Anna von der Heydt appointed Professor of Paleoclimate Dynamics
How the climate from prehistoric times improves climate models

Only about a century and a half ago did we begin measuring the climate, yet the Earth carries a far longer record of heatwaves, ice ages, and warming periods. What can that past teach us about the future? Anna von der Heydt, newly appointed Professor of Paleoclimate Dynamics at Utrecht ľϸӰ, uses climate models to explore that question. Information from ancient soil layers, fossils, and ice cores helps her refine those models and make more reliable predictions.
“In the past, there were periods much warmer than today,” says Anna von der Heydt. “By looking at what happened then, we can learn what may lie ahead.” If such warm periods can be successfully simulated with models, it gives confidence that they can also represent the future realistically.
Proxies
That sounds easier than it is. Direct climate records only go back to around 1850. For everything before that, scientists rely on so-called proxies: indirect indicators of, for example, temperature or CO₂ levels in a given era. These can come from oxygen isotope measurements in ice cores, tiny fossil shells in sediment layers, or the location of ancient tree lines.
Ice cores and fossils
To reconstruct what the climate looked like millions of years ago, Von der Heydt works closely together with geoscientists. They collect traces from the past and map proxies by studying, for instance, polar ice cores and fossils. “They provide the data; I try to reconstruct the climate with models,” she explains. She then compares the models with evidence from these natural archives. “That way we can test whether the models are a good representation of reality, and whether they’re suitable for predicting the future climate.”
Working together with geoscientists is important. They provide the data, I try to reconstruct the climate with models
This interdisciplinary collaboration is essential, though not always easy. “Reconstructing a single ice core can take years, and that core tells you something about one specific spot. A climate model, on the other hand, tries to capture global temperature. So you need ways to connect those very different sources of information.”
Tipping points
Another important part of her work focuses on feedbacks and tipping points in the climate system—mechanisms where small changes can trigger large effects. “With a Vici grant I set up a research group dedicated to this,” she says. “Now I want to link that knowledge more closely to paleoclimate research.”
In the classroom
Alongside her research, Von der Heydt teaches both bachelor’s and master’s students. She lectures on topics such as fluid dynamics, about how air and ocean currents work, to students of physics and geosciences. “That interdisciplinary mix is fun but also challenging,” she says. “Not everyone starts with the same background knowledge.” Still, she hopes to spark her students’ curiosity for climate research. “And I want them to keep a sense of wonder about how the climate system works. We don’t all need to become climate scientists, but a basic understanding is important, especially now.”
I hope students continue to marvel at how the climate system works
Much to gain
In the coming years, Von der Heydt aims above all to strengthen connections. Between data and climate models, of course, but also between different disciplines, and between science and society. “We have much to gain from working together more closely and learning each other’s language. If we succeed, we’ll be able to tell the climate story of the future more clearly.”
A complex story
Communicating climate research results to the outside world can be tricky. “You need a lot of nuance when it comes to climate change. On the one hand, you don’t want to spread panic, but you also shouldn’t downplay the results,” says Von der Heydt. “As scientists we have a responsibility to communicate clearly about climate change, including its uncertainties.” She sees this as both a challenge and a learning process. “How do you explain a complex story about risks and tipping points without oversimplifying or dramatizing it? That’s something we really need to learn.”
First female professor
With her appointment, Von der Heydt takes on not just a scientific role but also a symbolic one: she is the first female professor at IMAU. “I only realized it when people pointed it out to me,” she says with a smile. “But it’s true. And I do think it’s important to highlight visibility and diversity in the natural sciences.” She has long been involved in initiatives such as WomenNETPhysics, which work toward a more inclusive academic environment.