Climate Sense

[

] 77

Challenges for the

climate services in Switzerland

C. Appenzeller, A. P. Weigel, M. Begert, S. C. Scherrer, M. Croci-Maspoli, G. Seiz, N. Foppa, A. Rubli,

Climate Division, Swiss Federal Office of Meteorology and Climatology MeteoSwiss

rowing concern about global climate change has

increased awareness of the importance of providing

accurate climate information for the past, present and

future. The current state of the Swiss climate has become an

active element in public debate. Reports on the warmest month

or season on record, or articles on the impact of once-in-a-

hundred-years precipitation events, are headlines in the daily

news. Historically, climatology at the Swiss Federal Office

of Meteorology and Climatology (MeteoSwiss) has primarily

focused on the observation of weather elements, data quality

control, homogenization and data archiving, and subse-

quently calculating and reporting basic statistical quantities

such as monthly temperature and precipitation summaries.

In retrospect, this work was fundamental in triggering the

development of national climate monitoring infrastructures.

Without them, we would not know how much the climate has

changed in recent years.

The growing importance of issues related to climate change has

increased the demand for new climate services and poses a wide

range of challenges to MeteoSwiss. Switzerland, due to

its mountainous topography, seems to be particularly

exposed to climate change. Indeed, over the period 1971

to 2008 Switzerland has experienced a temperature rise of

1.75°C, which is twice the globally averaged land surface

trend. Climate projections suggest that this warming will

continue and by the middle of this century affect tourism,

biodiversity, water resources, hydropower generation

and many other sectors of socioeconomic and ecologi-

cal relevance. A specific example is Swiss winter tourism.

Many ski resorts are located at an elevation of 1,000 to

1,500 metres above sea level. One of our research projects

revealed that the 0°C line in winter is projected to rise

from roughly 900 metres today to 1,250 metres above

sea level in the next 50 years. This means that by 2050

dozens of ski resorts may not have enough snow in winter

to continue to exist. Information of this kind is crucial for

those in charge of regional planning as well as for investors

in holiday resorts.

This example illustrates that, although the problem

of climate change is a global one, its effective conse-

quences can be highly localized and site-specific. In the

ideal case, climate services would therefore be custom-

tailored to the demands of each region in Switzerland.

This not only refers to future climate projections, but

also to observations of the present day climate, given

that any climate change signal can only be detected and

quantified if high quality observations are available. It

is therefore a key focus of our service to ensure that

climate monitoring is secured in sufficient spatial reso-

lution and on a high quality level.

Climate observation and monitoring

Switzerland has a long tradition of climate observa-

tion. Some temperature series date back to the middle

of the 18th century. Since 1864 a dense network of

meteorological surface stations has been maintained

and meteorological measurements have been recorded

systematically all over the country. Many of these

stations are still in operation today. They are part of

our official meteorological surface station network,

SwissMetNet. The most valuable climatological stations

within SwissMetNet are pooled together in the Swiss

National Basic Climatological Network (Swiss NBCN).

Research is under way to digitize and homogenize most

overnance

and

olicy

Monitoring the high alpine climate of Jungfraujoch at 3,580 metres

Image: Ruedi Wyss