With the Paris Agreement, the international community agreed in 2015 to limit global warming to a maximum of 1.5 degrees above pre-industrial levels by 2100. The “IPCC Special Report on 1.5 ° C Global Warming” shows that this is possible. Nevertheless, a warming of the global mean temperature will bring numerous changes for our lives: for our health, for urban development, for our forests and many other areas of life. Cluster II of the Helmholtz Climate Initiative is researching what this can actually mean in a total of nine projects. The results will simulate or model future situations. This will open up new fundamentals for stakeholders and decision-makers in their actions - for example when it comes to which forests will grow in Germany in the future, what our mobility looks like or how certain infectious diseases or allergies could develop.


Participating Centers:



  • T. Jung, L. Samaniego, G. Lohmann, S. Kollet, P. Braesicke, K. Matthes, K. Sieck, F. Feser, E. Zorita

Aim of the project

Preparing, generating and providing existing and novel scenario data of drivers of European extreme events.

The “Drivers” Project will combine existing scenario-based simulations such as HAPPI-DE and EURO-CORDEX with novel (high-resolution) simulations focusing on natural drivers and climate change computations. “Jet stream manipulation” and carefully set up “time slice” experiments will generate meteorological data sets for contemporary and future time horizons. Emphasis will be placed on possible European extreme events (like in the summer of 2018) in 2030, 2050 and 2100 with assumed temperature pathways with warmings by 1.5°C, 2°C and 4°C. Internal variability as well as external drivers will be investigated in detail. These new simulations will be dynamically downscaled with a groundwater-to-atmosphere simulation approach to investigate relevant feedbacks in the terrestrial system that are crucial for impact studies. Meteorological forces also drive land surface and hydrological models: These can evaluate a multi-model ensemble of selected relevant terrestrial climate variables (tECVs) of WMO/GCOS, such as discharge and ground moisture, with a so far unmatched resolution of 1 km over Germany. This accuracy also allows estimating key sensitivities and uncertainties for different tECVs and related indicators for hydrological and agricultural droughts. Finally, this project aims to translate climate change signals into useful information for the subsequent impact models used in other projects.

Participating Centers:
▪ U. Schlink, G. Lecrivain, I. Heinrich, T. Esch, X. Zhu, R. Weisse, S. Knapp

Aim of the project
Urban areas are tremendously complex systems: Due to heterogeneous constructed structures that interact with the
atmosphere, their climatological conditions are subject to extremely localized fluctuations. Climate change related
hazards have to be captured with “state of the art” high resolution techniques to account for their negative
health impacts on urban residents. Consequently, this project incorporates a system perspective in order
to support more targeted and effective climate adaptation measures. Climate extremes and their impacts intensify
in urban regions: urban heat islands, droughts, storms and floods impair human health, green and built
infrastructure. This project will prepare and analyse existing and future scenarios as well as impacts of urban
extreme heat, drought and wind in Germany. Coastal cities and urbanized coastal areas (on- and offshore) are
particularly vulnerable and additionally exposed to storm surges and extreme waves as well as compound events
(e.g. simultaneous flooding from sea and the hinterland). Our research will provide a comprehensive
assessment of climate related risks for a number of key cities that suffer from climate extremes and will be
extended to further regions relevant for sister projects.

Participating Centers:
▪ M. Kunz, H. Apel, D. Borchardt

Aim of the project
Over recent years, the frequency and intensity of heavy rainfall has substantially increased in most parts of Germany and Europe. Furthermore, episodes from several days to weeks with an exceptional high number of quasi­stationary thunderstorms related to atmospheric blocking have been observed that cause locally extreme accumulated precipitation. At the same time, the frequency and duration of dry weather and low water drain periods has increased, changing the blending and transport capacities of entire river networks. Consequently, urban flash floods and related damage to buildings / infrastructures and water pollution from untreated sewage discharges are becoming more frequent, making appropriate adaptation strategies indispensable. The project “Urban flash floods and sewerage” aims to simulate the entire effect chain: from extreme rainfall scenarios including expected changes and temporal clustering through overflow and flooding to the resulting damages for household / infrastructure and the effect of storm water overflow  on water quality and ecology. The project has several novel and unique aspects, such as replicating the entire effect chain, investigatin how large-scale flow patterns drive local-scale precipitation extremes, and developing a catalogue of adaptation strategies including structural (e.g. design of sewer and wastewater treatment plants) and non-structural (e.g. communication, risk transfer, private precaution) measures. The concept is tested in a showcase study city.

Participating Centers:
▪ With contributions from DLR-FK, UFZ, DLR-DFD
▪ B. Lenz

Aim of the project
In the future, cities and rural regions will have to deal much more intensively with adaptation to climate change in
order to remain places of high quality of life and ensured mobility. Aims of the project are to (1) Investigate future
mobility in changing climate conditions, weather extremes and altered urban structures, (2) Quantify mobility,
emissions and energy consumption in such conditions, and (3) Derive recommendations for adaption and
socio­economic implications.

Participating Centers:
▪ S. Castell, H-H. Thulke, C. Traidl-Hoffmann

Aim of the project
Vector-borne infectious diseases and pollen-driven allergies are intuitively understood as associated climate
changes. However, the use of causal understanding to forecast future prevention strategies has limited examples
in applied literature. Consequently, this two-part project focuses on a health case for climate-specific prevention
strategies derived from ecologically explicit data and system modelling. Therefore, on the one hand, future
developments of a climate-sensitive infectious disease, i.e. tick-borne borreliosis, will be modelled. On the other
hand, we will generate temporal-spatial forecast models regarding pollen and spores and investigate the
correlation between thunderstorms and asthma attacks. We will use input from the following projects: “Drivers”,
i.e. climate indicators, and “Urban flash floods and sewerage”, i.e. thunderstorm projections. We will work closely
with GERICS and DLR. The subproject concentrating on borreliosis will integrate serological data from project
“Health in NAKO & Rhineland” and exposure risk maps based on ecologically predicted abundance models for
alternative climatic scenarios (30, 50, 80 years). Regarding allergies, we will retrospectively (20 years) analyse
pollen data for Europe and spore data for Bavaria (Germany). Pollen season indices (e.g. duration and intensity)
will be investigated from more than 40 locations in Europe. These datasets will be analysed in the context of
recent annual changes in maximum temperature and minimum temperature associated with anthropogenic
climate change.

Participating Centers:
▪ A. Peters, T. Pischon, M. Breteler, T. Waterboer, S. Castell

Aim of the project
The NAKO and the Rhineland Study assess the health of more than 200.000 adults, phenotyping the participants repeatedly throughout the years. These cohort studies provide a unique opportunity to investigate the association between satellite-based spatio-temporal resolved weather parameters, contextual factors and early physiological responses to weather. We will focus on the impact of weather on cardiovascular and cancer diseases, metabolic and cognitive function as well as mental health and assess the prevalence of Lyme disease providing a direct link to project 5. Finally, we will explore the joint impact of temperature and UV-radiation on infectious disease antibodies, especially to cutaneous Human Papillomaviruses (HPV) to monitor exacerbations and impact on non-melanoma skin cancer risk. In the project, we will bundle the expertise from all Helmholtz Health Centers and jointly analyze and publish the data with a team of young investigators to build up expert knowledge.

Specific Aims

(1) Assignment of novel temperature / humidity / UV radiation data which cover temporal and spatial variation to
postal codes / residential addresses of 100.000 individuals of the NAKO and 3.000 individuals of the Rhineland
Study covering 19 different regions in Germany.
(2) Novel understanding of the underlying physiological responses in health with a focus on cardio-metabolic and
cancer outcomes, cognitive function, mental health and infectious disease burden.
(3) Quantification of interactions between impacts and future changes in adaptation due to complex causal
pathways and differential vulnerability associated with contextual and individual factors (aging, multi-morbidity,
urban vs. rural indicators).

Participating Centers:
▪ H. Vogel, M. Weitere, C. Künzer, M. Ließ

Aim of the project
The aim of project “Agricultural and Aquatic Systems” is to quantify the development of agricultural and aquatic
systems in response to climatic extremes in Germany. For different climate scenarios we deliver projections on
soil functioning, agriculture productivity, as well as on water quality of river ecosystems. We build upon recent
achievements in evaluating soil functions while separating soils’ potential and their actual state. The soils’
potential to fulfill various functions (productivity, C-sequestration, water storage and filtering) will be estimated
using newly developed rating functions based on spatial soil information, local patterns of land use and vegetation
anomalies obtained from DLR. The project will use land use patterns obtained from remote sensing to
characterize the management and dynamics of agricultural vegetation including anomalies related to drought
stress since 2000 for Germany. This, together with soil information, provides valuable input to generate damage
functions for estimating economic losses. For aquatic ecosystems, we will focus on the pressing problem of
eutrophication, which is considered a serious water quality problem worldwide (e.g. by the formation of toxic
cyanobacteria or instability in oxygen), which is directly linked to agricultural systems and which can be strongly
enhanced by climate change. As options for adaptation we will provide the required data for generating
development paths of agricultural systems under climate change including irrigation, nutrient regulation as well as
alternative cropping and tillage strategies. For aquatic systems, we will determine thresholds for pressures as
basis for the adaptation of aquatic ecosystems management under climate extremes. This generates
recommendations for acting aimed at decision makers, suggesting future land use and cropping practises under
scenarios of more frequently occuring droughts.

Participating Centers:
▪ A. Huth, I. Hajnsek

Aim of the project
Forests are a relevant ecosystem of the biosphere. They cover 30 percent of the land, store a huge amount of
carbon (in Germany ~ 1.000 mio. tons carbon) and they are an important part of the carbon and water cycle.

Forests deliver various resources (e.g. timber, biomass) and services (e.g. host of biodiversity, water retention,
soil erosion protection). However, climate changes - especially the droughts of 2003 and 2018 / 19 - strongly
affect the productivity of forest systems, turning some of them from a carbon sink to a carbon source. As trees are
long living (100 years and more), forest systems adapts quite slowly to a changing climate. Therefore, forestry is looking for management strategies, which can meet the required forest services in the next century.

Participating Centers:
▪ D. Thrän, C. Agert, Y. Scholz, R. Lehneis

Aim of the project

Renewable energies are subject to weather- and climate-induced changes. For the energy supply by ground-based, variable renewable energies (VRE), comprehensive information on the effects of extreme weather events on the power supply is need. The cooperation of UFZ and DLR in Project 9 is able to provide these. DLR will furthermore analyze the influence of weather on energy demand and its changes related to climate change and extreme events.

An important prerequisite for this project is high-resolution weather data for the study areas, which is, if necessary, supplemented by exemplary data from previous extreme weather events, like hailstorms or long periods of doldrums. UFZ develops simulation models with high technological detail to calculate hourly (or higher) electricity feed-in from VRE up to community level, using plant and weather data. Additionally, UFZ has detailed master data for onshore wind turbines and photovoltaic plants of any desired region in Germany. In Project 9, these models and datasets will be adapted for estimating the effects of extreme events on the power generation from VRE. Instead of feed-in data for Germany, DLR’s Energy Data Analysis Tool „EnDAT“ calculates future VRE potentials for whole Europe. It therefore has less technological detail than the UFZ models. In Project 9, the EnDAT potential analyses will be calibrated using UFZ feed-in time series for a past time period. In addition, high resolution analyses of power, heat and cooling demand in EnDAT allow quantifying effects of climate change and extreme weather events on energy demand in Germany and Europe. Project 9 collaborates with the scenario analysis of Project 1 (cluster Mitigation): Annual power demand and technology data for VRE potential analyses can be obtained from there, feed-in maps and information on full/peak load hours can be provided. The results and conclusions from Project 9 will also be usable in integrated energy system modelling and for research topics of social sciences so that they can be also connected to socio-political discussions.