ASP Summer Colloquium on Uncertainty in Climate Change Research:

An Integrated Approach

Welcome!

NCAR, Boulder, CO July 21 - August 6, 2014

Introduction to the ASP Summer Colloquium on

Uncertainty in Climate Change Research:An Integrated Approach

Linda O. MearnsNational Center for Atmospheric Research

NCAR, Boulder, CO July 21 - August 6, 2014

“To know one’s ignorance is the best part of knowledge”

–Lao Tzu

“Any clear way, though it lead to death, is preferable to the tangle of uncertainty”.

- Charles Horton Cooley, U.S. sociologist

“Doubt is not a pleasant condition, but certainty is an absurd one.” -Voltaire

Uncertainty – what is it?

A state of lack of knowledge or incomplete knowledge or more completely: A state of incomplete knowledge (about the future), often with a random component reflecting random processes (e.g, rolling of dice). Total uncertainty is a combination of random (aleatory) uncertainty and epistemic uncertainty (the incomplete knowledge due to complexity of world). Probability is viewed as the standard measure of uncertainty.

But first, what do we know?

Data from Climate Monitoring and Diagnostics Lab., NOAA. Data prior to 1974 from C. Keeling, Scripps Inst. Oceanogr.

Changing Atmospheric Composition of CO2

Mauna Loa, Hawaii

Rate increasing

ppm390

380

370

360

350

340

330

320

310 1960 1970 1980 1990 . 2000 2010

K. Trenberth

Entered graduate school

ReceivedPhD

Got CO2

sample

Mauna Loa Observatory

Sealing the Sample

ExtremesHurricane Sandy

Made landfall on New Jersey shore October 29, 2012.

Example of Damage: what’s it got to do

with climate change?• Consolidated Edison electricity substation

in lower Manahttan stopped working at 9 p.m. Monday evening

• Flood protection barrier was overtopped (designed to be 1.5 ft above 10 ft storm surge of record)

• Sandy’s storm surge = 14 ft

R. Henson

IPCC, 2001

The Integration Problem

Cascade of Uncertainty for Climate Change Research

Decision-Making(Assessment of needs, decision entry points,

institutional constraints,politics etc.)

Mitigation

Adaptation

Toward Decision-making as a Central Focus

Scientific Information inDecision Processes

Physical Science

SocietySociety

Society

SocietalIssues

Physical Science

Other Knowledge

SocietalIssues

Other Knowledge

S. Moser

Developing Mitigation and Adaptation Strategies

Moving from ‘Is Climate Change Happening?’ to ‘What do we do about it?’

Emphasis on Actionable Science

Positive Signs of Integration

IPCC WG2 (2014)

Risk Management

• ‘Iterative risk management is a useful framework for decision making in complex situations characterized by large potential consequences, persistent uncertainties, long time frames and multiple climatic and non-climatic influences changing over time.’

» IPCC, 2014 (WG2 SPM)

Why are we doing this Colloquium?

• To understand the strands of uncertainty throughout the climate change problem in order to maximize effectiveness in any one area.

• It does not mean that all participants are expected to always engage in highly interdisciplinary research.

• It does mean that hopefully your research activities will be informed by and benefit from the larger uncertainty context.

The Importance of Generational Change

Stephen H. Schneider 1945 - 2010

The End

S. Schneider, 1978in

Climatic Limits to Growth

‘Tough decisions that have to be made generally are value judgments of how to weigh risks and benefits in the face of large uncertainties.’