Extreme temperatures, radiation and collapse of food supply created by merging of continents would cause mass extinction
The formation of a supercontinent on Earth could wipe out humans and any other mammals that are still around in 250m years, according to a study.
The mass extinction would be caused primarily by heat stress as a result of greater volcanic activity that would put twice as much carbon dioxide into the atmosphere as current levels, an older sun that would emit more radiation and the extent of inland deserts in the tropics.