World Meteorological OrganizationWorking together in weather, climate and water

WMO: Climate and Water Department www.wmo.int

WMO

AVINASH TYAGIDirector, Climate and Water Department

WORLD METEOROLOGICAL ORGANISATION

Session 1.3.3: Managing water related risks in changing climateSession 1.3.3: Managing water related risks in changing climateFifth World Water ForumFifth World Water Forum

16-22 March, 2009, Istanbul, TURKEY16-22 March, 2009, Istanbul, TURKEY

Impacts of Climate Change Impacts of Climate Change on water related riskson water related risks

IntroductionIntroduction

What is global warming?What is global warming?

“Global warming” refers to increases in global temperatures as a result of an accumulation of greenhouse gases in the atmosphere.

Greenhouse gases,

such as CO2 , CH4, N2O, HFCS,…

Potential Impacts of Climate ChangePotential Impacts of Climate Change

Precipitation form, timing and quantity

Sea level rise

Air temperature

OBSERVATIONSOBSERVATIONS

Global mean temperatures Global mean temperatures

100 0.0740.018

50 0.1280.026

Warmest 12 years:1998,2005,2003,2002,2004,2006, 2001,1997,1995,1999,1990,2000

Period Rate

Years /decade

Sea level in 20Sea level in 20thth century century

Rates of sea level rise:•1.8 + 0.5 mm yr-1, 1961-2003•1.7 + 0.5 mm yr-1, 20th Century•3.1 + 0.7 mm yr-1, 1993-2003

SPM-3b

Smoothed annual anomalies for precipitation (%) over land from 1900 to 2005; other regions are dominated by variability.

Changes in Land precipitation Changes in Land precipitation

Increases

Decreases

Between 18 and 21 mm/yrBetween 21 and 27 mm/yrBetween 27 and 30 mm/yrBetween 30 and 36 mm/yr

Between -21 and -24 mm/yrBetween -18 and -21 mm/yrBetween -15 and -18 mm/yrBetween -9 and -12 mm/yrBetween -6 and -9 mm/yrBetween -3 and -6 mm/yr Between 0 and -3 mm/yr

Wet Season

Dry Season

Source: Boer et al (2007)

Effects on the hydrological cycleEffects on the hydrological cycle

• Precipitations

• Evaporation

• Soil moisture

• Glaciers

• Streamflow

• Groundwater

• Floods

• Low flows

• Water Demand

Base flows in rivers Base flows in rivers

1

20

40

60

81

900101 25.days/mm 9301 9401 9501 9601 9701 9801 9901 0001 0101 YYYMM

A

A

A site 2120102 020120102 Ciliwung at Ciliwung-Katulampa Debit m3/det .734units/mm Origin 1

0

2 0 0 0

4 0 0 0

6 0 0 0

6 9 3 0

7 7 0 1 0 1 8 0 0 1 8 3 0 1 8 6 0 1 8 9 0 1 9 2 0 1 9 5 0 1 9 8 0 1Y Y M M

A

A

A s i t e 3 2 7 0 0 0 1 0 3 0 2 7 0 0 0 1 S B A r i t o a t S B a r i t o - M T e w e h0

100

200

300

400

500

610

760101 7701 7801 7901 8001 8101 8201 8301 8401 8501 YYMM

A

A

A site 4570006 040570006 S Larona at S Larona-Warau Debit m3/det

Barito

Ciliwung

Larona

Source: Water R&D Center, Bandung (2007).

Perth inflows

0

100

200

300

400

500

600

700

800

900

1000

YEAR

1913

1917

1921

1925

1929

1933

1937

1941

1945

1949

1953

1957

1961

1965

1969

1973

1977

1981

1985

1989

1993

1997

2001

Tota

l ann

ual i

nflo

w (G

L)

Inflow 1911 to 1974 (338 GL av) 1975 to 2001 (167 GL av)

Note: A year is taken as May to April and labelled year is start (winter) of year Year 2001 inflows are not for a full year

Runoff from Finland:

February

0

1000

2000

3000

4000

5000

1912 1922 1932 1942 1952 1962 1972 1982 1992 2002

Year

Mea

n f

low

(m

3 s

-1)

Potential ImpactsPotential Impacts

• All major socio-economic sectors will be affected, with a wide range of regional impacts:– Water

– Ecosystems

– Food

– Coastal systems and low-lying areas

– Industry, settlement and society

– Health

• Through climate change and the effects of e.g… - changes in the hydrological cycle and water balance - sea level rise - increased water temperatures

• Through increased climate variability in the form of more serious and frequent extremes, such as floods and droughts

Global warming will hit through waterGlobal warming will hit through water

Source:TJK

Increasing number of hydrological Increasing number of hydrological extremesextremes

• Meuse river, December 1993

• Rhine river (secondary channel in floodplain), August 2003

There’s a consistent 50-year upward trend in every region except Oceania.

Changes in major floods 1950-2000Changes in major floods 1950-2000

Flood damages are increasingFlood damages are increasing

Relative Vulnerability Relative Vulnerability of coastal deltasof coastal deltas

Demographic ChangesDemographic Changes

(i) Changes in socio-economic systems

Land-use change, increasing exposure and damage potential – floodplain development, growing wealth in flood-prone areas

(ii) Changes in terrestrial systems

Land-cover change - urbanization, deforestation, elimination of wetlands and floodplains, river regulation

(iii) Changes in climate and atmospheric system

Holding capacity of the atmosphere, intense precipitation, seasonality, circulation patterns

Reasons for changes in Reasons for changes in flood risk and vulnerabilityflood risk and vulnerability

Sou

rce:

Kun

dzew

icz

& S

chel

lnhu

ber,

200

4

Flood Damages as Percent of GDP(Based on damages and GDP data in 2000 dollars)

0.0%

0.1%

0.1%

0.2%

0.2%

0.3%

0.3%

0.4%

0.4%

0.5%

0.5%

1900

1903

1906

1909

1912

1915

1918

1921

1924

1927

1930

1933

1936

1939

1942

1945

1948

1951

1954

1957

1960

1963

1966

1969

1972

1975

1978

1981

1984

1987

1990

1993

1996

1999

2002

2005

Dir

ect

floo

d da

mag

es a

s pe

rcen

t of

GD

P

0%

5%

10%

15%

20%

25%

Tota

l flo

od d

amag

es a

s pe

rcen

t of

GD

P

Direct damages as percent of GDP

Total damages as percent of GDP

MississippiRiver Valley

Ohio & Lower Mississippi River

Basins

Kansas &Missouri Rivers

HurricaneDiane

Hurricane Agnes

Teton DamFailure

Midwest Floods

138%

61%

99%

PROJECTIONSPROJECTIONS

2121stst Century CenturyIs this going to be the Is this going to be the flood flood century?century?

(Too much water )(Too much water )

……or the or the drought drought century?century?

Probability distributions: temperatures Probability distributions: temperatures

(Adapted from Climate – Into the 21st Century, WMO, 2003, Cambridge University Press)

HazardsHazards

– Floods– Droughts– Flow regime

changes

changes in the averages/ trends

““Climate change: the hydrologic cycleClimate change: the hydrologic cycle””

changes in variability (magnitude, severity, duration)

General Circulation Models (GCMs)General Circulation Models (GCMs) to estimate future climate variables.to estimate future climate variables.

GCMs are constantly improving, and converging to observations.

Reichler and Kim (2007) BAMS

AOGCMs

• discretise the equations of fluid motion

•parameterize processes at the subgrid scale.

Due to model uncertainty, an ensemble of models is more accurate than any single model.

Temperature projections are much better than precipitation projections. Climate Impacts Group (2007)

Figure 10.12

AR4 WGIFig. 10.12

Annual mean changes of precipitation, soil moisture, runoff and evaporation

(2080-2099 relative to 1980-1999)

SRES A1B scenario

AR4 WGIFig. 10.18Changes in extremesChanges in extremes

2080–2099 minus 1980–1999 for the A1B scenario

annual total precipitation /number of wet days

annual maximumnumber of consecutivedry days

Climate change on NZ east coast: Climate change on NZ east coast: Unirrigated drought risk, 2080sUnirrigated drought risk, 2080s

“Low-medium” scenario “Medium-high” scenario

Coastal floodingCoastal floodingChange from the present day to the 2080sChange from the present day to the 2080s

Unmitigated emissions

Stabilisation at 750 ppm Stabilisation at 550 ppm

99/81235Hadley Center

Changes in river runoff from the present day to the 2080s

Unmitigated emissions

Stabilisation of CO2 at 750 ppm Stabilisation of CO2 at 550 ppm

–75 –50 –25 –5 to 5 25 50 75Change in annual runoff (%)

Downscaling from Global to Basin LevelsDownscaling from Global to Basin Levels

We must downscale GCM data to an appropriate resolution for hydrological predictions.

Resistance StrategiesResistance Strategies

““Resistance” strategies focus mainly on the hazard (flood, Resistance” strategies focus mainly on the hazard (flood, drought, etc.) by aiming at preventiondrought, etc.) by aiming at prevention

Rainwater Harvesting:Rainwater Harvesting:Reservoir in a buildingReservoir in a building

More efficient irrigation systems

DEMAND Management

Year 1 Year 2 Year 3 Year 4

Seasonal climate forecast anomalies

Climate monitoring

Malaria monitoring at sentinel sites

Climate Alert System (CAS)Climate Alert System (CAS)ExamplesExamples

Climate Alert: low precip sets stage

Climate Alert: high precip may trigger

High precip; sentinels activated

Monthly, Seasonal, Interannual MonitoringMonthly, Seasonal, Interannual Monitoring

El Niño and La NiñaEl Niño and La Niña

El Niño (1997)

La Niña (1988)

Regional Climate Outlook Forums

GHACOF: Greater Horn of Africa COFSARCOF: Southern Africa COFPRESAO: Prévision Saisonnière en Afrique de l’OuestPRESAC: Prévision Saisonnière en Afrique CentraleFOCRAII: Forum On regional Climate monitoring, assessment and prediction for Regional Association II (Asia)

SSACOF: Southeast of South America COFWCSACOF: Western Coast of South America COFCCOF: Caribbean COFFCCA: Foro Regional del Clima de América CentralPICOF: Pacific Islands COFSEECOF: SouthEastern Europe COF

Thank you

<0.04oC/year Between 0.04 and 0.07 oC/year > 0.07 oC/year

<0.04oC/year Betweem 0.04 and 0.07 oC/year > 0.07 oC/year

Maximum Temperature

Minimum Temperature

SOurce: Boer et al (2007)