Could the world end in 2012? Put aside the goofy prophecies of
Mayan calendar doomsayers and join us on a journey into the cold, hard
science of civilisation ending catastrophe. Predicting the end of the
world is both a sure bet and a fool's errand. Eventually, the total
destruction of civilisation, the human race, and, indeed, the world is a
near certainty. The tricky part about predicting the apocalypse is the
timing. But that hasn't stopped people from forecasting impending doom
throughout human history. Holy men, ancient astronomers, and even modern
computer scientists have all occasionally read the leaves in their
occupational cups of tea and concluded that the end is nigh. And,
without exception, they have all been wrong.
But maybe this year
is going to be different. On Dec.21, 2012, the Mayan calendar will reach
the end of a 394-year cycle called a Baktun, which has sent end-time
aficionados into a frenzy. Archaeologists laugh off that doomsday
scenario, explaining that the Mayan calendar is no more momentous than
our own calendar ticking over from 1999 to 2000. So that's a relief.
Still, just because the Mayans didn't predict the end of the world this
particular year doesn't mean our safety is assured. There are plenty of
other risks to life on earth that scientists do take seriously. These
might range from disasters that threaten millions or billions of people
to an all-out "extinction-level event" that wipes out the majority of
life on the planet. Below we will take a look at the top 10 ways the
world will end in 2012.
Asteroid Impact
Space
objects strike the earth all the time, but extinction-level impacts
occur only once every 100 million years. After the spectacular collision
of the Showmaker-levy 9 comet with Jupiter (and a host of
asteroid-disaster flicks) in the 1990s, NASA set out to map all large
near-earth objects. But it appears that there are far fewer potential
catastrophes in earths neighbourhood than once thought. "A
civilisation-killing asteroid would have to be a mile across," says
Spahr of the Minor Planet Center. (The space rock that ended the
dinosaur era is estimated to have been six times that size.) "There just
aren't any asteroids that size out there," he says. There is, however, a
large population of as-yet-undiscovered objects several hundred yards
across. One that we do know about, a 300-yard-wide asteroid called 99942
Apophis, will pass within the orbits of earth satellites in 2029 and
could one day strike the planet. "Worst-case scenario?" Spahr says."You
hit Los Angeles, kill millions of people, and shut down the entire West
Coast."
Pandemic
For a disease to be
globally destructive, it must undergo a flare-up of contagiousness and
lethality like the 1918 influenza pandemic, which in the course of two
and half years killed 50 to 80 million people. If the next influenza
pandemic is as bad as 1918s, the equivalent toll would be 210
million."Knocking off that many people at once would disrupt
civilisation,' the CDC's Khan says. He adds, however, that in the past
century medical science has developed powerful weapons against
disease."we're an intelligent species,"he says"We can fight back." But
what if that intelligence were turned against us? Thanks to advances in
biotechnology, it will become increasingly possible to custom-tailor a
pathogens lethality. "we're on the cusp of what could be a frightening
time," says Charles P. Blair, director of the Terrorism Analysis Project
at the Federation of American Scientists."I think in the very near
future you're talking about a potential extinction event.
Machines Take Over
Moore's
law-the observation that computer chips get twice as powerful every two
years-implies that, eventually, artificial brains will eclipse the
human brain. The big question is, what will the artificial
super-intelligence of the future choose to do with it's gifts? "The risk
is not so much a Terminator scenario, where you get a super computer
that dislikes humans,"says Anders Sandberg, a researcher and futurist at
the Oxford Martin Schools Future of Humanity Institute in England."A
malign neglect would be a bigger problem. You get something that's very
intelligent but has motivations that are completely non-human. [The
computer] might not really care about anything that we care about, but
since its smarter, it's going to get what it wants."
Gamma-Ray Bursts
When
large stars die, they go out in spectacular fashion. Having used up
their nuclear fuel, their cores collapse inward into a black hole, which
then devours the star inside out. Out of this paroxysm of destruction,
powerful beams of energy burst from both poles, shooting gamma rays and
charged particles that for a second outshine the rest of the stars in
the universe combined. That's great for astronomers, who can observe the
gamma-ray bursts, or GRBs, from across the universe, but not so good
for any planet that happens to be located in the path of the beams. In a
one-two punch, a bath of charged particles would quickly kill
everything on one side of the planet while intense gamma rays would
ionize the atmosphere and cause years of acid rain. "As a rule of thumb,
the danger zone extends to anything within 3000 light-years," says Penn
State astronomer Derek Fox, who specializes in gamma-ray bursts. But
for us, he says,"it's not a likely threat." The average galaxy
experiences a GRB only every 10 million years or so, and the danger zone
is a small percentage of that galaxy.
Snowball Earth
Right
now people worry about global warming, but fallout from a nuclear war
or a super volcano could put enough sunlight-blocking dust in the air to
cause the opposite problem: a deep plunge in surface temperatures. If
the earth stayed cool long enough, a worse catastrophe could ensue. Back
in the 60s, climate modelers realized that if the earth were covered in
enough ice, most of the incoming solar radiation would be reflected
back into space and the planet would settle into a stable state at about
minus 50 degrees F. Then, in 1992, Cal-Tech Geobiologist Joseph
Kirschvink proposed that the earth had once spent long stretches of time
almost entirely frozen over, leaving evidence of glacial deposits in
the tropics. Life clung on in a few sanctuaries heated by volcanic
springs. Could it happen again?"Its not something you would need to
worry about in 2012, or the next hundred years,"Kirschvink says."Even if
the climate became very cold, it would take a long time for glaciers to
build up."
Solar Storm
Late last year a
major solar storm launched a wave of charged particles through the solar
system at 4 million mph, setting the stage for a display of northern
lights that could be seen as far as Arkansas. But while delightful to
the eye, such a storm could someday herald a disaster. The earths
magnetic field prevents the suns deadly particles from striking the
surface. The motion of those particles, however, can induce strong
currents on the ground. During the worst solar storm ever recorded, in
1859, the currents were so intense that telegraph lines burst into
flames."If we had a storm like that today, it would be possibly quite
catastrophic,"says Jeffrey Love, a geomagnetic researcher with the U.S
Geological Survey. "Months without electricity could cause losses of
trillions of dollars and basically wreck the economy."
Super Volcano
Two
million years ago, a massive volcanic eruption near what is today
Yellowstone National Park shot 600 cubic miles of dust and ash into the
atmosphere, 2400 times more than Mount St. Helen's did in 1980. If such
an eruption happened today, "it would greatly interrupt business as
usual around the planet." Since that ancient blast, massive eruptions
have been taking place every 600,000 years or so, and the last one was
640,000 years ago. On the bright side, the intervals between the
Yellowstone volcano eruptions are extremely erratic. Statistically
speaking, it's very unlikely to blow in 2012, or even within the next
millenium.
Geomagnetic Reversal
Right now,
the magnetic north pole is up near the rotational north pole, but this
hasn't always been the case. Throughout the earths history, the north
and south magnetic poles have swapped places, a phenomenon known as
geomagnetic reversal. It happens irregularly, every 100,000 to 1 million
years, and the last time they flipped was 780,000 years ago. So maybe
we're due. Geophysicist J. Marvin Herndon has suggested that the
reversal could cause the geomagnetic field to temporarily collapse,
disrupting everything from power grids to gas pipelines to communication
satellites. But there's also no need for immediate panic. While a flip
would occur quickly on a geological time scale, it is far longer in
human terms, between 1000 and 10,000 years. "Whether it's going to do us
harm is an academic question," says Jeffrey Love of the U.S. Geological
Survey, "because it's not going to happen tomorrow, and it's not going
to happen in our lifetime.
Nuclear War
On
Sept.26, 1983, a satellite-monitoring unit at a secret facility near
Moscow received a warning: Five nuclear missiles had launched from a
base in the U.S. Luckily, the unit's officer, Stanislav Yevgrafovich
Petrov, was sceptical about the reliability of newly installed
equipment, and he chose to wait rather than immediately pass along an
alarm that might trigger a nuclear war. His judgement may have saved
millions of lives. Nuclear tensions have subsided since the end of the
Cold War. But the threat remains. More countries than ever have the
bomb, and terrorist groups and rogue states remain a worry. A study
published in 2008 by the journal Physics Today suggests that a regional
war involving as few as 100 bombs could cause a nuclear winter,
resulting in the lowest temperatures in 1000 years, while an exchange
involving thousands of weapons would, the study concluded, "likely
eliminate the majority of the human population". "Nuclear war is the
near-term risk that people tend to forget about," says Sandberg of
Oxford Martin. "If you think historically, we've probably been very
lucky."
Artificial Black Hole
In 1945, a
physicist working on the first atomic bomb raised a disturbing
possibility: What if the energy released by the fissioning nuclei
ignited the atmosphere and wiped out life on earth? Obviously, that
didn't happen, and mankind survived its entry into the nuclear age. But
the notion that physicists could unwittingly trigger a world-ending
catastrophe has not gone away. In 1999, as the Brookhaven National
Laboratory prepared to fire up its Relativistic Heavy Ion Collider
(RHIC), a Hawaiian man named Walter Wagner filed a lawsuit to have the
facility shutdown. He claimed that the collision of high-energy
subatomic particles could spawn tiny black holes that could subsequently
grow until they swallowed the earth. In more than a decade of operation
the RHIC has not produced a black hole, but Wagner is currently warning
of the same danger for Europe's Large Hadron Collider, which is
generating yet higher energies. Mainstream physicists dismiss the
threat. "This danger simply does not exist," says Brookhaven Lab
physicist Dmitri Kharzeev. "These energies are high in human terms, but
the cosmic rays that naturally occur in space are much more energetic.
If high-energy particle collision could produce black holes, one would
have swallowed us a long time ago."
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