Supercontinent Pangea Ultima: Future Threat to Mammalian Life
Scientists predict that extreme heat resulting from the formation of a future supercontinent, dubbed Pangea Ultima, could ultimately lead to the extinction of mammals, including humans. This long-term climate modeling isn’t science fiction, but a projection based on tectonic movement, solar radiation and carbon dioxide levels.
The Formation of Pangea Ultima
Research published in the journal Nature Geoscience, led by Dr. Alexander Farnsworth of the University of Bristol, projects that Pangea Ultima will form approximately 250 million years from now.1 The merging of continents will result in vast inland areas being far removed from the moderating influence of oceans, creating a “continentality effect” that intensifies heat.
Triple Threat to Habitability
Dr. Farnsworth explains that the supercontinent will create a “triple whammy”: continentality effects, a hotter Sun, and increased CO2 levels.1 These factors combined could raise temperatures across much of the planet, potentially reaching 40–50°C (104–122°F) or higher, with humidity levels making it impossible for mammals to cool themselves through sweating.
Increased Solar Radiation and CO2 Levels
Climate models indicate that solar radiation will increase by around 2.5 percent compared to present levels, while volcanic activity could push CO2 levels beyond 600 parts per million (ppm).1 This combination could raise land temperatures to a range of 40 to 70°C (104–158°F), a lethal range for most mammals.
Challenges for Mammalian Survival
Prolonged exposure to extreme heat poses a significant challenge for mammals, as their bodies rely on sweat evaporation for cooling. The study estimates that only 8 to 16 percent of the land area on the future supercontinent will remain within physiologically tolerable limits.1 Widespread drought and shrinking vegetation will exacerbate the situation, leading to scarcity of water and food, and potential collapse of terrestrial ecosystems.
Relevance to the Current Climate Crisis
While this scenario unfolds on a geological timescale, researchers emphasize its relevance to the current climate crisis. Dr. Eunice Lo, co-author of the study from the University of Bristol, notes that the planet is already experiencing extreme heat endangering human health.1
A Unique Extinction Event
Earth’s history includes five major mass extinction events, including the one that wiped out the dinosaurs 66 million years ago. However, if the Pangea Ultima projection proves accurate, the resulting extinction due to extreme global heat could be the first primarily triggered by the combined effects of solar evolution, plate tectonics, and greenhouse gas accumulation.
Implications for Exoplanet Habitability
This research too impacts how scientists assess the habitability of planets outside our solar system. A planet within the “habitable zone” may not be truly life-friendly if its continental configuration leads to extreme warming, as projected for Pangea Ultima.
Urgent Need for Emissions Reduction
Researchers stress that while the threat is distant, the modern climate crisis is an immediate concern. Failure to reduce greenhouse gas emissions could accelerate the projected extreme conditions, bringing them closer to human civilization.
1 Farnsworth, A., et al. “Future heat stress on land under extreme CO2 and solar forcing.” Nature Geoscience 17, 148–154 (2024). https://doi.org/10.1038/s41561-023-01218-8