Destination Earth (DestinE) is a flagship initiative by the European Commission aimed at developing highly accurate digital replicas — or digital twins — of the Earth system to improve our ability to predict extreme weather events and to better understand and adapt to climate change. Building and operating these digital twins requires unprecedented computational performance, advanced numerical modelling, and strong collaboration between the weather, climate, and high-performance computing communities. This talk will present ongoing progress in the development and operation of the Weather-Induced Extremes and Climate Change Adaptation digital twins on Europe’s largest supercomputing infrastructures. It will cover the Digital Twin Engine, the underlying software infrastructure that enables the deployment and operation of the digital twins, as well as the practical challenges of scaling complex weather and climate models across diverse HPC architectures. Finally, the importance of well-designed workflows — both to ensure quality control and reliable execution of the digital twins, and to enable downstream applications to efficiently consume their data — will also be discussed.

We present the first digital twin framework that operationalizes the production of multi-decadal, global climate projections at kilometre-scale resolution, developed within the European Union’s Destination Earth initiative. Using three coupled Earth system models and selected impact-sector applications, we have built end-to-end workflows for both regular and on-demand climate projections on two EuroHPC supercomputers, LUMI and MareNostrum5. These workflows produced the first-ever multi-decadal simulations at 5 km resolution across all major Earth system components, using the same output parameters and grid, and achieving a production throughput of 0.6 simulated years per day and a climate data portfolio of 6.6 petabytes. We demonstrate the scalability of two of these Earth system models across both CPU and GPU-based systems at global resolutions up to 1 km, across atmosphere, ocean, land, and sea-ice, and report record-breaking full-machine performance on LUMI and MareNostrum5 of up to 97 simulated days per day at 1 km resolution.