Who will survive climate change?

This image shows two fossilized specimens of the mollusk genus Myophoria from the fossil collections of the Museum für Naturkunde, which became extinct at the end of the Triassic period during a major global warming event.
This image shows two fossilized specimens of the mollusk genus Myophoria from the fossil collections of the Museum für Naturkunde, which became extinct at the end of the Triassic period during a major global warming event. (Image: Carola Radke, MfN)

Researchers investigate mass extinction events with rapid global warming in the Earth’s history

Researchers from the Museum für Naturkunde in Berlin and FAU have investigated extinction events with rapid global warming in the last 300 million years. They discovered that species from warm and cold waters are highly likely to become extinct as a consequence of global warming, while species in temperate waters survive.

“Fossils from the Earth’s history are the only direct proof of which species are under most threat from rapid global warming,” says lead author Dr. Carl Reddin from the Museum für Naturkunde in Berlin and visiting scientist at FAU. “One advantage of investigating fossil records is that we can study the influence of global warming without all the other human influences such as overfishing or pollution,” explains co-author Martin Aberhan, also from the Museum für Naturkunde in Berlin. “This demonstrates the relevance of research collections for current and future predictions.”

Carl Reddin and Martin Aberhan from the Museum für Naturkunde in Berlin and fellow researchers from FAU aimed to identify the shared geographic patterns of extinction across seven rapid global warming events from the past 300 million years. The most well known of these was the near-apocalyptic mass extinction event at the end of the Permian period. The authors compared the extinction patterns from these events with usual extinction patterns to find out which responses from species might be unique to global warming. They discovered that species from warm and cold waters are highly likely to become extinct as a consequence of global warming, while species in temperate waters survive.

To find out the cause, the researchers set up a simulated spherical Earth with a natural temperature gradient from the tropics to the poles. Two oceanic areas emerged in which species drastically lost habitat in their preferred temperatures: in the tropics, where the area of suitable habitat shrank considerably, and at the poles, where habitat disappeared completely. The similarity between the simulated and fossil patterns was striking. While the largest numbers of species are lost from the species-rich warm waters of the tropics, cold-water species have the greatest risk of extinction as sustained warming destroys their habitat.

Where did species live during this time?

The researchers traced the animals’ former habitat using models of plate tectonics, which describe how the continents move and how oceans grow or disappear through time. Then the researchers added data from paleoclimate models and estimated seawater temperatures at those locations where the animals once lived. In this way, the researchers were able to distinguish, for example, between animals that once preferred cold waters and those that preferred warm waters.

Other teams of researchers have already identified certain events in geological history as being rapid global warming events, such as the mass extinction at the end of the Permian and Triassic periods, the less well known Carnian pluvial episode, three phases during the Jurassic and Cretaceous periods and the Paleocene Eocene thermal maximum around 55 million years ago. Finally, the points in time during which species became extinct allowed the researchers to investigate extinction patterns related to their temperature preferences during these warming events and to compare the patterns with times without global warming.

Published in: Carl J. Reddin, Martin Aberhan, Nussaibah B. Raja & Ádám T. Kocsis 2022. Global warming generates predictable extinctions of warm- and cold-water marine benthic invertebrates via thermal habitat loss. Global Change Biology

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