We survived the 2012 "apocalypse," and researchers predict we might be around for a lot longer; at least 1.75 billion years to be exact.
Researchers looked at other far-off planets to estimate how long we can call Earth home, a University of East Anglia press release reported.
The team used the "habitable" zone concept to make their predictions, which is when the planet is at a distance from their parent star that could allow for liquid water on the surface.
"We used stellar evolution models to estimate the end of a planet's habitable lifetime by determining when it will no longer be in the habitable zone. We estimate that Earth will cease to be habitable somewhere between 1.75 and 3.25 billion years from now. After this point, Earth will be in the 'hot zone' of the sun, with temperatures so high that the seas would evaporate. We would see a catastrophic and terminal extinction event for all life," lead researcher Andrew Rushby, of UEA's school of Environmental Sciences, said.
This doesn't mean humans will make it through the last habitable seconds, most complex life will die off long before that and only microbes will exist on the barren planet. The human race will be drastically affected by even a minor temperature increase.
"Looking back a similar amount of time, we know that there was cellular life on earth. We had insects 400 million years ago, dinosaurs 300 million years ago and flowering plants 130 million years ago. Anatomically modern humans have only been around for the last 200,000 years - so you can see it takes a really long time for intelligent life to develop," Rushby said.
Rushby said studying habitability metrics could give researchers clues to how far intelligent life could go both on Earth and on alien planets.
"Of course, much of evolution is down to luck, so this isn't concrete, but we know that complex, intelligent species like humans could not emerge after only a few million years because it took us 75 per cent of the entire habitable lifetime of this planet to evolve. We think it will probably be a similar story elsewhere," Rushby said.
The team compared Earth to eight other planets that are believed to be in a "habitable phase." One planet called Gliese 581d had an impressive habitable lifetime of 42.4 to 54.7 billion years, which is "10 times the entire time that our solar system has existed."
"To date, no true Earth analogue planet has been detected. But it is possible that there will be a habitable, Earth-like planet within 10 light-years, which is very close in astronomical terms. However reaching it would take hundreds of thousands of years with our current technology," Rushby said.
Rushby said if humans are ever forced to move to another planet, Mars will be the most likely choice. While the Red Planet resembles a rocky desert wasteland, it has a habitable life that will last until the Sun dies in about six billion years.
