Abrupt Climate Changes

Lecturers: Stefan Mulitza, André Paul


This course focuses on the reconstruction and modeling of abrupt climate change. Students are introduced to the evidence for rapid climate fluctuations (e. g. the so-called Younger Dryas, Heinrich and Dansgaard-Oeschger events) from ice and marine sediment core data. Conceptual climate models are used throughout the course to investigate the processes that cause abrupt climate change. Concepts of nonlinear dynamics such as multiple steady states and hysteresis are developed, and the responsible feedbacks (e.g. the ice-albedo and vegetation-climate feedbacks) studied. The role of the thermohaline circulation is assessed. Finally, the prospects of abrupt climate change in the future are discussed. Software tools employed are programs such as Excel, Grapher and MATLAB programs.


The students can describe the processes that are fundamental to abrupt climate change. Furthermore, they are equipped to analyze proxy data and compare them to the results of numerical climate models using MATLAB as the basic software tool.


As part of the module exam "Climate Change II: Models and Data"


oral exam


Committee on Abrupt Climate Change (Richard B. Alley, Chair), Abrupt Climate Change. Inevitable Surprises. National Academy Press, Washington D. C., 2003. Further reading is provided during each individual lecture/exercise.