts
Mac’s Uncertainty Concept Model
Stochastic
(Surprises)
Nature
Epistemic
(Unknowns)
Scientists
Science
Knowledge
Knowledge
communication
(translation)
Non-Scientists
Human reflexive
(volition)
Decisions
“You just don’t understand because our work is
too complicated. We know what is best because
science provides the best information for solving
problems, but it is not our job to explain it to
you”. We’re scientists, not interpreters”.
“You don’t understand it either, because
science is sloppy and a collection of useless
facts. We have our own ideas that make
perfect sense to us. You’re arrogant, out-of
touch and have impractical ideas”.
“Our models and statistics predict that change is
occurring and we need to take action to reduce
risks.”
“Prove it, your models and statistics have
been wrong before and it makes no sense to
take any action to prevent something that
you can’t prove”.
Scientist
A
n
e
x
a
g
g
e
Non-scientist
Uncertainty
r
a
t
e
d
v
i
e
w
Science: God-like, Evil or Golem?
•
•
•
•
•
Mythical, unapproachable crusader
Ultimate source of knowledge/wisdom
Operates in unencumbered, controlled environment
Strives for perfection
Accountable, held to high standard
•
•
•
Misanthropic (justification), self-serving
Seeks power, fame and fortune
Unbridled, dangerous, rogue element
Truth
•
•
•
•
•
Increasingly powerful, a creature of our own design.
Neither good or bad, protective, follows orders
Clumsy/dangerous, must be controlled
Fallible = low expectations,
Can’t be blamed for mistakes if it is trying
Science
Stochastic
(Surprises)
Nature
Epistemic
(Unknowns)
Scientists
Science
Knowledge
Knowledge
communication
(translation)
Non-Scientists
Human reflexive
(volition)
Decisions
The Climate Uncertainty “Toolbox”
Communicating Uncertainty:
Examples from Weather Forecasts
• Numerical probabilities:
– A 30 % chance of rain.
• Qualitative or categorical forecasts:
– Today’s weather will be “fine”.
Handmer et al. 2007
An Interesting Expert Opinion:
An Essay: Divergent American Reactions to Terrorism and Climate Change
Cass Sustein 2007: Columbia Law Review 107: 503-557
“We have to deal with this new type of threat [terrorism] in a
new way we haven’t yet defined.. With a low-probability, high
impact event like this.. if there is a 1% chance that Pakistani
nuclear scientists are helping Al Qaeda build or develop a
nuclear weapon, we have to treat it as a certainty in terms of
our response”
-- Dick Cheney, Former Vice-President
“Climate change is the most severe problem we are facing
today - more serious than the threat from terrorism”
– Sir David King Director, Smith School of Environment, Oxford; Research Director,
Dept. of Physical Chemistry, Cambridge; Former Chief Scientific Advisor to Blair
Administration.
Climate Change – Global Warming Scenarios
And now, the punch line(s)……
• Climate change uncertainties: research and outreach challenges
• Uncertainties are cumulative: science to policy
• Integrative natural and social science approach to decisionmaking.
• Scenarios: address insurmountable uncertainties.
• Outreach:
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–
–
–
–
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sources of uncertainty
science mechanics
restore faith in science
assess/understand heuristics
facilitate improved decision-making
craft a responsible, informative and useful message
Epilogue
“Any philosophy that in its quest for
certainty ignores the reality of the
uncertain in the ongoing processes
of nature, denies the conditions out
of which it arises.”
John Dewey, The Quest for Certainty, 1929