University of Bremen & Alfred Wegener Institute







University of Bremen

Environmental Physics - MARUM

Lectures - Supervision of Students - PhD Students - Projects Uni


Section Paleoclimate Dynamics at AWI

Team - Tools - Research - Projects


Gerrit Lohmann

Publications - CV - Research - Affiliations







Paleoclimate dynamics contextualizes past, present and future changes, quantifies natural variability, and informs us about mechanisms under different forcings. An important method is comparison of models and data (out-of-sample assessment, emergent constraints).

“Looking at the past sharpens our understanding of possible future climate changes.”

It is critical to understand the extent to which increasing human population and industrialization have already caused significant changes in the Earth’s climate. To properly answer this question, quantitative information is needed on the magnitude and rate of natural variations in the oceans, continents, and cryosphere. The best way to determine the magnitude of past changes is to examine historical time series of direct temperature measurements. Information on the pre-anthropogenic state of the system can be obtained either from proxies that record past climate and environmental conditions, or by simulating climate with comprehensive models under external forcing. On the other hand, we want to look into the possible future by analyzing the past. This is important for climate warming, associated thresholds, tipping points, and extremes.

We focus on Earth system modeling, paleoclimate variability, and theoretical aspects of Earth system analysis. Particular aspects include the role of global ocean circulation, including interactions with the cryosphere, and dynamical interpretation of paleoclimate data mainly from high latitudes like ice cores and marine sediments. Analysis of those and models allows assessment of forcing and feedback mechanisms for climate change. In turn, model simulations can help interpret the causes of observed variations in paleoclimate data, e.g., through the use of isotopes. We develop and use state-of-the-art models to quantify the feedbacks in the atmosphere-ocean-ice system and to inform us about the full range of climate variability.

With our holistic approach, we seek to overcome the subjective perceptions and biases (“the blind man and the elephant”) that hinder the scientific process. It is important to strive to understand the world as objectively as possible. A holistic approach means looking at something as a whole, interrelated entity: Paleoclimate Dynamics is about understanding the big picture, from the deep past to the long-term future, bridging disciplines, and thinking outside the box.

When it comes to climate, there is no plan B because there is no planet B. Follow the Carbon dioxyde in the atmosphere.











Author: G. Lohmann, Universität Bremen, 28359 Bremen