The researchers also accounted for continentality,which refers to the greater temperature range in the interior of continents compared to the coast,and the fact Pangea Ultima would form along the tropics and contain vast deserts.

The result conjures a vision of a sun-scorched supercontinent,inhospitable to mammalian life – even for those critters that burrow or shelter in caves.

Said Alexander Farnsworth,senior research associate at the University of Bristol and lead author of the paper:“Widespread temperatures of between 40 and 50 degrees,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.”

Humans and other mammals are imperilled if temperatures remain above 40 degrees for days on end.

Wet-bulb temperatures,which include the sapping effect of humidity,above 35 degrees can kill in six hours (parts of the Middle East,Asia and the Americas have approached andmay exceed this deadly threshold in coming years due to climate change).

The authors write mammals might evolve to adapt to these extremes but note the upper limit of their heat tolerance hasn’t budged much in millions of years of evolution.

There are alternative interpretations of what the supercontinent might look like,but the authors say most of them would have a similar climate to Pangea Ultima.

The exception is Amasia,a duelling supercontinent theorybacked by some Australian scientists.

Professor Dietmar Muller,a plate tectonics expert from the University of Sydney who wasn’t involved in the study,said Amasia would be more hospitable than the parched Pangea Ultima.

“A supercontinent at higher latitudes would not have the same effect[as Pangea Ultima] at all – temperatures would be more moderate.”

But Muller agrees with the authors’ point that tectonic movement is key to keeping Earth in the so-called “Goldilocks zone”,where water is available and life is possible.

“Plate tectonics play an extremely important role in helping drive the evolution of life on Earth and creating a habitable climate,” Muller said.

The authors also wrote in theirNature Geoscience paper that cosmic explorers should consider the arrangement of a planet’s continents,not just its distance from a sun,in future expeditions aimed at finding exoplanets that could sustain human life.

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