Session 1
Coupled regional modelling

Annette Rinke, Burkhardt Rockel

Regional climate system models consist of high-resolution and complex model components for the atmosphere, ocean, ice, land surface, soil, vegetation, and chemicals. Regional information on climate variability and climate change, though urgently needed, is often deemed unreliable. The application of regional climate modelling, which provides more accurate descriptions of regional-to-local scale climate phenomena and interactions, can help us interpret regional observational data and understand the causes of as well as trends in regional climate variability and change.

We encourage submissions that advance our understanding of the processes that determine regional climate variability and of feedback processes between various climate components. These include, but are not limited to, the hydrological cycle, aerosol-cloud-radiation feedbacks, atmosphere-ice-ocean and atmosphere-land surface interactions, and linkages with the ocean ecosystem. Further, we encourage submissions that concern the evaluation of regional models, the impact of regional forcings (e.g. land use, aerosol loading) and sub-grid-scale model parameterizations, and internal model variability, which assess the added value of high-resolution and coupled modelling and which discuss future regional climate projections. The session includes the simulation of extreme events such as storms and their effects (e.g. heavy precipitation or dust pollution) as well as their impacts on coastal erosion and ocean wave height.

Key questions include:

How does the development of the climate depend on the interaction between atmosphere, ocean, ice, and land surfaces? What are the key processes and feedbacks that determine regional climate variability and change?

Session 2
Sea-level rise in a warming climate: from global drivers to coastal impacts

Klaus Grosfeld, Birgit Hünicke, Peter Lemke, Ingo Sasgen

Sea-level rise is one of the farthest-reaching consequences of climate change, threatening densely populated coastal areas around the world. With a projected increase of over one metre within the next few centuries, sea-level rise will affect agricultural areas, large conurbations, industrial centres, habitats and the territories of many countries.

This session will present new research addressing sea-level change from global to local scales. We welcome contributions on global ice, ocean, and atmospheric drivers of sea-level change, on the propagation of the sources, and on changing local mean and extreme sea levels, tackling changes in any part of the world, and in the distant past, recent history and in the future.

Key questions include:

How can we consistently connect observations and simulations of sea-level rise and their impacts across temporal and spatial scales? How do global ice, ocean and atmospheric drivers, as well as land motion, influence mean and extreme sea levels along coastlines? What can we learn from the past? How do natural and anthropogenic sea-level variations affect (societal) coastal risks and ecosystem changes?

Session 3
Land-atmosphere interactions: from measurements to modelling

Birgit Heim, Andreas Marx, Heidrun Matthes, Torsten Sachs, Hans Peter Schmid

The land surface contributes significantly to climate change and its regional differences. In addition, climate impacts mainly occur on the land surface, affecting its key ecosystem services and human well-being. This raises a number of questions concerning e.g. how future changes will influence the interaction between the land surface and the atmospheric boundary, which impacts are expected in relation to water, energy and material flows, and what ecological and socio-economic effects will be produced.

That being said, the meteorological, hydrological, biophysical, biogeochemical, ecological, boundary-layer, and socio-economic processes that underlie the connections between weather/climate, land surface functioning (soil moisture, soil temperature, vegetation, snow, and frozen soil, biogeochemical cycling), and land-use change are not yet fully understood. The complexity of these processes and feedbacks, as well as the wide range of scales involved, are formidable challenges that must be met in order to consistently obtain useful, high-resolution observations.

This session welcomes contributions that improve our understanding of land surface–atmosphere interactions in the following regards:

  • bridging spatial and temporal scales from ground observations towards operational Earth observation and modelling;
  • the application and analyses of local and large-scale field data, observational networks (such as TERENO, ICOS, FLUXNET), and satellite observations for land-atmosphere studies;
  • the linkages between land-cover and land-use changes and climate;
  • the relations between land-use change and climate change, as well as the implications for ecosystem/climate services and socio-economic change.

Key questions include:

How do climate and land use affect ecosystems, water resources, agriculture, and forestry? What are the effects of global climate change on climate-sensitive regions (e.g. mountain areas, highly populated regions, arid/semi-arid regions, the Arctic, and permafrost regions)? How can our understanding of climate-relevant processes be advanced by new technologies and methods for measurement, data science, and modelling?

Session 4
Atmospheric composition and climate: interactions between global and regional scales

Peter Braesicke, Hendrik Elbern, Roland Ruhnke, Bärbel Vogel

The global atmospheric composition-climate system encompasses a broad range of scales and feedbacks. The full chain from global to regional challenges of applying models and atmospheric observations is explored. Chemical budgets are investigated, as well as stratosphere-troposphere exchange, tropopause structure, and aerosol impacts on the global scale. On smaller scales, one focus is on the interactions of clouds, precipitation, and composition; another is on the urban environment and its impact on atmospheric composition and climate, especially with regard to urban heat stresses and air quality including their impacts on humans and ecosystems. We welcome all contributions addressing these challenges.

Key questions include:

What are the dominant regional feedback mechanisms between atmospheric chemistry and circulation, including emissions and surface processes? What are the most important factors shaping interactions between regional climate change and atmospheric composition? What are the potential impacts of climate change and air-quality changes on human health and ecosystems?

Session 5
Extreme events across scales (past, present, future)

Achim Brauer, Frauke Feser, Michael Kunz, Ralf Tiedemann

Extreme meteorological and hydrological events can have various, far-reaching impacts on mankind and play a major role in Earth’s evolution. Moreover, they occur on a wide range of spatial and temporal scales, from minutes to millennia. Combining climate data, palaeo-records, and model simulations allows us to identify and better understand extreme events, their long-term changes, and underlying mechanisms, which is in turn essential to predicting their future probability. This session invites contributions from different disciplines that address: the temporal and spatial variability of short-term extremes, their driving factors and how they develop under changing climate conditions; the relation between extreme events and large-scale changes in ocean-atmosphere circulation and feedback on a broad range of time scales from the decadal to palaeo; and identifying the dynamics, causes, and impacts of tipping points that produce critical transitions in the climate system.

Key questions include:

How and why has the severity and frequency of extreme weather events changed over the past few decades? How do we expect climate to evolve in the future? Which mechanisms, processes and regional climate patterns intensify abrupt climate changes during interglacials and glacial-interglacial transitions? How do these patterns differ compared to the last interglacial, the Eemian, when the average temperature was roughly 1–2 °C higher than it is now?

Session 6
Climate change adaptation as societal challenge

Beate Ratter, Reimund Schwarze

Climate change adaptation is more than a technical matter: it is a major societal challenge encompassing social, economic, and cultural aspects alike. Further, large research gaps and considerable uncertainties concerning political and governance aspects, as well as socio-cultural barriers to adaptation, still need to be addressed. However, it is the reluctance to take action, rather than a knowledge deficit with regard to climate change, that represents the most pressing issue.

The various environmental uncertainties in different societies must be addressed through regionally and socially embedded adaptation measures, disaster prevention, and mitigation strategies. What insights and advances have recently been achieved in climate change adaptation research? How can environmental corporate social responsibility be attained? How can scientific findings be transformed into societal action? As this session will show, adaptation involves overcoming a broad range of obstacles so as to support vulnerability reduction, enhance social resilience, and help minimise the negative effects of climate change.

Key questions include:

What societal risks does climate change entail? Which socio-cultural barriers to adaptation have to be overcome? How can adaptation measures, disaster prevention, and mitigation strategies be successfully combined to tackle climate change? How can scientific findings be transformed into societal action?