Umeå University Researchers Reveal How Global ‘Über-Lake’ Model Transforms Understanding of Freshwater and Climate Links

Umeå University Researchers Reveal How Global ‘Über-Lake’ Model Transforms Understanding of Freshwater and Climate Links

(IN BRIEF) Researchers from Umeå University, together with international partners, have developed a novel framework that treats the world’s millions of lakes as a single composite “Über-lake,” enabling the discovery of emergent patterns that individual studies cannot capture. Using global datasets on depth, shape, and climate, and applying high-performance computing, the team built models that integrate lakes’ physical characteristics and ecological functions. Central to the approach is lake hypsography, which determines how lakes mix, store heat, and cycle nutrients. The study finds that lakes as a whole resemble land more than oceans, with most surface area being shallow, shaping their ecological and climatic roles. This new perspective offers powerful insights into how freshwater systems collectively influence climate change and ecological stability.

(PRESS RELEASE) UMEÁ, 12-Aug-2025 — /EuropaWire/ — Umeå University researchers, in collaboration with international colleagues, have unveiled a groundbreaking way of understanding the role of lakes in the Earth’s climate system by treating the world’s millions of lakes as one unified “Über-lake.” This innovative approach, published in Nature Water, aggregates global lake data to reveal patterns and properties that cannot be seen when studying lakes individually. By doing so, scientists can now better understand how freshwater systems collectively influence and respond to climate change.

The study integrates vast datasets on lake depth, shape, and climate from across the globe, processed using high-performance computing. This enabled the creation of composite models – the so-called Über-lakes – that combine the physical characteristics and functions of lakes on a global, regional, and climate-zone basis. At the core of this method lies lake hypsography, the measurement of how a lake’s surface area changes with depth, which governs how lakes store heat, mix water layers, exchange gases, and cycle nutrients.

“Our work shows that, when considered as a composite, lakes reveal emergent patterns that give us deeper insight into how freshwater ecosystems contribute to Earth’s resilience,” says Cristian Gudasz, researcher at the Department of Ecology, Environment and Geoscience at Umeå University and first author of the study.

One striking finding is that, in terms of their overall structure, the world’s lakes resemble land far more than oceans. While oceans are dominated by deep waters, most global lake surface area is shallow, which significantly affects their ecological and climatic impact. The models also uncover how lakes in cold, glaciated regions differ in structure and function from those in warmer climates.

The Über-lake concept bridges the gap between the complexities of individual lakes and the large-scale patterns that emerge when they are studied collectively. This opens new possibilities for understanding not only how lakes respond to environmental change, but also how they influence climate feedback loops and ecological stability.

“This work gives us a powerful new lens to explore the relationship between freshwater systems and climate. It’s more than the sum of individual lakes – together, they act as a global system that affects climate dynamics in profound ways,” Gudasz adds.

The study, A comprehensive framework for integrating lake hypsography and function on a global scale, was authored by Cristian Gudasz, Dominic Vachon, and Yves T. Prairie, and published in Nature Water on July 17, 2025.

Media Contact:

Cristian Gudasz
Research fellow
cristian.gudasz@umu.se
+46 90 786 95 83

SOURCE: Umeå University