Climate Change:the Swiss Perspective

Dr. Lorenz Martin

Oeschger Centre for Climate Change Research andInstitute of Applied Physics

University of Bern

Prologue

Climate change is already taking place …

Töss, August 2003

Brienz, August 2005

Prologue

Climate change is already taking place …

(IPCC, 2007)

Prologue

Climate change is already taking place …

(IP

CC

, 2

00

7)

black: observed temperature anomalyred: modelled temperature anomaly, with anthropogenic factorsblue: modelled temperature anomaly, without anthropogenic factors

Prologue

Climate change is already taking place … … and we know why

Sie

ge

nth

ale

r e

t a

l., (

20

05

)Jo

os

& S

pa

hn

i (2

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8)

last 10‘000years

last 200years

last 50years

Outline

Prologue

> How can we determine the human impact on climate?

> What will happen with the climate in the future?

> What can we do against climate change?

Conclusions

How can we determine the human impact on climate?

The global climate system

How can we determine the human impact on climate?

The greenhouse effect

(Dennis Hartmann)

without greenhouseeffect: -18°C globalaverage surfacetemperature

with greenhouseeffect: 14°C globalaverage surfacetemperature

How can we determine the human impact on climate?

Radiative forcing todaywith respect to 1750

How can we determine the human impact on climate?

Excursus: Measuring water vapourand clouds

> Water vapour is the most important greenhouse gas(approx. 65% of the greenhouse effect)

> The water vapour feedback is approx. 0.5°C/°C

> Clouds (water and ice droplets) have a strong influence on the radiation balance in the atmosphere

> Water vapour and cloud measurements are essential for the understanding of the climate system and for weather prediction

How can we determine the human impact on climate?

A new instrument for ground-based water vapour and cloud measurements

ASMUWARA, the all-sky multi-wavelength radiometerIn operation at the Institute of Applied Physics, Univ. of Bern

How can we determine the human impact on climate?

A new instrument for ground-based water vapour and cloud measurements

(Martin, 2006)

How can we determine the human impact on climate?

A new instrument for ground-based water vapour and cloud measurements

above: temperature profiles over Bern

left: multispectral images of clouds

MW

IR(Martin, 2003)

What will happen with the climate in the future?

CO2 emission scenarios …

rapid economic growth,technological changes,fossil intensive energy

sustainable economiesand societies,reduced econ. growth

rapid economic growth,technological changes,non-fossil energy

(IPCC, 2001)

What will happen with the climate in the future?

… and the expected temperature change

Emissions

(IPCC, 2001)

What will happen with the climate in the future?

… and the expected temperature change

(IPCC, 2007)

non-fossilscenario

fossilscenario

What will happen with the climate in the future?

Alpine temperature and humidity towards 2100

2071-2100 minus 1961-1990 (11 different climate models):

Temperature [ºC]

Jan Mar May Jul Sep Nov

7

6

5

4

3

2

Precipitation [%]

+60

+40

+20

0

-20

-40

-60

Jan Mar May Jul Sep Nov

(Ja

cob

, 2

00

5)

=> warm and humid winters, hot and dry summers

What will happen with the climate in the future?

What will happen with the climatein the future? Some examples

(IPCC, 2001)

What will happen with the climate in the future?

Protect or insure?

Present Climate

Future Climate ??

protect insure

(Schär, 2004; Heck, SwissRE)

What will happen with the climate in the future?

Melting glaciers and their impact onriver discharge

(Sh

ab

alo

va e

t a

l 20

03

)

Seasonal water discharge of river Rhineat Rheinfelden today and in 2100 (+4.8°C)

(Ste

ine

r, 2

00

5)

1850

2003

What will happen with the climate in the future?

Alpine temperature and humidity towards 2100

winter summer

What can we do against climate change?

What can we do against climate change?

Two strategies:

Adaptation (Anpassung)> adapt to climate change> typical example: construct river dams against floods> immediate effect, but local impact

Mitigation (Milderung)> mitigate climate change> typical example: use bike instead of car> global impact, but delayed effect

What can we do against climate change?

The efficiency of regulations …

catalyser in cars in 1986

low-sulphur fuel oil in the 70s

(BFS, BAFU, 2009)

What can we do against climate change?

… and the impact of regulationson the economy

Economic performance is not affected byenvironmental regulations, taxes, etc.!

(OECD, OcCC 2005)

Conclusions

Conclusions

Climate change is taking place,and the reasons for climate change are known.

Combating climate change> costs -- but doing nothing will cost much more!> requires global cooperation and investments

for the far future.> is a matter of society, economy and politics.

Every measure (adaptation and mitigation) is helpful.

Appendix

References

IPCC: International Panel onClimate Change

part of UNO, founded in 1988

reports approx every 5 years

Working group 1 report 2007:• 600 authors• 40 countries• 600 peer reviewers

http://www.ipcc.ch

Appendix

Climate research in Switzerland andat the University of Bern

NCCR Climate (http://www.nccr-climate.unibe.ch)> Swiss centre of excellence for climate research> start 2001, expected end 2013, NFS funded> 130 researchers, 13 institutions (Universities, ETH, etc.)> University of Bern is leading house and coordinator

Oeschger Centre (http://www.oeschger.unibe.ch)> Climate research centre at the University of Bern> coordinates, funds and promotes climate research> interdisciplinary (sciences, humanities, economy, law, …)> Graduate School of Climate Sciences