Media release

From: Springer Nature

Next supercontinent formation could lead to inhospitable climate for mammals

Hot climatic conditions during the formation of the next supercontinent in around 250 million years may surpass the physiological limitations of mammals, according to a modelling study published in Nature Geoscience.

Mammals, including humans, have strategies to avoid excessive heat. However, temperatures exceeding 40 °C for extended periods of time can cause mortality for many mammal species, with humidity making this heat stress more acute. Ongoing anthropogenic climate change is likely to cause this physiological limit to be reached in some locations, though most of the planet will remain habitable for mammals even in extreme warming scenarios. The next supercontinent, which some scientists have termed Pangea Ultima, is predicted to form in around 250 million years when all current continents merge into one landmass. The impact of this formation on mammal species is unclear.

Alex Farnsworth and colleagues use a climate model that simulates temperature and humidity patterns to predict that mammalian heat stress limits will be exceeded across the future supercontinent. They suggest elevated atmospheric carbon dioxide levels could be twice that of current levels, contributing to higher temperatures, as a result of volcanic gas emissions. They note the location of the supercontinent (primarily in the tropics) exacerbates this heat and that the Sun will also emit about 2.5% more radiation by this point in the future. The authors indicate this could leave only 8% of land habitable for mammals, leading to an elevated extinction risk as populations shrink and become disconnected.

The authors note that their predictions are uncertain, with alternative future supercontinent configurations potentially altering the results. They also highlight that other evolutionary or human-related processes could cause mammal extinctions prior to supercontinent assembly.