Japan Geoscience Union Meeting 2025

Presentation information

[J] Oral

B (Biogeosciences ) » B-PT Paleontology

[B-PT04] Biotic History

Tue. May 27, 2025 9:00 AM - 10:30 AM Exhibition Hall Special Setting (4) (Exhibition Hall 7&8, Makuhari Messe)

convener:Isao Motoyama(Faculty of Science, Yamagata University), Takao Ubukata(Division of Geology & Mineralogy, Department of Earth & Planetary Sciences, Kyoto University), Kazuyoshi Moriya(Department of Earth Sciences, Faculty of Education and Integrated Arts and Sciences, Waseda University), Chairperson:Isao Motoyama(Faculty of Science, Yamagata University), Takao Ubukata(Division of Geology & Mineralogy, Department of Earth & Planetary Sciences, Kyoto University), Kazuyoshi Moriya(Department of Earth Sciences, Faculty of Education and Integrated Arts and Sciences, Waseda University)

10:15 AM - 10:30 AM

[BPT04-06] The future diversity and lifespan of metazoans governed by global warming

*Kunio Kaiho1 (1.Tohoku University)

Keywords:Future, mass extinctions, global warming, metazoans

The diversification of metazoans, ranging from cnidarians to vertebrates, began approximately 0.7–0.5 billion years ago and has been shaped by evolutionary innovations and five major mass extinctions. These animals are predicted to become uninhabitable due to global warming caused by increasing solar luminosity approximately 1.0–1.1 billion years from now. However, previous calculations did not account for icehouse-greenhouse cycles, abrupt climate changes triggered by volcanic activity and meteorite impacts, or geographic and ecological differences. This study incorporates these additional factors and predicts that surface-dwelling and shallow-water metazoans will go extinct around 0.7 billion years from now—300–400 million years earlier than previously estimated. Some subterranean and deep-sea lineages may survive, but they are expected to be completely eradicated during a mass extinction event approximately 1.0–1.1 billion years from now. To mitigate biodiversity loss, advanced species may need to adapt to subterranean habitats or consider extraterrestrial migration, such as colonization of Mars, before 0.7 billion years from now. For the first time, it has been revealed that humanity is at the midpoint of the lifespan of surface-dwelling metazoans. The time has come to consider our actions based on this new reality.