Senior Researcher Sebastian Bjerregaard Simonsen from DTU Space has opened a digital replica of the Earth on the computer screen in front of him. He zooms in on Greenland and moves a slider with his mouse.
"Let's see what happens to the melting of the Greenland Ice Sheet and the resulting sea-level rise if we choose a scenario in which the global temperature increases by two degrees and we project this 50 years into the future," he says.
Moments later, several reddish areas along Greenland's coastline turn an even darker shade of red. The darker colour indicates that the ice is melting more rapidly before flowing into the ocean, contributing to rising global sea levels.
"This is exactly what we want to achieve with a Digital Twin of the Earth," says Sebastian Bjerregaard Simonsen, pointing to the prototype model on the screen showing Greenland and its melting ice masses.
The digital model of Greenland forms part of the major EU initiative Destination Earth (DestinE), which aims to develop a Digital Twin of the Earth based on artificial intelligence, advanced numerical models and vast amounts of observational data, including satellite measurements. A digital twin is a virtual representation of the Earth that enables researchers to test different climate scenarios and investigate their consequences before they occur in reality.
Sebastian Bjerregaard Simonsen leads the development of the Digital Twin for Ice Sheets, the component that integrates the Greenland and Antarctic ice sheets into the overall virtual representation of the Earth and also serves on the Strategic Advisory Board of the Destination Earth project.
"The idea is to build a global model capable of simulating a wide range of climate and environmental parameters based on observational data from satellites, monitoring networks and other data sources," he says.
The digital twin combines observational data, including satellite observations, with climate models, enabling researchers to simulate future scenarios and investigate the consequences of changes in the Greenland and Antarctic ice sheets.
The system consists of two main components: one model that estimates changes in the ice sheets based on satellite observations, and another model that translates these changes into projections of global sea-level rise.
DTU's contribution is well underway
The European Union aims to have a Digital Twin of the Earth's systems in place by 2030, enabling researchers, public authorities and decision-makers to simulate the impacts of climate change and explore different scenarios.
The goal is to provide a stronger scientific basis for climate adaptation and long-term planning, particularly in coastal regions.
"Our model incorporates large amounts of climate data, including thousands of satellite observations of the Greenland Ice Sheet collected over several decades. Based on these extensive datasets, we have developed a model that captures how the ice sheet has evolved over time. We also incorporate climate variables such as ocean and atmospheric temperatures," explains Sebastian Bjerregaard Simonsen.
"In the completed model, users will be able to simulate different scenarios: What happens in 50 years if global temperatures increase by two degrees? How much ice will Greenland lose? Where around the world will sea levels rise along the coast? The model will be able to answer these questions, while allowing users to adjust a wide range of other parameters".
The European Space Agency (ESA) is developing the platform on which the digital models will run and where users will interact with them. No one has ever attempted to build a digital replica of the entire Earth, making this an exceptionally ambitious project.
Sebastian Bjerregaard Simonsen and his colleagues have already made significant progress on their contribution to the project, which began in November 2024 and runs until November this year.
"We are making good progress. We are working on the sub-project that investigates the melting of the Greenland and Antarctic ice sheets and how this affects sea levels. Our goal is to deliver a pre-operational product featuring four demonstration cases: sea-level change, hydropower based on meltwater, improved melt models based on satellite observations, and analyses of Antarctic ice shelves and their future development," he explains.
"We expect to have the first version of our contribution ready by the end of this year, including the four demonstration cases".
A prestigious European initiative
With a budget of approximately DKK 3.8 billion, the digital twin is one of the European Union's large and prestigious climate research initiatives currently under way. DTU Space is just one of many European organisations contributing to the project.
The integrated model will represent the Earth's entire climate system. Among its many applications, it will help assess the effects of political measures on the climate. The model is driven by artificial intelligence and advanced computational models trained on large amounts of observational data. Satellite observations play a key role, but the system can also incorporate many other types of climate, environmental and socio-economic data.
"You can think of it as a set of Lego bricks, where each brick represents one component of the overall model. You can modify the individual components and combine them in different ways, creating a wide range of scenarios," says Sebastian Bjerregaard Simonsen.
The digital twin is dynamic and is continuously updated with both new observational data and improved AI models.
"We have very long observational time series, we understand the underlying physics, and we have extensive historical knowledge of climate conditions. This enables us to develop highly accurate models for carrying out 'what if' analyses".
Following air pollution in Portugal and placing hydropower in Greenland
The scope of the model is extensive. For example, satellite observations of temperature and air pollution in Portugal can be combined with information on hospital admissions and mortality, helping to predict pressure on healthcare systems during heatwaves.
Similarly, the digital models can support the planning of future coastal protection by estimating how high sea defences should be, while also helping the insurance sector assess climate-related risks.
The models can also analyse how meltwater and water resources will behave under different climate scenarios, including both the volume of water available and the direction in which it will flow. This knowledge could become particularly important in Greenland, where meltwater can be used for hydropower generation. It may help identify the most suitable locations and capacities for future hydropower plants.
"The really exciting part is when these models can be used directly to support decision-making, whether in healthcare, coastal protection, insurance or future energy supply. The vision is to provide researchers, public authorities, policymakers and local decision-makers with a system that allows them to test and understand the consequences of climate change and evaluate different solutions before they become reality," says Sebastian Bjerregaard Simonsen.
"We need to think in the long term because, although the melting of the ice sheets and the resulting sea-level rise occur gradually, the consequences could become severe if we fail to act in time".
