Transcript Managing Water Resources in a Changing Climate in the Caribbean

UDSMA
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Unit for Sustainable Development and Environment
Organization of American States
Managing Water Resources in a
Changing Climate in the Caribbean
Region
Jan C. Vermeiren
Principal Specialist
UDSMA
USDE
Multiple Challenges
Present Day Challenges:
Securing reliable supply in the face of rising
demand and reduction in the resource base.
Future Challenges:
Planning for potential impact of climate change on
the demand and on the resource base.
Present Day Challenges:
Supply and Demand
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Caribbean
• In several countries, annual per capita freshwater
availability falls far below 1000 cubic meter,
commonly used to measure scarcity.
• Deforestation in upper watersheds reduces water
retention and base flow.
• Existing water storage capacity is inadequate.
• Water distribution systems are overstretched.
• Export agriculture depends increasingly on
irrigation.
• Growth in population, and especially in tourism,
drives increasing demand for water.
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Climate Change:
A Source of Uncertainty
• Traditional water resources management consists in
keeping available supplies and demands in balance.
• Under a changed climate, it is unwise to rely on
historical data as sole guide to the future.
• Use Global Climate models (GCm) to develop
climate change scenarios that outline possible
changes in key climate variables (temperature,
rainfall, sea-level rise).
• Use Impact Assessment to determine/quantify
positive or negative impacts of CC on population,
infrastructure, socio-economic activities and
ecosystems.
Emissions and concentrations of CO2 from unmitigated and stabilising emission scenarios
20
1000
900
850
CO 2 concentration (ppm)
15
10
Anthropogenic CO
2
emissions (GtC/yr)
950
5
800
750
700
650
600
550
500
450
400
0
2000
2050
2100
2150
2200
2250
Unmitigated emissions
2300
2350
350
750 ppm stabilisation
2000 2050 2100 2150 2200 2250 2300 2350
550 ppm stabilisation
Temperature rise
Annual average, from the present day to the 2080s
Change in precipitation
Annual average, from the present day to the 2080s
The rise in sea-level from unmitigated and stabilising emission scenarios
1.2
Sea-level rise (m)
1.0
0.8
0.6
0.4
0.2
0.0
1900
Unmitigated emissions
2000
2100
750 ppm stabilisation
2200
550 ppm stabilisation
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Climate Change Induced Challenges
• Changes in the hydrological cycle will affect rainfall
patterns, which may result in longer and/or more
frequent dry periods, alternated by periods of more
intense rainfall, with negative consequences for
urban and agricultural water supply, and
hydropower generation.
• Sea-level rise may cause salt-water intrusion in
aquifers, in marshlands and areas of brackish water
that feed desalinization plants, and in rivermouths
• Rise in temperature will increase evapotranspiration and increase urban and agricultural
consumption.
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Recent Efforts in Addressing Climate
Change and Water Resources
Management
• UNEP/GEF Country Study on CC Impact on Water
Resources (1997) in Antigua & Barbuda; unable to
quantify impact on water supply due to lack of climate
scenario data.
• National Communications under the UNFCCC identified
possible threats to water supply from CC.
• CPACC Country Policy papers identify need for detailed
vulnerability assessment (VA) of water resources sector.
• UNEP/UNDP/CEHI-GEF project on Integrating
Management of Watersheds and Coastal Areas in
Caribbean SIDS.
• IMPACC, the successor project to CPACC, will include
waters resources VA and adaptation measures.
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Integrating Management of
Watersheds and Coastal Areas in
Caribbean SIDS
• GEF Block B Grant -- February 2000 to December 2001
• Implementing Agencies -- UNDP and UNEP
• Executing Agencies -- UNEP/RCU and CEHI
• Steering Committee -- CARICOM, CEHI, OAS, UNDP.
UNEP
• Participating countries: CARICOM member nations plus
Haiti, the Dominican Republic, and Cuba.
• Assists participating countries in improving watershed
and coastal zone management practices in support of
sustainable development.
Integrating Management of
Watersheds and Coastal Areas in
Caribbean SIDS
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STATUS:
• Currently reviewing national reports on critical issues.
• Regional meeting in Jamaica (February 2001).
• Regional synthesis being developed.
• Full project brief will be submitted to the GEF for
consideration in October 2001.
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Adaptation to CC in the Water Sector
Apply the Precautionary Principle
• Reduce losses in distribution networks.
• Promote conservation and recycling of wastewater.
• Rehabilitate watersheds.
• Construct additional water storage capacity.
• Improve climate monitoring and forecasting for reservoir
and intake management.
• Apply true water pricing, creating incentives for
conservation
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Unit for Sustainable
Development and Environment
CONTACT INFORMATION
Jan C. Vermeiren
Principal Specialist
Tel: (202) 458-3006
Fax: (202) 458-3560
E-mail: [email protected]