A simple, physically motivated model of sea-level contributions from the Greenland ice sheet in response to temperature changes

Sea level could rise by several meters over the next centuries. The Greenland ice sheet could be an important contributor to future sea-level rise, because of its large volume and its high sensitivity to surface air temperature increases. Frameworks for the integrated climate risk management often require fast, simplified treatments of sea-level rise, in particular for estimating the risks associated with low probabilities but potentially high impacts. State-of-the-art ice sheet models provide important insights, but are often computationally too demanding to evaluate tail-area risks. Here we present SIMPLE, a physically motivated model of the Greenland ice sheet in response to temperature changes. SIMPLE can skillfully reproduce the results from a three-dimensional ice sheet model and outperforms existing simple models, after similar calibration. We anticipate that SIMPLE will be calibrated to other ice sheet models and can provide a fast approximation (emulator) for such models in studies that require many model evaluations. SIMPLE is a fast physically motivated model of the Greenland ice sheet.It provides fast approximations in studies that require many model evaluations.It skillfully reproduces 3D ice sheet model simulations over a wide range of forcings.SIMPLE outperforms existing simplified representations, after similar calibration.