Mammals are halfway through their era on this planet. We’ve existed about 250 million years since mammals evolved on earth and we only have another 250 million left before most of the world is no longer habitable.
A study recently published in Nature Geoscience explained that the world is only a couple hundred million years away from creating a new supercontinent. Researchers used data on continental movements to create a new future map. The scientists also used information about what chemical fluctuations in the atmosphere will look like in the future to create a range of different atmospheric and geological conditions on what they’re calling Pangea Ultima. Remember learning about Pangea in middle school, the supercontinent that formed over 300 million years ago? Pangea Ultima is version 2.0. The reunion of all the continents clustered together again would create an environment so harsh, that it would stop mammals from thriving.
In this future scenario, about 8% to 16% of the large continent will be habitable for mammals, the study outlined. Most of this will be found in the northern edges of Pangea Ultima and a small part of the southern end. Before the industrial era and emissions began to increase global temperatures, about 66% of the landmass on this planet was habitable for mammals, the study explained.
“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,” Alexander Farnsworth, senior research associate at the University of Bristol and study author, explained in an online statement. “The result is a mostly hostile environment devoid of food and water sources for mammals.”
Mammals have reigned on this planet due to being able to adapt to warm and cold environments, but most mammals aren’t made to live in extremely hot environments for long periods of time. Humans in particular sweat as a way to naturally cool our bodies down, but there is such a thing as a too-hot world where our bodies’ natural mechanisms won’t work. This is because tectonic movements would create more volcanic eruptions in the future, spewing more carbon dioxide into the atmosphere which will trap more heat on the planet.
“We think CO2 could rise from around 400 parts per million (ppm) today to more than 600 ppm many millions of years in the future,” Eunice Lo, a research fellow in climate change and health at the University of Bristol and study author, said. “Of course, this assumes that humans will stop burning fossil fuels, otherwise we will see those numbers much, much sooner.”
The sun is also expected to become hotter and stronger a few hundred million years in the future. Around 200 million years from now, researchers estimated that the sun is likely to emit about 2.5% more radiation. “Widespread temperatures of between 40 to 50 degrees Celsius, and even greater daily extremes, compounded by high levels of humidity would ultimately seal our fate,” Farnsworth said. Most mammals and future humans (if our species is still around) will expire in what could be permanent 100 degrees Fahrenheit heat.
This means that Pangea Ultima’s coasts are likely to be even more humid than our coastal regions are today, and the vast inland will turn into a large desert. This will lower the planet’s ability to provide enough vegetation for a steady food supply for any human civilization that exists that far out into the future, and for other mammals.
Though this scenario is well into the future, our planet is currently stressing society and animal environments. Climate change caused by burning fossil fuels has warmed our ambient air temperatures at unnaturally fast rates in the last few decades. Without the formation of a supercontinent, or radiation from a stronger sun, the world has experienced its hottest summer in the Northern Hemisphere, and an alarmingly hot start to spring in Australia.
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