Earth is currently thought to be in the middle of a supercontinent cycle as its present-day continents drift. The last supercontinent, Pangaea, broke apart about 200 million years ago. The next, dubbed Pangaea Ultima, is expected to form at the equator in about 250 million years, as the Atlantic Ocean shrinks and a merged Afro-Eurasian continent crashes into the Americas.
Regions in the middle of the supercontinent, far from the oceans, would turn into deserts that are unliveable “expect for very specialized mammals”, says Farnsworth. The lack of moisture would also diminish the amount of silica that is washed into the oceans, which usually removes CO2 from the atmosphere.
Increased solar radiation will cause further heating. The Sun is predicted to be 2.5% more luminous at the time of Pangaea Ultima’s formation, a result of the star having burnt more of its hydrogen fuel and shrunk its core, increasing its rate of nuclear fusion.
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This would lead to a mass extinction, says [researcher Alexander] Farnsworth. “It wouldn’t just be for mammals. It could be for plant life, as well, and other types of life. What comes out of it is anyone’s [guess]. In other mass extinctions a new species tends to dominate.”
