The intensity and frequency of weather extremes are increasing due to climate change. Records are being broken and society is increasingly feeling the impact of a warmer world. However, human-induced warming increases the chances of experiencing not only single extreme weather events but also situations where multiple hazards occur simultaneously or after each other.

Human activities versus natural variability

Climate change attribution allows to quantify the contribution of human activities versus natural variability to the observed extreme events and their impacts. A clear statement about how climate change is contributing to the impacts of recent weather extremes can promote societal preparedness and awareness. COMPASS will lay the scientific foundation for the operational deployment of an EU climate attribution service that will be implemented by Copernicus.

“Climate change is already increasing the frequency and severity of extreme weather events, such as storms, heatwaves and droughts. Such events can have devastating societal impacts, and it is becoming increasingly clear that the most impactful disasters are often the result of a complex interplay of multiple physical and societal drivers.” says Sanne Muis, who is the coordinator of COMPASS.

I am very excited to start working on this scientifically challenging and societally relevant topic. It is great to collaborate with world-leading institutes in this relatively new scientific field

Sanne Muis

Innovative approach

COMPASS will innovate by going from the attribution of single-driver extremes to the attribution of more complex extremes (including compounding, sequential and cascading hazard events) and enabling a shift from a hazard-centred analysis to an impact-centred perspective. We will develop new methods including a multi-scale approach to model hazards and societal impacts, weather type analysis to better understanding the physical drivers that give rise compound extremes, and contextualized storylines to communicate attribution results. Deltares will focus on water-related hazards and develop an automated workflow that uses a combination of the Delft3D Flexible Mesh, SIFNCS and Wflow software.

Use cases

The framework will be validated and applied to a set of use cases that cover complex extremes for various hazard types and impact contexts. These use cases include:

  • compound flooding due to tropical cyclones in 2019 and 2022 in Mozambique (Deltares)
  • sequential tropical cyclones in the Caribbean in 2020 (Red Cross Red Crescent Climate Centre)
  • multiple storms in 2013/14 and drought combined with a heatwave in 2022 in the United Kingdom (Met Office)
  • compound flooding and storm in France during cyclone Xynthia in 2010 (PIK)
  • an operational system for heatwaves and drought in Poland (Szczecin University)

A second set of use cases will be defined during phase II of the project.

The COMPASS project is funded by the EU Research and Innovation Programme, Horizon Europe, and will run until 2027.


The COMPASS consortium consists of Deltares (Netherlands), MetOffice (UK), Potsdam Institute for Climate Impact Research (PIK), University of Szczecin (Poland), Red Cross Red Crescent Climate Centre (Netherlands), and SEVEN (Greece).

The project officially kicks off on 5 and 6 February 2024, when the consortium members meet in Delft.

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