In2science-8-setcard-235x156 De

Research Topic
Teaser CorbisCoasts, Climate and Society

Measurements, models and analyses for crucial prognoses

What motivates us

Team Building Successful

Network for Future Questions

Hamburg’s climate researchers join forces in a new Cluster of Excellence: nearly two hundred scientists are involved in the CLICCS interdisciplinary network, which analyses not only global climate development, but also advises cities and communities that wish to adapt to future scenarios. HZG experts are contributing to this large project.

Combine harvester in the field.

Photo: Fotolia/Johan Larson

It was just recently that traffic police needed to warn of heavy sand storms sweeping over some regions of northern Germany again - over the motorways and highways. Radio announcements asked drivers to reduce their speed, as visibility on the roads was limited. Gusts of wind had stirred up sand and carried it from the neighbouring fields to the asphalt: after weeks without rain, the fields were dried out - and this was in spring, normally a period with a great deal of precipitation. According to meteorologists at the time, some areas in northern Germany were comparable to deserts.

“Scenarios like this make it clear how much climate change could affect our everyday life in the future,” says Detlef Stammer, climate researcher and director of the Center for Earth System Research and Sustainability (CEN) at the University of Hamburg. Studies show that extreme weather events, such as these droughts, could plague Germany more often in the future. According to Stammer, this makes it even more important for scientists not only to study global climate developments, but also to make regional assessments as well.

Hamburg climate researchers now want to undertake this balancing act in a new Cluster of Excellence research project: “Climate, Climatic Change and Society” (CLICCS). The project began in the Hanseatic city in January, with oceanographer Stammer as spokesperson. Nearly two hundred scientists are engaged in the network, such as meteorologists, geoscientists and experts in climate modelling, but also political scientists and conflict researchers, sociologists, ethnologists and legal experts. Experts from fifteen disciplines in total are networking in the initiative.


Prof. Detlef Stammer.

Prof. Detlef Stammer. Photo: David Ausserhofer

This cooperation between scientists in the natural sciences, social sciences and the humanities has been a hallmark of Hamburg’s climate research for many years. Together the experts initially developed the CliSAP research program, which became a Cluster of Excellence in 2007, for which funding ran out only last year. The German funding body “Deutsche Forschungsgemeinschaft” is now supporting the new CLICCS program until the year 2025 with thirty-eight million Euros. The program is to concentrate even more heavily on regional developments and strategies for local risk prevention.

Societal processes are always taken into account:

  • what climate-relevant measures are put in place, for example, through politics?
  • how do citizens react to climate protection initiatives?
  • how quickly do industries change, particularly those that release a great deal of CO2?

Though these factors heavily influence future climate, computer models have not yet been able to adequately take such developments into account. This is a gap that CLICCS wishes to fill.

“We not only want to know what climate scenarios are possible in purely physical terms, but also what would be especially probable when we take into account physical and social developments equally,” says Stammer, explaining one of the aims of CLICCS. The range of research questions that the Cluster of Excellence wants to address is correspondingly large. Although the network continues to conduct important basic research, it also studies, for example, the social and political risks that climate change involves, and it analyses which protection measures would prove particularly useful in certain regions.

Hamburg Climate Futures Outlook

CLICCS wants to publish important interim results in an annual report, the Hamburg Climate Futures Outlook. It should also repeatedly illustrate to what extent the Paris Climate Agreement targets could be achieved. “There are already a lot of facts on the table; what matters now is developing effective strategies for action,” says Stammer.

Behind the research program, aside from CEN, are the Helmholtz-Zentrum Geesthacht’s (HZG’s) Institute of Coastal Research, as well as HZG’s Climate Service Center Germany (GERICS), the Max Planck Institute for Meteorology and the German Climate Computing Centre, with an additional eight partner institutions involved. The program content is divided into three main topics of focus with a total of fourteen projects: research area A conducts basic scientific research; segment B is dedicated to social science topics; and focus C concentrates on local climate scenarios and the accompanying necessary adaptation strategies.

The range of topics within these branches is large: the experts in area A study different regions, such as the Arctic and tropics or compare air circulation and atmospheric boundary layers in cities and forests. They want to illustrate climate events in more detail using measurements, experiments and satellite data as well as through the development of even more refined computer models. Take, for example, the carbon fluxes in coastal regions: the research teams know from their studies within the CliSAP initiative that coastal seas can absorb a great deal of CO2. In this respect, the sea plays a vital role as a buffer. Without its absorption capacity, the effects of climate change would certainly be much more noticeable today.

The Institute of Coastal Research is Heavily Involved in the CLICCS Cluster Of Excellence

CO2 Uptake in the Coastal Sea

Prof. Corinna Schrumm.

Prof. Corinna Schrumm. Photo: private

“How these processes function precisely, particularly in coastal waters, remains unstudied however,” explains Corinna Schrum, Director of the "System Analysis and Modelling” division at HZG’s Institute of Coastal Research. The oceanographer is leading the project "The Land-Ocean Transition Zone" in theme A. She is also a member of the coordination team for research area C and a member of the CLICCS Steering Committee.

Of particular interest is the perspective on these marine regions, as it is there that temporal, spatial and seasonal variations within the carbon cycles have been observed. A systematic analysis, however, is still missing. “This is something we want to address now,” says Schrum. Her research group also wants to determine whether the coastal seas are absorbing more CO2today than in recent decades.

To this end, the scientists will be combining new and existing data in the coming years. Together with her colleagues at the University of Hamburg and the Max Planck Institute for Meteorology, Schrum’s aim is to create a new ocean model, depicting the global coasts in higher resolution - ICON-Coast, which is later to become a component of a new climate model. With ICON’s help, Schrum’s working group will study the not yet understood exchange processes between the open sea and the coastal regions – and in doing so, contribute to the understanding of global climate development.

Collaboration Between Science and Society

Prof. Daniela Jacob.

Prof. Daniela Jacob. Photo: HZG/Christian Schmid

These interactions between local and global climate, between physical and societal impact factors should, however, not only be studied theoretically. What is also particularly important to the CLICCS teams is the close link to practical application: the insights generated should help decision makers ascertain what measures are useful in climate protection and ensure that cities and communities also have ways to adapt to climate change.

The Climate Service Center Germany (GERICS) at the HZG plays one role here. “We want to bring the scientific and societal sectors together in a dialogue,” explains GERICS Director Daniela Jacob. GERICS scientists therefore are actively exchanging knowledge with different establishments - for example, with agricultural bodies, water authorities, farming and tourism associations, energy companies and shipping experts.

Scientists wish to learn the following from representatives of these bodies: what questions concerning climate change are particularly pressing for them in terms of their future work? Transportation planners, for example, perhaps need to know how often street tunnels will need to be closed in the future, as the tunnels are no longer navigable after severe rain events, Jacob explains. She also points out, “Our job will be to see if today’s knowledge is already sufficient for providing answers to such concrete questions or if we need to mediate a dialogue with an expert from the CLICCS research network.” If the necessary information or a suitable expert is lacking, the scientists can determine whether the question is relevant enough to warrant inclusion as a new aspect in their research work.

Climate research within the cluster, therefore, will not become a one-way street. “We provide our expertise, but we also want to hear from users what knowledge gaps we have perhaps so far overlooked,” explains Jacob.

GERICS is directly involved in two research projects: the scientists, for example, study what types of water management cities within the Hamburg Metropolitan Region need for the future when dealing with varying stress factors, such as floods, heavy rains, storm surges and increasing groundwater levels. According to Jacob, urban planners here are sometimes forced to develop completely new ideas, as existing drainage systems can’t always be easily expanded further. “Hamburg’s sewage system, for example, cannot be randomly expanded at any location for structural reasons,” she says. Instead, large amounts of water could in future, perhaps, be channelled to areas that are suitable as catch basins in the short term.

In another project, GERICS scientific research provides support in how rural areas can arm themselves against the effects of climate change. These communities primarily require local information that is spatially well-resolved. How will the climate develop in the future, particularly in their region? It’s not easy to provide answers - after all, global climate change does not have the same impact everywhere. In some regions, precipitation will increase, while in others it will decrease. The warming itself can also be very different. This is where refined computer models can provide vital answers on climate change. It is crucial that these systems are easy to use. “We want to simplify access to the model results and make them user friendly,” says Jacob. “To this end, we develop customised products for users, providing data and information on possible regional climate change tailored to users in specific regions.“

Furthermore, a system model is under development in a supporting CLICCS project financed by the Helmholtz Association. This model is to provide users with the opportunity to link the effects of socioeconomic factors with the local impacts of climate change by incorporating their own information. In particular, complex relationships and feedbacks are to be identified and effective adaptation measures are to be developed.

Addressing Ethical Climate Questions

For Detlef Stammer, collaboration between the most varying scientific disciplines is indispensible in finding answers to such complex questions. A philosopher, for example, is also contributing to the recently begun project, the CLICCS spokesperson explains. After all, it deals with crucial ethical questions: how will societal conflicts, which climate change will inevitably bring, be resolved as equitably as possible?

In this respect, the mammoth CLICCS project does not only rely on the content of the predecessor CliSAP project. It also benefits organizationally from the experience of the long-practised, interdisciplinary collaboration. “Natural scientists and social scientists generally work very differently, so it requires a certain curiosity and openness,” says Stammer. Over the years, however, the Hamburg climate researchers have grown together as a team. This has paid off today, with the confirmation as a Cluster Of Excellence: “We have a ten-year head start, so our collaboration works outstandingly well today.”

Author: Jenny Niederstadt
Published in the in2science #8 (June 2019)