320 likes | 399 Views
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.
E N D
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 competition for fresh water may well become a source of conflict & wars in the future.” Kofi Annan, March 2001 260 international basins: +/- tensions: longstanding, always, growing with demand 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.
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.
1.7 x decrease 4.5 x decrease 7.5 x decrease Water Availability Shiklomanov
Economic Impact of Climate Variability Source: World Bank 2005
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
Climate Water Agriculture Energy Health Human Activity Managing Water Resource Systems • Balance Water Supply and Demand • Historical rules for resource allocation • How much, and when should these rules be modified ? • How do we assess and communicate potential impacts of action & inaction ? Well Field Electric Grid Dam 1 Dam 2 Irrigated Farms 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)
Statistical Model Application - Forecasts Historical Inflow Observations Sea Surface Temperatures Photo: MWSS Global Climate Model Cross-Validated Model RAINFALL WINDS 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
relevant variables: eg: reservoir inflowdry spell or flood risk PDF/CDF “prob. of exceedance” * historical * predictive * real-time monitoring Summarizing Climate into Risk Management = tailored probabilistic climate information within a specific institutional and policy setting