The End Is... Near? All Life On Earth Will End In One Billion Years

All animals and plants will vanish from the Earth within the next
billion years, a new study suggests. Ironically, Armageddon is going
to arrive as a result of too little, rather than too much, carbon
dioxide in the atmosphere.


Currently, experts are trying to find ways to cut levels of the
greenhouse gas to prevent global warming running out of control.


But as the Sun ages and grows hotter, greater evaporation and chemical
reactions with rainwater will take away more and more carbon dioxide.
In less than a billion years, its levels will be too low for
photosynthesising plants to survive, say scientists. When that
happens, life as we know it on Earth will cease to exist. With the
loss of plants, herbivorous animals will also dieout, as well as the
carnivores that prey on them.


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 hostileto life by this point,' said
astrobiologist Jack O'Malley-James, from the University of St Andrews
in Scotland.


'All living things require liquid water, soany 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 basedon a computer simulation of the impactlong-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. Theincreasingly intense
radiation will cause the Earth to heat up to such an extent that the
oceans start to evaporate.


The research may also have implicationsfor 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 tell-tale 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 mostlikely to survive to determine what types of gases they
would release to the atmosphere.


'By the point at which all life disappearsfrom the planet, we're left
with a nitrogen/carbon-dioxide atmosphere with methane being the only
sign of active life.'