uneca climdev-africa climate and water resources in africa: issues and knowledge gaps for cc...
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UNECA ClimDev-Africa
Climate and Water Resources in Africa: Issues and Knowledge
Gaps for CC Adaptation in Africa
Workshop of the Lead Coordinators of the African Group of
Negotiators on Climate Change Addis Ababa, August 13-17, 2012
Seleshi Bekele Awulachew (Ph.D)Senior Water and Climate Specialist
ACPC-UNECA
Climate Change
Meets Policy
UNECA
Outline
This presentation covers:• The global drivers of change and CC
• Africa’s water & CC
• Climate change effects
• Responses and adaptation
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Global Drivers of Change:We are living in a fast changing world
Growth of private sector
Strength of BRICs
E-Comms
Networked science
9 billion people by 2050
Urbanization
Dietary change
Energy crises
Climate change
Food crises
Water scarcity
Collapsing fish stocks
Deforestation, soil erosion and exhaustion
Global food chains disadvantage smallholders
Economies of scale
increasing challenges – increasing opportunities
Pollution
2 Billion by 2050
Financial crisis
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Global Drivers of Change: Knowledge-Scientific Consensus Change
• Global warming is caused by the emission of GHG & their increasing concentration in the atmosphere due to human activities
• Concentration of the major GHG has increased since 1750 – Carbon dioxide (CO2) increased by 32%– Methane (CH4) increased by 150%– Nitrous Oxide (N2O) increased by 17%– The increase in atmospheric CO2:- fossil-
fuel burning and land use change including deforestation
– The increase in CH4 & N2O : - emissions from energy use, livestock, rice agriculture, and landfill.
• The climate system is driven by solar radiation from the Sun
• Phenomena that affect the energy balance of the climate system would ultimately alter the climate
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Prospects under climate change: Scientific Consensus• Earth’s climate results from
interactions of many processes in the components of the climate system: Anthropogenic system (human activities) disturb the balance
• The climate system and hydrological balance change as a result
• Temperature increase in Africa
• Warm atmosphere which absorb more water vapor and an increase in humidity,
• More water moving through the hydrological cycle, more extreme event
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Africa's Water Resources Base
Resources summary– Rainfall = 670 mm/year
providing = 20,100 km3 – IRW = 3,931km3 (20% of
RF) – 13 major river basins– 63 TB, 63% land area, 93%
total surface water, home for 77% of population
– GW is 15% of IRW– 38 major TB aquifers
– Water development & management is critical for resilience and growth
– Transform development & management of water
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Africa’s Water Challenges
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Safe Drinking Water
Adequate Sanitation
Transboundary Basin Cooperation
Safe Drinking Water
Develop Hydropower
Water for Food Security
Meet Growing Water Demand
Enhance Capacity to Meet Challenges
Manage Water Under CC
Managing water under climate change complex problem
Gap exists:
-Data, science base and analytical capacity, investment
- Adequate development => adequately responding to CV and CC
- Policy and institutional instruments eg. in TB management
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Effects of CC on Water Resources in Africa
• Global models agree in predicting warming of surface temperature over this region, the same models disagree on even the sign of the predicted changes in rainfall and hence river flow.
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(Boko et al, 2007).
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Effects of Climate Change on Water Resources in Africa
• When it comes to the future of water availability in Africa, our best answer would remain uncertain for years to come
• Small changes in temperature will see average river flows and water availability increase by 10-40% in some regions, while in others there will be a decrease of 10-30%
• How can we approach the issue of Climate Change in the context of African river basins, given this uncertainty?
10 models show likely decrease of runoff7 shows like increase of runoff
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Effects of CC on Water
• Africa is one of the most vulnerable continents to climate variability and change because of multiple existing stresses and low adaptive capacity.
• Water Disaster Risk is projected to severely compromise agricultural production, including access to food, in many African countries and regions.
• By 2050, between 350 million and 600 million people are projected to experience increased water stress due to climate change
Fig. Africa’s climate zones by Raúl Iván Alfaro-Pelico, 2010
UNECA At a global scale, water disasters are increasing under climate change
The frequency of heavy precipitation events has increased over most land areas.
Effects of Climate: Water and None Water Disasters
14The annual total and cumulative number of natural disaster events recorded globally between 1900 and 2006
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Effects of Climate: Africa’s risks…
Drought Exposure
Flood Exposure WORLD BANKAFRICA
Spatial ServicesHelpdesk
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Impact of climate change – snow melt- Climate change is already heating Africa
• The icecap on Kilimanjaro disappearing
• Reduction of the icecap by ~82% since 1912o It may disappear within 15
yearso Drying out of several
rivers
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Shrinking of Lake Chad
Lake Chad in a 2001 satellite image, with the actual lake in blue, and vegetation on top of the old lake bed in green. Above that, the changes from 1973 to 1997 are shown.
Driven by climate change or land use change?
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Impact of climate change – sea level rise
• > 25 % of Africa’s population lives within 100km of the coast
• 30 percent of Africa’s coastal countries is at risk of inundation
• Impacts of sea level rise: • Reduced productivity of
coastal fisheries; • Migration and health
issues; • negative impacts on
tourism; 18
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Impacts– agriculture and economy
• Climate is already changing and Africa already impacted
• Ethiopia: Extreme variability affecting GDP as agriculture is affected
• Burkina Faso: Variability linked to cereal productivity
• Kenya:30-50% around the mean- drought & flood
Loss in production, infrastructure, and increased poverty
Impact of rainfall variability on GDP and Agricultural GDP growth
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-60
-40
-20
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year
%
-30
-25
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-15
-10
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rainfall variability
GDP growth
Ag GDP growth
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CC Impacts: production, livelihood, settlement
• Impacts on Production System
• Flood Impacts on Shelter with displacement & migration from one area to another
• Drought influence infectious diseases such meningitis,
• Deplete food & cash savings
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• The weak Infrastructures in Africa
• National Security• Impact on the drinkable
water and water sanitation
• River Basin
CC Impacts: production, livelihood, settlement
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UNECA ClimDev-Africa
Climate Change Mitigation and adaptation through better water management
Mitigation is about gases.
Adaptation is mainly about water(See level rise; most disasters such as flood & drought; vector born diseases; agriculture risk ;
energy generation, ………are linked to water)
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Response: Water Related Disaster Risk Management
• Impacts depend on– Climate extremes– Exposure – VulnerabilityNon-extreme event can produce extreme impact
• Extremes, exposure, vulnerability– Affected by anthropogenic CC and variability and developmentDRR and DRM need to address decreasing exposure and vulnerability
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Response: Continuum of data to decision
• Meteorological & hydrological data are basis for knowledge, decision making & actions for water management, agriculture, aviation, transport, risk management, etc
DataObservations, climate models, time series, trends, projections, event frequency, ….
InformationMeasures of vulnerability and risk, impacts, uncertainty and confidence, variations, …
KnowledgeUnderstanding consequences, evaluating responses, informing decision making, …
DecisionStrategic, policy, investment, new research avenues, response frameworks, …
Delivery of scienceSocietal and developmental
needs
Focus
Managing knowledge & stakeholders engagement at local to global level
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Response: Knowledge and capacity building
Significantly improve Africa's modeling and scientific base• The most common method of developing climate scenarios for quantitative impact
assessments is to use results from Global Climate Model (GCM) experiments• Negligible institutions are able to run such models in Africa
GCMs
RCM or LAM(Dynamic DS)
Statistical Models
(statistical DS)
Regression Models
Stochastic WeatherGenerators
Weather Typing or Classification
Impact Models
(HydrologicModels)
Scenarios
Low Resolution High Resolution
~ 300 kmMonth, season, year
1 KmDay, hour, minute
Reduce uncertainty through research and capacity building- Eg Africa’s climate change and water nexus is largely uncertain
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North Amer-ica 153.0
Latin Amer-ica ,156.0
Europe 179.0 Africa 23.0
Asia 402.0
Aus-oce 13.0
Response: sector water resources use efficiency
• Water use about 4% IRW
• Water supply– 64% • Agriculture about 185M
ha; 7% irrigation • Hydropower
– 283,000 MW potential
– 8.3% use (2009)– 32% of energy
source
Irrigated Land (% of Crop Land)
0
5
10
15
20
25
30
35
40
45
South Asia Middle East &North Africa
East Asia &Pacif ic
Latin America &Caribbean
Sub-SaharanAfrica
North America 388.0 Latin Amer-ica 608.0
Europe 338.0
Africa 283.0
Asia 2,037.
0
Aus-ce67.0
Potential Use
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Response: Finance, investment, policy
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• Physical-infrastructural capital for Africa is high return on investment and resilience
– Accessing adaptation funds to support WRD pays and lead to ‘Concrete adaptation activity’ in Africa
– Enhance policy and governance mechanisms
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Response: No regret Solutions
Eg. Water Storage Continuum for Adaptation (source IWMI)
Present climate vulnerability (pre-adaptation)
Water storage (adaptation strategy)
Future climate vulnerability (post adaptation)
Increased availability and access to water
Increased adaptive capacity
Increased agricultural productivity
Future climate vulnerability < Present climate vulnerability
Increased water security
Maximize benefit through multi-purpose development
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Thank youThe ACPC
www.uneca.org/acpc
Climate Change
Meets Policy
ClimDev-Africa