'The End Of The World' Has Already Begun, UW Scientists Say
Ron Baalke
University of Washington
Seattle, Washington
FROM: Vince Stricherz, 206-543-2580, vin...@u.washington.edu
FOR IMMEDIATE RELEASE: Jan. 13, 2003
'The end of the world' has already begun, UW scientists say
In its 4.5 billion years, Earth has evolved from its hot,
violent birth to the celebrated watery blue planet that
stands out in pictures from space. But in a new book, two
noted University of Washington astrobiologists say the
planet already has begun the long process of devolving
into a burned-out cinder, eventually to be swallowed by
the sun.
By their reckoning, Earth's "day in the sun" has reached
4:30 a.m., corresponding to its 4.5 billion-year age. By
5 a.m., the 1 billion-year reign of animals and plants
will come to an end. At 8 a.m. the oceans will vaporize.
At noon -- after 12 billion years -- the ever-expanding
sun, transformed into a red giant, will engulf the planet,
melting away any evidence it ever existed and sending
molecules and atoms that once were Earth floating off
into space.
"The disappearance of our planet is still 7.5 billion
years away, but people really should consider the fate
of our world and have a realistic understanding of where
we are going," said UW astrophysicist Donald Brownlee.
"We live in a fabulous place at a fabulous time. It's a
healthy thing for people to realize what a treasure this
is in space and time, and fully appreciate and protect
their environment as much as possible."
In "The Life and Death of Planet Earth," Brownlee and
UW paleontologist Peter Ward use current scientific
understanding of planets and stars, as well as the
parameters of life, to provide a glimpse of the second
half of life on Earth and what comes after.
The book, a sort of biography of our planet, is being
published today by Times Books, a division of Henry Holt
and Co. It is a sequel to Ward and Brownlee's best-selling
and much-discussed book "Rare Earth," in which they put
forth the hypothesis that simple life is relatively common
in the universe but complex, Earth-like life is exceedingly
rare.
"The Life and Death of Planet Earth" explains how the
myriad life on Earth today was preceded by a long period
of microbial dominance, and the authors contend that
complex life eventually will disappear and be succeeded
again by a period of only microbial life. They say that
higher life will be removed much as it came into being,
ecosystem by ecosystem. Aspects of the planet's past,
such as numbingly cold ice ages, will be relived in the
period of devolution.
"If we do begin to slide into the next glacial cycle,
there probably are grand, planetary-scale engineering
projects that might stop or lessen the effects," Ward
said.
"The big unknowns are whether we can afford to do such
projects and would we really know what to do. If the
planet was cooling, we could, in principle, begin
painting the surface black to collect more heat. Could
we afford it? And what would be the many possible
ramifications of a planet suddenly covered in black
paint? Any planetary remediation project would always
run the risk of making things worse."
Eventually, though, scorching heat will drive land
creatures to the sea for respite. Those that can adapt
will survive for a time, but eventually the oceans will
warm too much for the complex life forms to continue.
"The last life may look much like the first life -- a
single-celled bacterium, survivor and descendant of all
that came before," the authors write. Finally, even the
surviving microbes "will be seared out of existence."
The prospects of humans surviving by moving to some other
habitable planet or moon aren't good, Brownlee and Ward
contend, because even if such a place were found, getting
there would be a huge obstacle. Various probes sent into
space could survive Earth's demise, and just a few grams
of material could arguably carry a DNA sample from every
human, they say, but it's not likely the human species
itself will survive. Long before the planet's final end,
life will become quite challenging, and finally
impossible, for humans.
As the sun gets hotter and grows in size, it will envelop
Mercury and Venus. It is possible it will stop just short
of Earth, the authors say, but the conditions still would
make this a most-inhospitable planet. More likely, though,
the sun will consume Earth as well, severing all the
chemical bonds between molecules and sending its
individual atoms out into space, perhaps eventually to
form new planets. That would leave Mars as the nearest
planet to the sun, and on Mars the fading sun's glow
would be like that of Earth's moon.
That end is still some 7.5 billion years distant, but by
then Earth will have faced a variety of "ends" along the
way, the authors say. The last dinosaur perished long ago.
Still to come are the last elephant, the last tree, the
last flower, the last glacier, the last snowflake, the
last ocean, the last life.
"The Life and Death of Planet Earth" is like its predecessor,
"Rare Earth," in that the authors collected and distilled
some of the latest scientific ideas about the Earth's place
in the universe, Brownlee said. He hopes the new book, like
"Rare Earth," will spark widespread discussion, and give
people a fundamental and realistic view of the past and
future of their planet.
"It's a healthy thing to think of the place of Earth among
the other planets, and its place in the sun. The sun gave
life and ultimately it will bring death."
###
For more information, contact Brownlee at (206) 543-8575
or brow...@bluemoon.astro.washington.edu or Ward at
(206) 543-2962 or ar...@u.washington.edu
IMAGE CAPTION:
[http://www.washington.edu/newsroom/news/images/earthclock.jpg (222KB)]
An illustration from "The Life and Death of Planet Earth"
shows the authors' view of the Earth's clock of life.
(Image credit: Donald Brownlee/Peter Ward)
Joe Strout
baa...@zagami.jpl.nasa.gov (Ron Baalke) wrote:
> "The big unknowns are whether we can afford to do such
> projects and would we really know what to do. If the
> planet was cooling, we could, in principle, begin
> painting the surface black to collect more heat. Could
> we afford it? And what would be the many possible
> ramifications of a planet suddenly covered in black
> paint?
This is rather silly. We're talking about something that will most
likely begin thousands of years from now. If we're still here and still
care enough about Earth to save it in its natural state, we will surely
have more advanced technologies at our disposal than painting it black.
(Examples: giant mirrors that focus more sunlight onto the Earth, or
even artificial "stars" -- giant light/heat generators powered by fusion
-- in orbit.)
Of course it's equally likely that by the time this has happened, the
world will be one giant enclosed city, in which case things like cooling
of the planet would be a minor inconvenience, noticed only by those who
bother to go up to where the windows are now and then.
> Eventually, though, scorching heat will drive land
> creatures to the sea for respite. Those that can adapt
> will survive for a time, but eventually the oceans will
> warm too much for the complex life forms to continue.
Rubbish again. This would be a sensible prediction if you ignore
technology, but now we're talking millions or billions of years from
now. By that time, if we're still around and interested in the Earth,
we'll certainly be able to fix this minor problem in a number of ways.
Even my primitive 21st-century brain can think of some: e.g., giant
shields in orbit blocking out just the right amount of sunlight.
> The prospects of humans surviving by moving to some other
> habitable planet or moon aren't good, Brownlee and Ward
> contend, because even if such a place were found, getting
> there would be a huge obstacle.
More ridiculous nonsense. Even the Moon will be "habitable" in the next
century or two. That's what technology does: it makes previously
uninhabitable niches inhabitable. By billions of years from now, when
the Sun becomes a red giant, we will have spread throughout the galaxy.
If we even remember our planet of origin by that time, and somebody
cares enough about it to use a small fraction of their wealth to save
it, doing so will surely be trivial. But even if not, finding places
for human descendants to live will NOT be an issue. We will have
abandoned planetary surfaces billions of years earlier.
Indeed, by that point we should be worrying not about the descendants of
humans, but about the several other technological civilizations which I
hope would arise on Earth by that time after we had moved on.
> Various probes sent into
> space could survive Earth's demise, and just a few grams
> of material could arguably carry a DNA sample from every
> human, they say, but it's not likely the human species
> itself will survive. Long before the planet's final end,
> life will become quite challenging, and finally
> impossible, for humans.
What silliness. How can a scientest make such absurd claims? They're
taking 21st-century humans and mentally putting them into a situation
that will happen billions of years from now, without positing any change
at all in humans or their technology in all that time. That is absurd.
Either we will have died out for other reasons, or our technological
progress will have continued, and we'll have spread throughout the
galaxy billions of years before this issue comes up.
> He hopes the new book, like
> "Rare Earth," will spark widespread discussion, and give
> people a fundamental and realistic view of the past and
> future of their planet.
Discussion yes, but realistic view of the future, no. Earth is
inhabited by a technological race. You can't speculate realistically
about its future without taking into account future technology.
> "It's a healthy thing to think of the place of Earth among
> the other planets, and its place in the sun. The sun gave
> life and ultimately it will bring death."
Bokum. The sun gave life, life gave rise to intelligence, and
intelligence will decide when and whether Earth meets its final fate.
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