Extreme heat is predicted to annihilate all mammals in 250 million years when the Earth’s continents merge to form one scorching, dry, inhospitable supercontinent according to one study.
The results of the first supercomputer climate models in the distant future demonstrate how tectonic motions would release massive amounts of carbon dioxide (CO2) into the atmosphere through volcanic eruptions, causing the sun to become brighter.
This is expected to warm the globe to the point where many mammals would be unable to survive, with only 8% to 16% of this future continent being viable.
Mammals, including humans, are better adapted to cold environments, with many species developing fur or hibernating. They are less tolerant of high temperatures.
Lead author Dr Alexander Farnsworth of the University of Bristol said: “The newly-emerged supercontinent would effectively create a triple whammy, comprising the continentality effect, hotter sun and more CO2 in the atmosphere, of increasing heat for much of the planet.”
“While we are predicting an uninhabitable planet in 250 million years, today we are already experiencing extreme heat that is detrimental to human health,” said Dr Eunice Lo, University of Bristol.
“The result is a mostly hostile environment devoid of food and water sources for mammals.
“Widespread temperatures of between 40C to 50C, and even greater daily extremes, compounded by high levels of humidity would ultimately seal our fate.
“Humans – along with many other species – would expire due to their inability to shed this heat through sweat, cooling their bodies.”
CO2 projections highlight the need to accelerate emissions reductions to combat rising temperatures
Scientists anticipate that CO2 levels will grow from roughly 400 parts per million (ppm) today to more than 600 ppm by the time the supercontinent Pangea Ultima forms.
However, this implies that people stop using fossil fuels – “otherwise, we will see those numbers much, much sooner,” said Professor Benjamin Mills, who estimated the study’s future CO2 forecasts.
The researchers, who published their findings in the journal Nature Geoscience, stated that their findings should not be interpreted as a relaxation of human efforts to combat climate change because rising temperatures are already harming people’s health.
Co-author Dr Eunice Lo of the University of Bristol said: “It is vitally important not to lose sight of our current climate crisis, which is a result of human emissions of greenhouse gases.”
“With the sun also anticipated to emit about 2.5% more radiation and the supercontinent being located primarily in the hot, humid tropics, much of the planet could be facing temperatures of between 40C to 70C,” said Dr Alexander Farnsworth, University of Bristol.
“While we are predicting an uninhabitable planet in 250 million years, today we are already experiencing extreme heat that is detrimental to human health. This is why it is crucial to reach net zero emissions as soon as possible.”
Scientists use advanced models to predict CO2 levels in a distant supercontinent scenario
To forecast future CO2 levels, the worldwide team of scientists simulated temperature, wind, rain, and humidity patterns for Pangea Ultima and used models of tectonic plate movement, ocean chemistry, and biology.
They also stated that when peering through space at other worlds potentially appropriate for humans, individuals should consider how continents are distributed, as being in a solar system’s habitable zone may still imply a planet is inhospitable.
Dr Farnsworth said: “The outlook in the distant future appears very bleak. Carbon dioxide levels could be double current levels.”