Overheating

• One of these – the Permo-Triassic mass extinction event – led to the demise of roughly 90% of Earth’s species.
• Most of these events have coincided with the formation of a supercontinent, where Earth’s tectonic plates slowly come together and combine.
• Scientists predict that Earth’s continents will again merge together in 250 million years to form a supercontinent called “Pangea Ultima”.

It’s going to get hot

• The primary reason behind this temperature rise is the projected location of Pangea Ultima, which would be centred on the equator.
• Our estimates also indicate that when Pangea Ultima eventually forms, the Sun will be 2.5% brighter than its present state.
• If we consider daily maximum temperatures and extreme weather events, then temperatures could potentially be pushed above 60℃ in some regions.

Inhospitable conditions

• For instance, humans cool themselves down during hot weather by sweating, while dogs rely on panting to dissipate heat.
• Prolonged exposure to such conditions can result in heatstroke, potentially causing swelling in critical organs like the brain.
• North American moose, for example, have a critical wet-bulb temperature threshold of 17℃ under calm conditions or 24℃ if it is windy.

Do mammals stand a chance?

• Second, during the PETM, the continents were positioned in a way that allowed mammals to move more easily towards cooler regions near the poles to escape extreme heat.
• This will make it challenging for mammals to travel long distances in search of cooler areas.
• What life form will become dominant if mammals do perish is anyone’s guess.