Illustration of the formation of Pangea, the supercontinent that united almost the entire land surface, 290 million years ago.
Photo: NASA
In their study, paleoclimatologist Alexander Farnsworth and his colleagues present the first climate model of the distant future created using a supercomputer. They simulated the trends in temperature, wind, rain and humidity that will prevail as Earth’s continents merge to form the next supercontinent, Pangea Ultima.
Therefore, according to their model, the formation of Pangea Ultima will lead to volcanic eruptions associated with more frequent movements of tectonic plates, which will lead to a sharp increase in carbon dioxide (CO2) in the atmosphere.
Representation of the layout of the landmass in 250 million years.
Photo: Wikipedia
In addition, solar radiation will increase by 2.5%, which will affect the surface temperature of the supercontinent, whose land will be located mainly in the warm tropical zones.
Result: Pangea Ultima will be an extremely hot supercontinent, with only 8 to 16% of the surface habitable for mammals.
The arrival of Pangea Ultima will trigger a triple shock that includes the continental effect, a hotter sun and more CO2 in the atmosphere, notes Alexander Farnsworthde.
Average temperatures between 40 and 70 degrees Celsius and even higher daily extremes, coupled with high humidity, will mean the demise of humans and mammals, which will become extinct due to their inability to lose heat through transpiration. A quote from Alexander Farnsworth, University of Bristol
In fact, prolonged periods of heat above 40°C exceed the tolerance thresholds of many life forms, including the vast majority of plant species. This reality will create an environment devoid of food and water sources for mammals.
Vegetation will be rare on the surface of Pangea Ultima.
Photo: iStock
Sightseeing features
- The Earth formed 4.6 billion years ago (at the same time as the solar system);
- Over the course of Earth’s evolution, several supercontinents emerged: Rodinia, Columbia, Pannotia and Pangea.
- The planet has already experienced periods of intense heat. The last one dates back to the Permian-Triassic era, 260 million years ago, when more than 90% of species were wiped out (new window).
- Since the first traces of fossil life on Earth, species have experienced five major extinction crises in which more than 75% of them disappeared.
- The last mass extinction occurred about 66 million years ago, when an asteroid hit Earth, killing the dinosaurs and most life on the planet.
- In recent decades, Earth has experienced the sixth major extinction event in its history.
The human mammal
The first hominids, the ancestors of humans, appeared about 7 million years ago, which is relatively recent in the evolution of the Earth. At that time the planet was much colder than at the time of the dinosaurs.
In fact, throughout evolution, mammals have survived due to their ability to adapt to extreme weather conditions, especially cold weather (fur and hibernation).
Although they have evolved to better withstand the cold, mammals’ tolerance to high temperatures has remained fairly constant.
Although our species has evolved remarkably quickly, we will face enormous challenges in the Pangea Ultima era… If we can overcome the current climate crisis of our own making, mass extinctions of other species will follow. A quote from Alexander Farnsworth, University of Bristol
Gray areas
It is not hidden from the authors of the work that their gloomy forecasts are accompanied by great uncertainty, as they relate to at least the distant future.
Regardless, for Alexander Farnsworth, this study still represents a stark reminder of the transience of Earth’s climatic conditions.
The earth’s environment is very changeable. So far, people have been very lucky. “If we are the dominant species, we must not forget that it is the planet and its climate that determine the duration of this dominance,” reminds Alexander Farnsworth in a press release.
In another world
Humanity’s search for habitable exoplanets is often linked to the distance to a star and the presence of water. This study also highlights the importance of plate tectonics and continental configuration in this research.
Although Earth will still be in the habitable zone in 250 million years, the formation of a supercontinent with high CO2 levels will make most of the planet uninhabitable for mammals, the researchers note.
Therefore, in their opinion, the configuration of the continental mass of an exoplanet is also a key factor in whether it is habitable for humans.
One supercontinent, multiple scenarios
In addition to Pangea Proxima, other scenarios – and other names – have been proposed in recent years to project the Earth’s surface into the future. According to some, Amasia will form in 200 to 300 million years as the Pacific Ocean closes (new window).