In 250 million years the seven continents of the Earth will no longer exist. What remains will be a vast supercontinent, called Pangea Ultima, where the scorching conditions will cause the extinction of mammal life.
This forecast is the result of scientific research published in the journal Nature Geoscience. The scientists ran computer simulations to advance the positions of continents forward in time, before realising the cataclysmic implications of their prediction.
The climate forecast for Pangea Ultima shows temperatures regularly exceeding 60C. The huge land mass will settle on the equator and its great size will lead to extreme weather — a supercharged version of the continental climate in present-day Chicago or Volgograd.
Bouts of volcanic activity, caused by the clash of continents, will push temperatures higher. The sun, which will become brighter with age, will provide additional heating.
All of this will be too much for the mammals. The changes will happen over a geologically short time of ten million years, which will outpace evolution.
“Mammals have, in the past, only been able to increase their [temperature] limit by 0.6C per million years. That makes it very difficult evolutionarily, once you get extreme temperatures going above these physiological limits,” Dr Alexander Farnsworth of Bristol University said. “This will be a very inhospitable world where the weather, as well as the climate, is not your friend.”
Continental drift, the slow movement of land masses, is nothing new. The interlocking pattern between South America and Africa is just one piece of evidence of the former supercontinent Pangea, which broke apart at the start of the Jurassic period.
Like weather forecasting but bigger
Looking forward 250 million years, the researchers have prepared their best guess how a reformed Pangea Ultima would look. Using their simulation of the new supercontinent, scientists used computer-modelling techniques that are similar to weather forecasting.
The researchers also simulate complex carbon-capture effects, including the response to the climate by plankton and algae in the future oceans.
The research has implications for the search for extraterrestrial life on exoplanets — planets beyond our solar system. Typically, astronomers search for life in the “Goldilocks zone” around distant stars which are considered habitable regions: not too hot, not too cold.
The authors suggest astrophysicists may have to expand the zone. Reconfiguration of continents can render a planet more or less habitable by raising the temperatures or changing the climate patterns. Planets that previously would have been ruled out as habitable could actually have suitable conditions to host life.
“Our current understanding of habitability is in its very infancy and the distribution of land masses is an important factor in defining habitable regions,” said Ingo Waldmann, professor of astrophysics at University College London (UCL).
“With the James Webb Space Telescope and the advent of 30m telescopes such as the ELT [Extremely Large Telescope], we are, for the first time, able to start investigating all the intricate effects that led to life in the Milky Way”.
Some uncertainty in the predictions for Pangea Ultima stems from the computer simulation of the resting place of the future supercontinent. Rearranging the existing continents into a different supercontinent could alter some of the climate predictions.
The effect of evolution over 250 million years means that our descendants certainly will not be human, assuming humans have descendants. Farnsworth is eager to warn of the more serious, and immediate, human-caused climate risk.
“The rate of change at the present day is incredibly dangerous, we have never seen such a rate of change in the geological past,” said Farnsworth, the lead author of the study, “We are creating our own problems that can accelerate our own extinction.”
