This project will bring Dr. Ben Marzeion from the University of Bremen to the Department of Geosciences at the University of Oslo to collaborate on a research project on investigating anthropogenic versus natural causes in past global glacier mass loss. Glaciers have contributed more to sea-level rise than either of the ice sheets in the 20th century and are projected to contribute as much as or more than the ice sheets in the 21st century. Glacier wastage due to climate change also directly impacts freshwater availability and contributes to geohazards in many regions. Understanding the causes and mechanisms of glacier change is therefore directly relevant for assessing the impact of glacier-related environmental change and its associated impacts on society.
Disentangling the relative influence of anthropogenic and natural forcing on glacier mass loss is a major challenge: a first estimate of the anthropogenic contribution to global scale glacier mass loss indicated an unambiguous and dominant anthropogenic contribution to glacier melt in the late 20th and early 21st centuries, but also found that since 1850, only roughly one quarter of the global mass loss could be attributed to anthropogenic climate forcing. However, using another method, it was found that essentially 100 % of glacier mass loss since 1850 is anthropogenic. This strongly conflicting evidence severely limits the confidence in our understanding of one of the most impactful aspects of climate change.
In this project, we will combine the different methodological approaches to come to a consensus estimate of the anthropogenic fraction of global glacier mass loss since 1850.
In addition, the research stay will foster collaboration, scientific exchange and interaction between both university´s global glacier modeling groups.