May 7, 2018: FB1 Seminar

11:00, Lecture Hall, Düsternbrooker Weg 20

Melting glaciers have become icons of anthropogenic climate change. Their strong mass loss, most likely the biggest contributor to sea-level rise during the 20th century - and often documented in impressive picture comparisons - seems to unequivocally demonstrate the human interference with the climate system. However, glaciers respond to climate change with a lag. Observed glacier change is therefore often the result of climate change preceding the time of observation many decades, or even centuries. Using formal detection and attribution methods, we show that only about 30 % of the global glacier mass loss since 1850 is attributable to anthropogenic forcing. Within the 20th century, this anthropogenic fraction increased almost linearly, reaching about 70 % in the past two decades. The imbalance of glacier mass with concurrent climate conditions implies a strong commitment to further mass loss in the future. We show that even without any additional greenhouse gas emissions, glaciers would eventually lose about one third of their present day mass and thus remain an important contributor to sea-level rise. Any additional emission will increase the committed glacier mass loss at a rate of 15 kg of ice per kg of CO₂ emitted.

List of all FB1 seminars