Glaciers around the world are retreating and thinning due to global warming; this directly impacts sea-level rise, streamflow and glacier related hazards. Results from numerical models that simulate the glacier changes into the future have shown that substantial glacier mass losses will continue throughout the 21st century, however, some of the processes affecting glaciers are represented in a rather simplified fashion or not considered at all in these models. Some of these processes lead to so-called feedbacks, i.e. effects that can amplify or reduce the immediate effects of climate change on glacier mass change. This project aims to investigate such feedbacks in detail and assess how, for example, glacier retreat, glacier instabilities and the mantle of debris cover often found on glacier tongues can influence how the glaciers react to climate change. The global glacier model PyGEM will be improved to better represent these processes and then used to study these feedbacks. Finally PyGEM will be used to project the mass and area changes of all 200,000 glaciers on Earth (outside the Greenland and Antarctic ice sheets) and their contribution to global sea level until the year 2100. These projections are important for coastal planers and policy-makers as well as communities affected by continued glacier mass loss. The project will be conducted in extensive collaboration with national and international partners.
Glaciers around the world are retreating in response to atmospheric warming with direct implications for sea-level rise, streamflow and glacier related hazards. Global-scale glacier model have projected continued substantial mass losses over the 21st century, however, relevant processes have been parameterized in a simplified fashion or ignored entirely in the current generation of these models. Some of these processes lead to non-linear feedbacks, i.e. amplify or diminish the effects of climate-induced glacier mass loss. GlacMod aims to explore such feedbacks in detail and investigate how glacier retreat, glacier surges and debris cover often found on glacier tongues affect the glacier response to climate change in global-scale glacier models. GlacMod will use the open-access global glacier model PyGEM and improve the model by coupling a physically-consistent iceberg calving model and accounting for debris cover. Dedicated model experiments when be conducted to quantify the role of feedback mechanism. Finally PyGEM will be used to project the mass and area changes and associated contributions to sea level of all 200,000 glaciers on Earth (outside the Greenland and Antarctic ice sheets) until the year 2100. These projections are relevant for coastal planers and policy-makers as well as communities affected by continued glacier decline. GlacMod will be performed in extensive collaboration with national and international partners.