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Background & Motivation:
What does Climate have to offer?
Water and CRM Technical Workshop and Training
Addis Ababa, June 30 – July 2, 2009
Credits: IRI, Upmanu Lall, Casey Brown, Dave Watkins
“Fierce
for fresh
water+/maytensions:
well become
260competition
international
basins:
a source of conflict
in the
future.”
longstanding,
always,& wars
growing
with
demand
Kofi Annan, March 2001
Source: Grey & Sadoff, World Bank
Semi-Arid and Arid Sub-Tropics and Tropics & Areas w/
High Population Density
In the 20th century the world population
tripled – while water use multiplied six-fold!
By 2025 two thirds of the people in the world are
expected to live in areas of water shortage or stress.
Source: Vorosmarty et al 2000
Climate change or
just people?
Source: Vorosmarty et al 2000
 Pop +  Consumption=  Demand
54% of annual available fresh water is currently
being used world-wide
•
• Assuming
current consumption, 70% will be used
due to population growth alone by 2025.
For developed country per capita consumption 90%
will be used by 2025.
•
Water Availability
1.7 x decrease
4.5 x decrease
7.5 x decrease
Shiklomanov
Annual Variability of Rainfall
Economic Impact of Climate Variability
Ethiopia: Rainfall, GDP and Agric. GDP
80
25
20
60
40
10
20
5
0
rainfall variation around the mean
-80
GDP growth
Ag GDP growth
year
World Bank
Source: World Bank 2005
2000
-5
-10
-15
-40
-60
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
-20
1983
0
1982
percentage
15
-20
-25
-30
Development Trajectories in River Basins
Development
Utilization
Allocation
The Message
An imminent freshwater crisis
• Demand > Supply
• Access to safe drinking water: currently poor
• High variability in supply  Major investments needed
for growth
• Potential for trans-boundary conflict
• Climate Change: Cause or Effect? Water is the major
uncertainty
The Challenge
• Social and institutional factors often
dictate resource management
strategies
• Climate is a major determinant of risk
• As understanding of climate
improves, how can we adapt traditional
management strategies to use this new
information to reduce societal risk and
improve system resilience ?
• How do we balance the needs of a
local resource manager with products
that convey large scale, technical and
yet uncertain information ?
• How do we judge failure or success ?
The Motivation
• Adaptation to climate change for water resources will require a
change from a business as usual approach
• The climate is no longer stationary with increasing climate
variability and changing normals
• The temporal structure to variability is not static
• Risk varies  different needs
• New climate science is needed for water resource managers
Managing Water Resource Systems
• Balance Water Supply and Demand
• Historical rules for resource
allocation
Climate
Water
• How much, and when should these
rules be modified ?
Agriculture
Energy
Health
• How do we assess and communicate
potential impacts of action & inaction ?
Human Activity
Dam 1
Electric Grid
Dam 2
Irrigated
Farms
Well Field
Irrigated
Farms
Dam 3
New City
Muddy River
The Question
What can Water Resource Managers do?
Climate Risk Management (CRM)
Climate Risk Management
One definition: “CRM focuses on pressing issues of here and now
while factoring in projected changes” (WB)
Protecting against climate hazards so climate opportunities can be
utilized
Methodology to increase decision-making as a major pathway to
adaptation for climate change by leveraging climate science
Key Issues
How should climate change be addressed?
• It’s an open research question
• Much can be gained by learning from those actively engaging
the concept of nonstationarity of climate in practice. Case
studies a key start.
Recommend a technical assessment with weaknesses exposed.
• Understanding of climate impacts on water systems is the
starting point
• Historical data remains the most important source of climate
information for any water system
• Solutions/adaptations should be identified, evaluated and
implemented via IWRM approach
Integrating Management of Climate Risks
An operational definition:
1. Identify hazards associated with climate risks (of all time
scales) to the water system
2. Characterize the climate risks
3. Propose/Assess portfolio of solutions/adaptations to key climate
(and other) risks
Integrating Management of Climate Risks
1. Identify hazards associated with climate risk to
the water system
• What are the key climate challenges that the system faces
now (e.g., frequent drought, flood events, variable flows)
• What damages occur as functions of these events?
• Where are the impacts felt? Are there distributional effects? Is
the environment considered/protected?
• Are there opportunity losses due to risk aversion associated
with current climate risks?
Integrating Management of Climate Risks
2. Characterize hydroclimatic risk
• What are the probabilities, recurrence periods, etc. of hazard
causing events
• Is there spatial or temporal structure?
• Are there probable/predictable changes expected?
• What are the most plausible future scenarios and the
uncertainty associated with them?
• How do these risks compare to the social, economic,
demographic and environmental challenges the water system
faces (severity, uncertainty)?
Integrating Management of Climate Risks
3. Propose/Assess portfolio of solutions/adaptations to
Climate Risks
• Incorporate uncertainty of climate futures in the decision
process
• May favor flexibility over structure (soft vs hard approaches)
• Solutions have spatial and temporal characteristics that
modulate appropriateness based on the climate risks
• Risk solutions are dependent on timeframe of analysis:
- Operational – fixed infrastructure, certain sunk costs
- Planning – infrastructure and other system decisions
Application
Move from Static to Dynamic Risk Management
• Changing climate
• Changing goals
• Changing population demographics and landscape
“Hard” and “Soft” Technologies
• Design & Operation of Structures
• Allocation Rules and Water Rights
• Risk Sharing and Reduction Strategies
Develop ideas through examples at multiple scales
Application
Design flexible, adaptable systems – reliability no longer assured
Suite of options:
• Infrastructure: important, but effective range likely exceeded
• Economic instruments: water banks, options, contracts
• Seasonal forecasts
• Flexible operating rules
• Insurance
• Characterize uncertainties / probabilities
Redundancy in the system
Continuous system performance
Good results payoff in long run
Application
Can we leverage applications of climate science to reduce
(exploit) negative (positive) impacts of climate variability?
Application - Forecasts
Reservoirs operated without forecasts in risk averse mode
• Anticipating drought of record in every year
• Water is kept in the reservoir as a reserve for a drought, instead of being
delivered to irrigators or being used for hydroelectricity production
Forecasts provide enhanced estimate of drought risk
• Identifying opportunities in years when drought risk is low (eg La Niña)
Source: C. Brown (IRI)
Application - Forecasts
Historical Inflow Observations
Sea Surface Temperatures
Photo: MWSS
Global Climate Model
Cross-Validated Model
RAINFALL
WINDS
Statistical
Model
Forecast Inflow for OND 2002
Source: B. Lyon
Application - Forecasts
Probability of exceeding a seasonal rainfall threshold
Choose parameter,
quantity (i.e., number of
dry spells of 7 or more
days), and statistic of
interest (i.e. probability of
exceedance)
Application - Health
Suitability for Malaria Transmission
Application - Agriculture
Index Insurance for Crops
Bridging Climate into Risk Management
Summarizing Climate into Risk Management
PDF/CDF
“prob. of exceedance”
relevant variables:
eg: reservoir inflow
dry spell or flood risk
* historical
* predictive
* real-time monitoring
= tailored probabilistic climate information
within a specific institutional and policy setting