Humans will be extinct on Earth within 250 million years, but that’s if we stopped burning fossil fuels right now, a grim new study reveals.
Computer simulations suggest our planet will face a mass extinction that will wipe out all mammals, report experts from the University of Bristol.
Any life forms still alive on Earth at that time would have to contend with temperatures between 104°F and 158°F (40°C and 70°C), they say.
But their calculations don’t take into account greenhouse gases emitted from burning fossil fuels and other man-made sources, so the date of our demise will likely be even earlier.
It would be the first mass extinction since the dinosaurs went extinct about 66 million years ago, when Earth was catastrophically hit by a huge space rock.
Extreme heat is likely to wipe out humans and mammals in the distant future, even without the influence of CO2-emitting fossil fuels (artist’s impression)
The new study was led by Dr Alexander Farnsworth, Senior Research Associate at the University of Bristol’s School of Geographical Sciences.
“The outlook for the distant future looks very bleak,” Dr. Farnsworth said.
‘Carbon dioxide levels could double current levels.
“Humans – like many other species – would die due to their inability to eliminate this heat through sweat, cooling their bodies.”
According to researchers, within 250 million years, all of Earth’s continents will have joined together to form a supercontinent known as Pangea Ultima.
Earth’s land would be donut-shaped with an inland sea in the middle: all that remains of the once-mighty Atlantic Ocean.
Meanwhile, the surrounding Pacific Ocean would occupy most of the Earth’s surface.
Pangea Ultima is just a possible projection of what Earth’s supercontinent could look like once the tectonic plates come together.
Whatever the exact alignment, scientists are confident that Earth’s continents will slowly merge to form a hot, dry and largely uninhabitable mass.
The image shows the geography of Earth today (left) and the expected geography of Earth in 250 million years, when all continents converge into one supercontinent (Pangea Ultima).
The image shows the average temperature of the warmest month (degrees Celsius) for Earth and the projected supercontinent (Pangea Ultima) in 250 million years, when it would be difficult for almost any mammal to survive.
Tectonic processes in the Earth’s crust would also lead to more frequent volcanic eruptions, which produce huge releases of carbon dioxide (CO2) into the atmosphere, further warming the planet.
Another form of global warming that is less known involves the sun’s natural glow, which will make the planets increasingly hotter.
“The newly emerged supercontinent would effectively create a triple whammy, made up of the continentality effect, a hotter sun and more CO2 in the atmosphere, causing increased heat across much of the planet,” Dr Farnsworth said.
«The result is a largely hostile environment, devoid of food and water sources for mammals.
“Widespread temperatures of between 40 and 50 degrees Celsius, and even higher daily temperature extremes, combined with high levels of humidity, would ultimately seal our fate.”
For the study, scientists used computer climate models to simulate Pangea Ultima’s temperature, wind, rainfall and humidity trends.
To estimate the future level of CO2, the team used models of plate tectonic movement, ocean chemistry, and more to map the inputs and outputs of CO2.
The researchers emphasize that they did not take into account the contribution of CO2 emissions from the burning of fossil fuels, commonly cited as the main cause of climate change today.
Pictured, monthly average air temperature at Earth’s surface 250 million years in the future if all continents join together to form Pangea Ultima.
The new calculations do not take into account greenhouse gases emitted by burning fossil fuels and other man-made sources: the date we become extinct will probably be even earlier (file photo)
They estimated that CO2 could rise from around 400 parts per million (ppm) today to more than 600 ppm many millions of years in the future.
“Of course, this assumes that humans will stop burning fossil fuels, otherwise we will see those numbers much, much sooner,” said study co-author Professor Benjamin Mills of the University of Leeds.
The findings indicate that only 8 to 16 percent of the earth would be habitable for mammals, but all mammal species will likely be wiped out.
To make matters worse, the supercontinent would be located primarily in the hot, humid tropics, so much of the planet could face higher temperatures than many mammal species are accustomed to.
“We cannot predict how long humans will exist; however, if we assume we last that long, that future world would be inhospitable to us,” Dr Farnsworth told MailOnline.
The academic said we could survive if we built “environmentally controlled shelters with air conditioning.”
“But we would probably also have to build other facilities to house food production,” he said.
Another hope for humanity is the formation of civilizations on other planets in other solar systems, but at the moment this is just the stuff of science fiction.
‘[Survival] “It will all depend on whether we can escape this planet and, if not, whether we have the ability to use geoengineering solutions to manage the climate,” Dr Farnsworth said.
The study was published today in Nature Geoscience.
