Analysing biodiversity shifts through a climate lens only, veils the full picture

An international group of scientists led by Pieter Sanczuk from Ghent University have revealed an important blind spot in how researchers worldwide study changes in the distributions of plants and animals. A new global study just published in Nature Climate Change shows that much research has a geographic set-up that facilitates the detection of poleward range shifts as expected under climate warming, though species range shifts are also shaped by multiple global changes, not climate change alone.

“A large part of what we think we know about species range shifts has been unintentionally shaped by the way studies are designed,” says Dr. Pieter Sanczuk (Forest & Nature Lab, Ghent University), lead author of the study. “If you only search along the south-north axis, you will of course mainly find movements in that direction.”

Why does this bias occur?

Countries that conduct a lot of climate research are often also elongated along the south-north axis (such as Finland, Sweden, or the UK). As a result, researchers more easily detect shifts in those directions, simply because of the shape of the investigated territories.

Shifts in other directions—such as westward or eastward—that are caused by other global changes such as nitrogen pollution can therefore remain undetected.

The researchers therefore developed a new metric, the Latitudinal Bias Index (LBI), which reveals and quantifies this geographic distortion. The index shows in which direction a study area is most likely to detect shifts—even before a single species is monitored.

What does this say about climate change?

The study confirms that species are shifting worldwide under the influence of climate change. But it also nuances this narrative. Poleward range shifts are only a part of the complex story. “In Europe, the redistribution of species toward the north is certainly not the only trend, and climate change is not the only cause. Other factors also play a role, such as nitrogen deposition, land-use change and intensification. As a result, species sometimes move in very different directions than just towards cooler areas,” Sanczuk says.

In the ocean, species follow temperature boundaries more closely, but even there, the shape of the study area plays a role.

Importance for nature management and policy

The findings are crucial for policymakers and land managers, who base decisions on predicted species range shifts.

“If we know that the current literature is mainly looking in one direction, then we need to broaden our perspective,” Sanczuk explains. “Otherwise, we miss the full picture. Changes in species distributions are not only driven by temperature alone.”

Bibliography

Global bias towards recording latitudinal range shifts. Pieter Sanczuk, Jonathan Lenoir, Pierre Denelle, Sabine B. Rumpf, Jeremy Borderieux, Costanza Geppert, Brunno F. Oliveira, Ingmar R. Staude. Nature Climate Change. Published online on 21 November, 10H00 (London time). Once online, available from: https://www.nature.com/articles/s41558-025-02498-5 Contact

Dr. Pieter Sanczuk Forest & Nature Lab, Universiteit Gent Pieter.Sanczuk@UGent.be

+32 (0)499 20 58 65