Climatic change in the Alps - OECD.org - OECD · © 2006 Martin Beniston University of Geneva, Switzerland-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 1 2 3 4 5 6 7 8 9 10 Changes in snow duration

© 2006 Martin BenistonUniversity of Geneva, Switzerland

Climatic change in the AlpsProf. Martin BenistonUniversity of Geneva, [email protected]

Wengen-2006 Workshop


Overview

IntroductionCurrent and future climate in the AlpsPotential impactsConclusions

Introduction Climate Impacts Conclusions


1IntroductionCurrent and future climate in the AlpsPotential impactsConclusions



The Alps are at the crossroads of numerous weather regimes

Saharan

Mediterranean

Atlantic

Continental

Polar



Evolution of global and alpine temperatures, 1901-2000

-1.5

-1

-0.5

0

0.5

1

1.5

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

GlobalAlps

Beniston, M

., 2004: Clim

aticC

hange and Impacts: A

n O

verviewFocusing

on Sw

itzerland. Kluw

erAcadem

icP

ublichers, 296 pp.

Cha

nge

in T

rela

tive

to 1

961-

1990

[°C

]






Summer temperatures in Basel, Switzerland, 1901-2004Beniston, M., 2004:

Geophys. Res. Letters

-3

-2

-1

0

1

2

3

4

5

6

7

1901

1911

1921

1931

1941

1951

1961

1971

1981

1991

2001

Sum

mer

Tmax

anom

aly

(Dep

artu

res

from

1961

-199

0 m

eans

[°C

]


19471952

2003

2006


Summer rainfall in the central Swiss Alps

-100

-50

0

50

100

150

200

1930

1935

1940

1945

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

EngelbergAltdorfSt Gallen

2005

-1°C

0°C

+1°C

+2°C

Temperature anomalies [°C]Precipitation anomalies [mm]



Climate futures

-0.4-0.2

00.20.40.6

1.0

1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

ΔT

with

resp

ect t

o 20

thce

ntur

y [°

C]

0.8

2.0

3.0

4.0

5.0

6.0

2050 2100

IPC

C, 2001

Mann et al., G

RL, 1999

B2

A2



Mean

Changes in summer Tmax (june-july-august)(Differences between 2071-2100 and 1961-1990)(HIRHAM Regional Climate Model; A2 Scenario)

90% quantile

+2 +4 +6 +8 +10 +12°C

EU-PR

UD

ENC

E Project, University

ofFribourg



Beniston and D

iaz, 2004: Global &

Planetary

Change

20

25

30

35

40

45

1960

1965

1970

1975

1980

1985

2075

2080

2085

2090

2095

2100

2070

1961-1990

2071-2100

Average90% quantile

B2A2

Tmax mean and 90% quantiles for current and future climates in Basel

2003

2003



Changes in summer precipitation (JAS)(Difference in % between 2071-2100 and 1961-1990)

(HIRHAM Regional Climate Model; A2 Scenario) Christensen, J. H

. and Christensen, O

. B., N

ature, 2003

Seasonal precipitation Precipitation > 50 mm/day

-40 -30 -20 -10 0 +10 +20 +30 +40% change



Changes in seasonalprecipitation in the Alps

(HIRHAM RCM)

250

500

Winter Spring Summer Autumn

1961-1990Se

ason

alpr

ecip

itatio

n[m

m]

450

400

350

300

2071-2100 (A2)

2071-2100 (B2)

Beniston, G

RL, 2006

Annual: 1605 mmAnnual: 1591 mmAnnual: 1597 mm






Environment and Society: subtle linkagesEnvironment

Society

Tourism

Hydrologicalcycle

Mountainagriculture

Slope stabilityCryosphere Biosphere

Safety of mountain communitiesCommunication routes

Hydropower


2000

Glacier retreat:Tschierva Glacier, EngadineC

ourt

esy:

Max

Mai

sch

Uni

vers

ity o

f Zür

ich,

Sw

itzer

land

+3°C?2050?



-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 31

2

3

4

5

6

7

8

9

10

Changes in snow duration

255075100125150175200225250275300325350

Duration[days]

2081-20902091-21002071-2080

Säntis:Future climate

Arosa (1,600 m):Current climate

Arosa:Future climate

2071

-208

0

2081

-209

0

2091

-210

0

Mea

n w

inte

rpr

ecip

itatio

n [m

m/d

ay]

Mean winter temperature [°C]Beniston, M., et al., 2003:Theor. & Appl. Clim.

75

300

Säntis (2,500 m):Current climate



Changes in runoff in the central Alps (HIRHAM RCM)

Mea

n30

-yea

r run

off[

mm

/day

]

0

1

2

3

4

5

6

1 31 61 91 121 151 181 211 241 271 301 331 361Calendar day


1961-1990

2071-2100

Enhancedflood risk

Enhanceddrought risk

+90% -5% -45% -20%



0

10

60


Num

bero

feve

tsbe

yond

99%

qua

ntile

Changes in extremeprecipitation in the Alps

(HIRHAM RCM)

1961-1990

2071-2100 (A2)

2071-2100 (B2)

Beniston, G

RL, 2006

108 events

127 events

141 events40

20

30

50

70



Consequences for floods:the buffering effects of snow

Runoff

Floodlevel



Examples of short-livedcatastrophic events



Disturbance to Alpine vegetation

…to this?

From this…






Pressures on socio-economicsystems

The Alps are a region with a high population density, high-value economic activity andexpensive infrastructureClimate-induced disruptions to the naturalenvironment will have significant impacts on socio-economic systems

Lack of snow winter tourismChanges in seasonality of runoff hydropowerExtreme events and geomorphologic risks enhancedcosts for the insurance industryChanges in heat and moisture régimes disruptions to ecosystems and agriculture



Prof. Martin BenistonUniversity of Geneva, [email protected]

Wengen-2006 Workshop

Documents

Climatic change in the Alps - OECD.org - OECD · © 2006 Martin Beniston University of Geneva, Switzerland-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 1 2 3 4 5 6 7 8 9 10 Changes in snow duration