Articles | Volume 23, issue 3
https://doi.org/10.5194/bg-23-1199-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-23-1199-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Future diversity and lifespan of metazoans under global warming and oxygen depletion
Department of Earth Science, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan
Related authors
Kunio Kaiho
Biogeosciences, 19, 3369–3380, https://doi.org/10.5194/bg-19-3369-2022, https://doi.org/10.5194/bg-19-3369-2022, 2022
Short summary
Short summary
I found a good correlation between the mass extinction magnitudes of animals and surface temperature anomalies. The relation is good regardless of the difference between warming and cooling. Marine animals are more likely than tetrapods to become extinct under a habitat temperature anomaly. The extinction magnitudes are marked by abrupt global surface temperature anomalies and coincidental environmental changes associated with abrupt high-energy input by volcanism and impact.
Kunio Kaiho
Biogeosciences, 19, 3369–3380, https://doi.org/10.5194/bg-19-3369-2022, https://doi.org/10.5194/bg-19-3369-2022, 2022
Short summary
Short summary
I found a good correlation between the mass extinction magnitudes of animals and surface temperature anomalies. The relation is good regardless of the difference between warming and cooling. Marine animals are more likely than tetrapods to become extinct under a habitat temperature anomaly. The extinction magnitudes are marked by abrupt global surface temperature anomalies and coincidental environmental changes associated with abrupt high-energy input by volcanism and impact.
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Co-editor-in-chief
Kaiho uses historic records of diversification, starting with the early evolution of metazoans from cnidarian ancestors 700-500 mya, to predict the future of metazoan life on Earth. In analyzing past records of diversification, environmental drivers beyond the typically considered meteorite impacts and volcanism, such as variations in solar irradiance and inherent climatic fluctuations, are included as major additional drivers. These analyses lead to the proposal that metazoan life will likely go extinct on Earth within the next 700 million years. This extinction will be driven by long-term increases in physiological stress resulting from warming due to increasing solar radiation, as well as decreasing O2 and increasing CO2 concentrations in Earth’s atmosphere. While gradual changes in the Earth system will likely cause a decline in metazoan prevalence, the final thrust to extinction will likely require a global-scale geological or astronomical event.
Kaiho uses historic records of diversification, starting with the early evolution of metazoans...
Short summary
Life on Earth has changed over millions of years, shaped by shifting climates and natural disasters. This study explores how future environmental changes—like rising temperatures and reduced oxygen—may gradually reduce animal diversity on land and in the oceans. It predicts most complex animals could disappear in about 0.9 to 1 billion years, offering new insights into the far future of life on Earth.
Life on Earth has changed over millions of years, shaped by shifting climates and natural...
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