An astrobiologist is predicting the end of Earth will be in approximately 2.8 billion years. The end of the world will not be the result of humanity but due to the sun as it grows and becomes hotter.

Jack O'Malley James, an astrobiologist from the University of St. Andrews in Scotland, believes the sun’s growth over the next 2.8 billion years will heat up Earth to the point that the oceans will evaporate. O’Malley-James created computer models of the change in temperature over the next few billion years to map out the gradual end of Earth and life on the planet’s surface. O’Malley-James’ research will be presented at the 2013 National Astronomy Meeting of the Royal Astronomical Society.

According to O’Malley-James’ calculations, plants and animals will begin to disappear within the next billion years. As temperatures increase, the evaporation process will begin leading the depletion of carbon dioxide in Earth’s atmosphere. The lack of CO2 will cause the disappearance of animals and planets. As CO2 levels decrease, the amount of oxygen on Earth will slowly diminish with the oceans slowly evaporating away. The trio of negative environmental consequences due to the sun’s growth will make Earth uninhabitable. O’Malley-James said in a statement, “The far-future Earth will be very hostile to life by this point.”

Because of the harsh conditions on the surface on Earth, life may be reduced to microbes surviving in limited environments. “All living things require liquid water, so any remaining life will be restricted to pockets of liquid water, perhaps at cooler, higher altitudes or in caves or underground,” O’Malley-James said. The climate simulation is not just meant to determine doomsday for Earth but aid in researchers’ attempts to discover life on alien planets.

The current search for life on alien planets relies on looking for evidence that’s present in a thriving world, much like present-day Earth, such as oxygen or ozone. “When we think about what to look for in the search for life beyond Earth, our thoughts are largely constrained by life as we know it today, which leaves behind telltale fingerprints in our atmosphere like oxygen and ozone,” O’Malley-James said. Using the simulation, researchers can determine what microbes can survive such harsh conditions and determine what gases that make up the atmosphere would signal life is present. O’Malley-James said, “By the point at which all life disappears from the planet, we're left with a nitrogen/carbon-dioxide atmosphere with methane being the only sign of active life.”