Climate Sense

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essential that the forecasts are reliable and that the underlying

uncertainties are appropriately quantified. This is a non-trivial

task which involves a series of post-processing steps and has

become a research focus of our climate service.

Concerning longer timescales, our observations clearly show

that the climate has changed over the last decades. At the same

time, climate model predictions as summarized, for example

by the Intergovernmental Panel on Climate Change, indicate

that the climate will continue to warm. While the magnitude

of climate change depends on the future development of the

global economy, technological innovation and policies, local

and regional adaptation strategies can only be formulated if

sound climate information is available, which in turn requires

an involvement of the national climate services. For example,

regional observations and projections of summer mean temper-

atures and precipitation for northern Switzerland have been

determined under the lead of the Swiss national advisory board

on climate change (OcCC, 2007).

However, most stakeholders

require information that is even more specific, and we have to

answer questions such as: Will there be a stronger temperature

change at higher altitudes? How does the precipitation pattern

change in a region or at a specific site? For example, the canton of

Valais or the city of Geneva. What about changes in the frequency

of extreme weather? Will there be more strong storms such as

those in December 1999, floods like in August 2005 or heat waves

as in 2003? And again – how certain are these projections?

An answer to these complex questions requires close collab-

oration with the Swiss and international climate research

community. Since 2001, our office has been an active partner in

the National Centre of Competence in Research on Climate, a

scientific network bringing together more than 100 researchers

from national partner institutions with the aim of better under-

standing the climate system by carrying out interdisciplinary

research on its variability and interactions. At the same time,

MeteoSwiss has participated in international research projects

such as EU FP6 ENSEMBLES – a largescale European research

initiative to provide objective probabilistic estimates

of uncertainty in future climate on the basis of a large

ensemble of global- and regional-scale climate model

simulations.

While the duration of such programmes and initi-

atives is usually limited, the user demand for high

quality climate information is continuously growing

and requires the establishment of a more permanent

framework to guarantee this kind of service. An

integral component of such a framework could be

provided by the Center for Climate Systems Modeling

(C2SM) located at the Swiss Federal Institute of

Technology in Zurich, which was established in

autumn 2008 by Zurich based institutions, includ-

ing MeteoSwiss. The C2SM has the potential to act

as a long-term interface between climate research on

the one hand and end-user oriented climate services

on the other, and may form an integral part in the

development of a national adaptation strategy.

Maintaining a reliable, high resolution measure-

ment network that provides high quality local and

regional climate information as well as climate change

projections is among the most challenging tasks of

our climate service. Together with our partners from

research, the economy and public sector we can help

to give answers to many climate related questions.

However, we also need to improve dialogue between

our service and stakeholders. Switzerland started

with the development of a national adaptation strat-

egy. Climate information will be the backbone of this

strategy. A constructive dialogue will help to set the

focus of our services. However, users must know the

potential and limitations of our products if they want

to achieve optimal benefits. The quantification and

communication of prediction uncertainty is one of the

key challenges in this context.

Climate projection for northern Switzerland

Source: Federal Office of Meteorology and Climatology MeteoSwiss/Institute for Atmospheric and Climate Science ETH

Observed (1864-2008) and projected (1990-2070) summer temperature (left, in °C) and precipitation anomalies (right, in per cent) for northern Switzerland

with respect to 1961-1990. The grey areas show the uncertainty range of the projection (5-95 per cent confidence), assuming that no quick measures are

implemented to reduce greenhouse gas emissions