Joint Seminar: Arctic Amplification: Role of effective heat capacity and response to CO2 and aerosol forcings
Arctic Amplification (AA) is a phenomenon characterized by enhanced near-surface air temperature changes over the Arctic compared to lower latitudes. It is a paramount feature of observed climate change in recent decades, and it is also evident in reconstructions of past climate changes throughout Earth’s history. In this talk, I will present evidence that recently observed AA is a fundamental consequence of the Arctic’s lower effective heat capacity compared to lower latitudes, which causes the Arctic to warm up faster as atmospheric CO2 increases. The AA response to CO2 emissions mitigation will also be discussed. I will present modeling evidence showing that delayed mitigation could trigger a collapse of the Atlantic Meridional Overturning Circulation, leading to abrupt Arctic-amplified cooling and sea-ice expansion. Finally, the AA response to CO2 forcing will be compared with the response to anthropogenic aerosol forcing. I will show that increasing aerosol emissions produces stronger AA than increasing CO2 emissions, and will argue that this reflects a more general tendency for AA to be stronger in response to negative climate forcings.
Date
06.05.2026
Time
13:30 h
Place
- Bundesstr. 53, room 022/023
- Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg