Climate change can also trigger abrupt and unexpected shifts in the Earth system. Such climate surprises occur when key parts of the climate system, called tipping elements, respond in sudden and nonlinear ways to relatively small changes in conditions. Prominent tipping elements include the Greenland and Antarctic ice sheets and the Atlantic Meridional Overturning Circulation (AMOC), a large-scale ocean circulation that strongly influences regional and global climate.
If destabilized, these tipping elements could lead to dramatic and irreversible changes, such as rapid sea-level rise or large-scale disruptions of weather patterns. Understanding the risk of such events is critical for societies worldwide, but current scientific methods struggle to provide reliable forecasts on the long timescales—centuries to millennia—over which these processes unfold. As a result, projections of future climate change carry deep uncertainties about the likelihood, timing, and consequences of tipping events.
FORCLIMA addresses this challenge by developing innovative tools to robustly forecast climate surprises. Its aim is to advance our ability to anticipate abrupt climate shifts, reduce uncertainty in long-term projections, and improve our understanding of interactions between different tipping elements. FORCLIMA takes a twofold approach that moves well beyond the current state of the art. First, it relies on a new generation Fast Earth System Model (FESM) called CLIMBER-X. This model integrates the most up-to-date understanding of ice sheets, ocean circulation, and atmosphere–ocean–ice interactions. CLIMBER-X is fast enough to run very large ensembles of simulations, which are essential to assess the full range of possible futures and to capture low-probability, high-impact events. Second, a novel probabilistic framework will be developed within the project. To ensure realism, the new model will be constrained with results from the latest ESMs and observational datasets. This probabilistic approach will allow FORCLIMA to generate forecasts that account for uncertainty in key processes while remaining consistent with the best available science.
FORCLIMA will provide the first probabilistic forecasts of major climate surprises on multi-centennial to millennial timescales. It will also deepen our understanding of the risks of ice-sheet collapse and AMOC weakening or shutdown, and their potential combined effects on sea level, climate stability, and ecosystems. Moreover, it will deliver tools that can be used by the broader climate science community to explore uncertainties in Earth system projections. Finally, it will contribute critical knowledge for climate risk assessments, supporting policymakers and stakeholders in preparing for low-probability but high-impact events.
In a broader sense, FORCLIMA will strengthen Europe’s position at the forefront of climate science by providing unparalleled insight into the long-term impacts of climate change. By addressing one of the most profound scientific and societal challenges of our time—the possibility of abrupt and irreversible climate tipping—the project will help societies better anticipate and prepare for the climate of the future.
