National Geographic Daily News
A coronal mass ejection is captured using different light wavelengths.

Our life-giving sun, seen here shooting off a coronal mass ejection, will snuff out Earth's remaining life forms in about 2.8 billion years from now.

Image courtesy SDO/NASA

Andrew Fazekas

for National Geographic

Published October 28, 2013

The final days of life on Earth will come some 2.8 billion years from now, suggests a sobering new study.

Currently at a comfortable temperature for life on Earth, our aging sun will slowly warm over its lifetime. Within about five billion years, the sun will exhaust its nuclear fuel and bloat into a "red giant" star that may even engulf our planet.

Things will get toasty for existing life-forms long before that red giant stage is reached. The question examined by a team led by astrobiologist Jack O'Malley-James, of the University of St. Andrews in Scotland, is: When will things get too hot for life to continue?

Using measures such as temperature and abundance of water and food to examine the future health of Earth's biosphere, the scientists have mapped out how all life may begin to die off.

They also analyzed what Earth's "biosignature" might look like to a distant alien civilization searching for life. The study has been accepted for publication by the International Journal of Astrobiology and released recently on the physics archive maintained by the Cornell University Library.

Plants Go First

The team's long-range weather forecast for the far future shows that as temperatures on Earth begin to slowly rise, more water vapor will form, resulting in the steady removal of carbon dioxide from the atmosphere.

Plants rely on carbon dioxide to generate energy through photosynthesis, so the complete removal of CO2 would be bad news for foliage. The first hints of the death of life on Earth, the study found, will come in 500 million years, when less-hardy species of plants begin to die off as global carbon dioxide levels drop.

As more plant species go extinct, so will the animals that rely on them as a source of food and oxygen.

"When plant numbers decline, these two commodities become increasingly scarce, resulting in the simultaneous end of animals over the next billion years alongside the end of plants," the study says.

Only Microbes Left

By about 2.8 billion years from now, only hardy communities of microbes will be left behind to inherit the Earth.

But as the Earth continues to relentlessly warm, oceans will evaporate, triggering a runaway greenhouse effect, which will lead to rapid further heating of the planet and a very scarce supply of liquid water.

"Only the hardiest microbes will be able to cope with this, until even they can no longer survive when temperatures cross the threshold at which DNA breaks down—around 140°C [284°F]," added O'Malley-James.

Signs of Life

The team hopes that these findings may help our own search for life beyond Earth, by expanding the number of potential signatures of life to look for when we learn to analyze planetary atmospheres in more detail.

"A planet in a later stage of its habitable development may appear uninhabited if we only look for the signs of life as we know it on Earth today," said O'Malley-James.

"Knowing what other potential signatures life could have could help us make a positive detection of life on a planet that may previously have been ignored."

Always Look on the Bright Side

While this model points to a gloomy future for our planet, O'Malley-James and colleagues think that their timeline for future life is probably a conservative one. There are still a lot of unknowns when it comes to predicting what life will do under duress, said O'Malley-James.

"It is difficult, if not impossible, to predict what evolutionary tricks life may have up its sleeve to cope with these future extreme environmental changes," he said.

But the study no doubt shows that life on Earth is naturally quite resilient to change. If the past is any indication, we can take heart: Despite major environmental upheavals and mass extinctions, life has never been entirely snuffed out since it emerged.

"While it is depressing to know that life will end one day, there is still plenty of comfort in the fact that it won't happen for an unimaginably long period of time," O'Malley-James said.

Follow Andrew Fazekas, the Night Sky Guy, on Twitter and Facebook.

65 comments
Anne H
Anne H

This is really interesting.  I majored in geology in college and thoroughly enjoyed it.  Good thing science and religion aren't incompatible.  I wouldn't like it either if I thought all life was going to end at some point.

Shawn Goldtooth
Shawn Goldtooth

humans with their greed and selfishness will make earth uninhabitable long before that....we are our own worse enemy

walter welch
walter welch

The dinosaurs were able to rule the earth for about 160 million years. I hope man can prove he is at least as smart as they were and set a new record.

Lets worry about the next million years. The rest after that should be easy.

Paul Green
Paul Green

The galaxy Andromeda will collide with the Milky Way before the earth burns up. We should look for a planet in Andromeda that will come close to our earth and plan to switch planets.  

Thierry Lombry
Thierry Lombry

Indeed, when the sun will be 10% warmer than today, well sooner that the red gian phase, animals surviving under the soil or in the water can no more support the heat and will disappear, preceeding the extincvion of plants and microbian life.

But as the Earth will continue to warm up, when the Sun will be 15% warmer than today, rivers and water of the oceans will evaporate, releasing a huge amount of water steam in the atmosphere.

At the end, in 2.8 bln years the life on earth will be impossible, the surface temperature exceeding 400°C.

Later, when the sun will enter into the giant red phase, its enveloppe will reach Venus, increasing the temperature on Earth to 1200°C.

The Sun will be 2000 times hotter than today and its size could reach 180 to 200 times its current size ! At that time, the Sun will shine 10,000 times stronger than today at magnitude -36 and will underlie a angle of 69° at the surface of the earth.

In some scenarii the Sun could reach the orbit of the Earth and even the one of Mars.

Omar Abdi
Omar Abdi

This prediction  is scary.But according to religious concept and prespecive 

the warld will end abrubtly  without warning and life ceases to exist one time for all species in a fruction of a second.When this incident happens life goes as usual as it is today or as normal no matter how it evolves as it continues to that day that nobody knows except God himself..

Oliver Wollsén
Oliver Wollsén

I for one don´t even think man will exist in a billion years. In less than, oh, 10 000 years, I believe drastic changes will have been made.

Biju Vamanan
Biju Vamanan

sure that we would have moved to a new home by that time

mike stanway
mike stanway

will we have moved to a new home long before the sun does its worst ? 

Biju Vamanan
Biju Vamanan

hope that by that time technology becomes so advanced that we could find a good solution

Dr. T. K. Stone
Dr. T. K. Stone

You cannot create nor destroy energy in this physical universe. Energy and its mass transforms into something new constantly. That is the physical world of change, what about the metaphysical world, the world of our minds. Yes the body needs to go somewhere to survive in this physical universe, seeking somewhere outside to move in a direction. What about the mind? The sages say the mind can also seek somewhere to go and that is somewhere inside us. Sages say the mind can find a place inside this physical experience that transcends this mind and body universe. Wow! What a concept that someone's mind created? Carl Jung said, "The ones who look outside dream and the ones who look inside awaken." What does that mean?

Devon Moody
Devon Moody

I dont think Cher will survive this....cockroaches of course 

Tom Pugh
Tom Pugh

A gamma ray burst could snuf a whole lotta things out, a solar wind may blow our atmosphere away, a few super volcanoes may explode, a variety of projectiles from space could smash into us, an errant Black Hole may drift by, or the Republicans may win the presidency. 

ajeeth mr
ajeeth mr

omg  its scray to think of the blue planet bcm red planet,,thnk god we r in blue planet


Rajakrishnan Chellam
Rajakrishnan Chellam

AT THAT TIME EVOLUTION WILL HAPPEN IN SUCH A WAY THAT, THE LIVING BEING CAN WITHHOLD EVEN THE SUN'S HEAT

Adam Glueck
Adam Glueck

I don't think we really need to worry about it these days

Seth Petra
Seth Petra

Maybe Mars will warm up enough in the meantime and develop a decent atmosphere.

Diego Felipe Reyes
Diego Felipe Reyes

Might be a  "new study", but it's old news. I've known this thesis about the sun since the 80's and most probably would have been formulated decades before that.  

Brian Jaimes
Brian Jaimes

Hmm If the sun wishes to end us... then we must end the sun first.

Ramnik Kaur  Josan
Ramnik Kaur Josan

All stars go through that. And the universe is so big, they might have life elsewhere. Our psychiatry professor at Medical College Patiala mentioned that man's ego is so big although man's size is so small compared to the big universe, might be microscopic etc.

David Ray
David Ray

The Earth will never be "healthy" as long as man is here. If history repeats itself, man will be long gone in less than a million years.

James Webb
James Webb

World ends in 1.4 million when a star comes within a light year.

michael g.
michael g.

what would happen. if a big enough asteroid hit the sun.

Jim Krafchik
Jim Krafchik

Hummmm. Only 500 million years left!

I do believe that it is time to start enjoying today!

norman h.
norman h.

Not to worry, through greed and ignorance humans will kill all life on the earth a long time before the sun does.

Christopher Dack
Christopher Dack

@Paul Green What a strange comment . Earth will be destroyed in 2.3 .   Plan to switch planets ?? why when we could have switched planets well before that . When Andromeda collides planets are not going to pass by us

Mika Joannette
Mika Joannette

@Paul Green Andromeda is expected to collide with the Milky Way in 4.5 billion years, we all die in 2.3 billion years 

Larry Prim
Larry Prim

@mike stanway  Nope. Even the closest planet is many, many, light years away; and we don't even know if it is inhabitable; and even if we had a way to get there everyone on board would be DEAD before they arrived. 

Dorian Mattar
Dorian Mattar

@Tom Pugh Yes, the sun is the least of our eminent worries.  If humans can survive religion and politics for another 500 years, they will have become a type 2 civilization by then, and would have control of all planets within our Galaxy.  In 2,000 years humans will probably be a type 4 civilization and would have control of everything in the universe.  When they reach type 5, they will be able to jump from universe to universe and will be like gods.  and that's just 2,000 years.

Adam Wu
Adam Wu

@Rajakrishnan Chellam 

Even evolution is limited by the laws of chemistry. No amount of evolution can save photosynthesizing organisms from the complete loss of atmospheric CO2. No amount of evolution can save microbes from the complete loss of liquid water. No amount of evolution will enable organisms to survive temperatures above the point when DNA is broken down.

Adam Wu
Adam Wu

@Diego Felipe Reyes 

The new study defines the timeframe more accurately. The old hypotheses postulated a very wide range of dates for exactly when plants would die off, and when all life would be extinguished.

Steven+ Leech
Steven+ Leech

@Brian Jaimes Thats A BIG star to snuff out,considering the earth is the size of a pin head compared to the mass of the sun...

Steven+ Leech
Steven+ Leech

@Ramnik Kaur Josan Microscopic is right....like I said above the earth is the size of a pin head compared to the mass of the sun,now imagine what humans look like in comparison. the sun rules the solar system we are in, i cant imagine what would happen if Jupiter was to go astray falling out of its orbit, now thats the largest planet in our solar system, that planet can reek havoc, lets look at ego now..

Yvonne F.
Yvonne F.

@michael green I don't think that there is one that big. The sun gets hit all the time. Many just burn up.

Adam Wu
Adam Wu

@michael green 

Nothing. 

To be big enough to have any effect at all, it would have to be so big that it wouldn't be an asteroid. We're talking Jupiter size big here. Even earth-sized would have no noticeable effects.

Adam Wu
Adam Wu

@norman h. 

All life?

No. Nothing humans can do will even come close to inconveniencing the bacteria as a group.

Charles Becker
Charles Becker

@norman h. Kill off the Human Species... most likely, but life will prevail and prosper without Humans here.  

Michael Schmidt
Michael Schmidt

@Religions have stated for a long time that the earth (and universe) will end, as we know them.  Science is starting to prove that to be true.  What surprises me is that science and religion are perceived as opposites.  if people open their minds to both, they will see that they can complement each other.

Nathaniel Gillen
Nathaniel Gillen

@Larry Prim @mike stanwaynot necessarily hopefully in a few thousand years we will have the technology to travel at the speed of light and even then if we did not we cold put people in stasis pods until they arrive at  their destination. but we have 2.8 billion years to come up with a plan.  

Yvonne F.
Yvonne F.

@Adam Wu @David Ray human free

Trending News

Celebrating 125 Years

Latest News Video

See more videos »