Extreme temperatures in future may potentially lead to the first mass extinction on Earth since the dinosaurs, a new study has revealed.
The study in Nature Geoscience, led by Dr Alexander Farnsworth, Senior Research Associate at the University of Bristol, explores the impact of a future supercontinent and other climatic shifts.
The study predicts that Earth's continents will eventually merge into one landmass, called the "Pangea Ultima". This supercontinent may dramatically alter Earth's climate, creating conditions too hot and arid for most life forms to survive.
By utilising supercomputer climate models, the team showed how this configuration might create a planet largely inhospitable for humans. "The newly-emerged supercontinent would effectively create a triple whammy, comprising the continentality effect, hotter sun, and more carbon dioxide in the atmosphere, of increasing heat for much of the planet," Dr Farnsworth explained.
Dr Farnsworth's "triple whammy" outlines how these three factors could contribute to unbearable temperatures:
Continentality Effect: As land moves away from cooling ocean effects, temperatures on the supercontinent would soar.
A Brighter Sun: Over millions of years, the sun will emit more energy, gradually warming the Earth.
Increased carbon dioxide: Volcanic activity from tectonic shifts would release higher amounts of carbon dioxide, intensifying heat retention in the atmosphere.
The combination, Dr Farnsworth warns, may lead to temperatures between 40 degree C to 50 degree C (104 degree F to 122 degree F), with even higher daily extremes and humidity. "Humans - along with many other species - would perish due to their inability to shed this heat through sweat," he said.
The study indicates that only 8 percent to 16 percent of Pangea Ultima is likely to be suitable for mammals. Most of the landmass may face extreme heat and dryness and sourcing food and water may become a significant survival challenge.
Although this scenario is millions of years away, the researchers stress the urgency of addressing today's climate crisis. "It is vitally important not to lose sight of our current climate crisis, which is a result of human emissions of greenhouse gases," said Dr Eunice Lo, a Research Fellow in Climate Change and Health at the University of Bristol.
"While we are predicting an uninhabitable planet in 250 million years, today we are already experiencing extreme heat that is detrimental to human health. This is why it is crucial to reach net-zero emissions as soon as possible."
To forecast carbon dioxide levels, the research team studied tectonic movements and ocean chemistry. They estimate that carbon dioxide concentrations could rise from around 400 parts per million (ppm) today to over 600 ppm in the distant future.
