A “supercontinent” may make the Earth uninhabitable within 250 million years, according to what the study predicts | geology

A study has shown that the formation of a supercontinent on Earth could wipe out humans and any other mammals that still exist within 250 million years.

The mass extinction may have been caused primarily by heat stress as a result of greater volcanic activity that would put twice as much carbon dioxide into the atmosphere compared to current levels, an older sun that would emit more radiation and the extension of inland deserts into the tropics.

The supercontinent Pangea Ultima is expected to form when all existing continents merge together in the distant future. the The paper was published Monday in the journal Nature Geoscienceis the first attempt to model the extent of climate extremes from geological rearrangement.

Using the UK Met Office’s climate model and the University of Bristol’s supercomputer, the simulation also provided tectonic evidence for past extinction events and data that could be useful to astronomers searching for other habitable planets.

In the era of Pangea Ultima, extreme temperatures are expected to be dramatic, with more moisture than now along the coasts and extremely arid conditions in the vast interior deserts. In this world, global temperatures could rise by 15°C (and up to 30°C on Earth) above pre-industrial levels, which would return the world to the extreme heat last experienced in the Permian-Triassic. 260 million years ago, when more than 90% of species were extinct. Long periods of heat exceeding 40°C would be beyond the tolerance levels of many life forms.

Mammals have been the world’s great evolutionary success story, especially since the demise of the dinosaurs during the last great extinction event, but the ability of mammals to adapt to heat may be very slow. This includes humans who have been on Earth for a relatively short time.

Humans appeared about 6 million years ago when the world was a much colder place than it was during the time of the dinosaurs. Although our species has evolved remarkably quickly, we will face enormous challenges in the era of Pangea Ultima, assuming we survive the current self-induced climate crisis and mass extinction of other species.

In addition to the direct effects of heat, there will be severe problems with food supplies due to the collapse of vegetation. The paper notes that most plants become stressed at temperatures above 40°C and decompose completely if exposed to 60°C for prolonged periods.

The study’s lead author, Alexander Farnsworth, from the University of Bristol, said the prospect of another extinction event, involving humans, was a sobering reminder of extinction. “The Earth has a very variable environment. Humans are very lucky with what we have now and we should not push our climate beyond the cooler climate in which we evolved. We are the dominant species but the Earth and its climate decide how long that will last.” What comes next? Next is anyone’s guess. “The dominant species may be something entirely new.”

The authors acknowledge that their predictions have a high level of uncertainty due to the very long-term time frame, but they hope that the study, which began during the pandemic lockdown, will provide useful insights into past mass extinction events and the possibility of habitation by other organisms. Planets.

Until now, when astronomers scanned distant galaxies for planets that might provide alternative habitats for humans, they mainly took into account the distance from the nearest sun and the presence of water. The new study suggests that tectonics is also an important factor in determining the planet’s climate.

“If NASA could send a space shuttle to just one planet, I would choose a planet that does not have a supercontinent,” Farnsworth said. “It would be better to have multiple continents spread around, as there are now on Earth.”