Experts from around the world gathered in Hamburg, Germany, from 20–24 July for the km-Scale Global Modelling Summit 2026 to assess progress in global kilometre-scale modelling and consider the next steps for the field. ECMWF scientists Peter Düben, Sebastian Milinski, Matthias Aengenheyster and Luise Schulte joined experts in Earth-system modelling, observations, high-performance computing and artificial intelligence to assess progress in global kilometre-scale modelling at the summit, which was led by the WarmWorld project and partners and locally organised by the Max Planck Institute for Meteorology.

Discussions at the summit explored some of the key questions shaping the future of Earth-system modelling: How can growing high-performance computing (HPC) capabilities make global kilometre-scale simulations more efficient? How can artificial intelligence accelerate climate research? What atmospheric and oceanic processes are represented more explicitly at kilometre scales? And how can increasingly detailed simulations help us better understand extreme events, climate change and their impacts on society?

These questions are closely connected to ECMWF’s activities, including in the framework of the European Commission’s Destination Earth (DestinE) initiative. Through DestinE, ECMWF works with more than 120 partner organisations across Europe to implement the Climate Change Adaptation Digital Twin (Climate DT), the Weather-Induced Extremes Digital Twin (Extremes DT) and the Digital Twin Engine that enables them to run on EuroHPC systems as well as a range of AI activities.

ECMWF’s contribution to the summit also included a presentation by Peter Düben, Head of Earth System Modelling at ECMWF, on the meaning and role of resolution in Earth-system modelling. Together with ECMWF scientists Sebastian Milinski, Matthias Aengenheyster, Luise Schulte as well as presenters from DestinE partner organisations, they contributed to wider discussions on the scientific and technological developments needed to advance global high-resolution modelling. 

Exploring climate futures at kilometre scale 

One focus of the summit was how high-resolution global simulations can improve our understanding of climate change and its impacts, including extreme events. 

Thomas Jung from the Alfred Wegener Institute (AWI) presented work on global climate storylines, an approach that is being applied in DestinE’s Climate DT to explore how extreme events could unfold under different climate conditions. 

The Climate DT is implemented by a broad European partnership led by CSC – IT Center for Science, working in close collaboration with ECMWF. It provides globally consistent high-resolution climate and impact-sector information and supports multi-decadal projections and “what-if” storylines at spatial scales where many climate impacts and extreme events are experienced.  
 
A new generation of Climate Digital Twin simulations was released through the Destination Earth Platform in May. The release includes global multi-decadal simulations covering 1990–2049 and storyline simulations exploring how extreme events observed between 2017 and 2025 could unfold under different climate conditions. The simulations are accompanied by tailored information for sectors including hydrology, wind energy, wildfires and extreme precipitation.

These simulations complement established international climate-modelling activities such as CMIP and CORDEX by adding globally consistent kilometre-scale information and helping connect global climate projections with the scales at which many climate impacts and extremes are experienced. Work is continuing to evaluate and contextualise the simulations alongside observations, reanalyses, CMIP6 and CORDEX datasets. The Climate Digital Twin also featured in presentations from Francisco Doblas-Reyes (BSC) on the operationalisation of climate projections and Jenni Kontkanen (CSC-IT) on the path from km-scale modelling to operational Earth System Digital Twins.  

Simulating extreme weather in unprecedented detail

The Extremes DT complements this climate information with high-resolution simulations of extreme weather events. Its global component is developed and run regularly by ECMWF, while its regional component is implemented by a partnership led by Météo-France, involving 32 institutions in more than 20 countries, including many national meteorological services. The regional component can zoom in on extreme events over Europe at sub-kilometre resolution.  
 
The Extremes Digital Twin complements information and capabilities available at national and European level, supporting national authorities and meteorological services in their roles in preparing for and responding to the consequences of extreme events.  

Connecting research, computing and operational expertise 

Such simulations require exceptional computing capacity. The Destination Earth Digital Twins rely on access to EuroHPC systems, while ECMWF’s wider forecasting and Earth-system modelling activities rely on its own dedicated operational 24/7 supercomputing infrastructure which enables ECMWF to produce and disseminate operational global numerical weather predictions from days to seasons ahead to its Member and Co-operating States and beyond.
 
Access to the EuroHPC computing infrastructures enables DestinE to test new model configurations, produce multi-decadal climate simulations and kilometre-scale simulations of extreme events, and move scientific advances from research into sustained operational delivery. 

The discussions in Hamburg highlighted many of the challenges shaping the next generation of Earth-system modelling: how to make better use of rapidly evolving HPC technologies, how artificial intelligence can accelerate climate research, how simulations and observations can be used more synergetically, and how increasingly detailed models can improve our understanding of extreme events and their impacts in a changing climate. 

Through DestinE, many of these aspects are already being brought together. By combining European expertise in Earth-system science, European high-performance computing and operational prediction, ECMWF and its partners are helping move advanced digital twins from cutting-edge research towards sustained capabilities for understanding climate change and extreme weather.