02/07/2013 03:03 BST | Updated 02/07/2013 05:20 BST

Earth A Billion Years In The Future Will Be Arid, Hot And Deadly To Humanity

The whole world is doomed.

As the sun gets hotter, greater evaporation and chemical reactions with rainwater will take away more and more carbon dioxide.

This means all plants are going to die. There will be too little CO2 for them to photosynthesise.


Scientists believe as the Sun heats up, much of the Earth will come to resemble the landscape of the Upper Geyser Basin region in Yellowstone National Park in Wyoming

With no plants all the herbivores will die.

Then there will be no food for the carnivores - including us.

Our species is going to die out on an arid planet so dry there aren't any oceans.

Cheerfully, we have a billion years before this happens, plenty of time to take that holiday, learn a language or tell that cute shop assistant you really fancy them.

For your great-great-great-etc grandchildren however, the future is grim.

Eventually microbes will be all that remains - and for the majority of them even their days will be numbered.

After another billion years, the oceans will have dried out completely leaving only the hardiest bugs.

"The far-future Earth will be very hostile to life by this point," said astrobiologist Jack O'Malley-James, from the University of St Andrews in Scotland.

"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 underground."

The surviving organisms would also have to cope with extreme high temperatures and intense ultraviolet radiation, he said.

Mr O'Malley-James made his bleak forecast at the National Astronomy Meeting taking place at the University of St Andrews.

The predictions are based on a computer simulation of the impact long-term changes to the Sun are likely to have on Earth.

As the Sun ages over the next billion years or so, it is expected to remain stable but to grow steadily brighter. The increasingly intense radiation will cause the Earth to heat up to such an extent that the oceans start to evaporate.

The research may have implications for the search for extra-terrestrial life, according to Mr O'Malley-James.

"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," he said. "Life in the Earth's far future will be very different to this, which means, to detect life like this on other planets we need to search for a whole new set of clues.

"We have now simulated a dying biosphere composed of populations of the species that are most likely to survive to determine what types of gases they would release to the atmosphere. 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".