EAR-Climate: Mountain Glacier Contribution to Sea Level CE 1900-2100

The area and mass of glaciers in mountainous regions have been shrinking dramatically in recent decades, and this accelerating glacier retreat impacts alpine systems and downstream communities dramatically around the globe. These shrinking mountain glaciers may also contribute to sea-level rise, yet the predictions of this influence are much less quantified than those for the polar ice sheets. Reasons for this include: (i) the large number of mountain glaciers and their individual complexities; (ii) modern satellite observations of glacier volume change are mostly limited to the last 20 years, which is not long enough to calibrate glacier dynamic models; (iii) the limitations in computing power to model glacier change for thousands of alpine glaciers and their impacts on the solid-earth response. The goals of the current project are to provide accurate predictions of mountain glacier melt rates across the globe together with the contribution to sea-level rise on the global and local scale, and to evaluate the impacts of glacier change on societies. The latter will include an assessment of risk for communities impacted by changing glaciers together with adaptation strategies such as migration. A documentary film will be prepared that narrates the journey of the glacial meltwater from its birth at the icy peaks of the high Andes all the way to the Pacific Ocean, in turn documenting the impacts on communities from the glacier to the ocean. The film will illustrate the process of building models for improved predictions of downstream effects of changing climate and will be available to a wide audience on web-streaming platforms.The accelerating mass loss of glaciers around the globe is impacting societies and contributing significantly to ongoing and accelerating sea-level rise. Initial estimates predict that mountain glaciers, which are highly sensitive to warming climate, might contribute up to half a meter to sea-level rise, but the uncertainties of these predictions remain considerably higher than those for the polar ice-sheets. This project will integrate glacier observations over the last century, and include them in a global glacier-change time-series. This time series will be developed by artificial intelligence methods, glaciologic modeling through CE 2100, solid earth modeling of isostatic adjustment related to mountain glacier change, and societal impact science that identifies areas of highest societal and economic costs, together with first-order solution strategies. The research will quantify to what degree mountain glacier changes since the end of the Little Ice Age (about CE 1850) are reflected in sea-level rise, and how these environmental changes affect densely populated regions down-stream of glaciated areas and near-shore communities. To achieve this goal, the project will use cutting-edge methodology, from new observations to artificial-intelligence-based modeling to societal impact science tools, that would be widely applicable to other problems at the interface of Earth Science and society.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.