http://www.commondreams.org/headlines03/0725-04.htm
Published on Friday,
July 25, 2003 by the Independent/UK
Future Tense: Is Mankind Doomed?
by Charles Arthur
Is mankind doomed? Against the background of the war against terror,
the march of technology and environmental calamity, this has become
the defining question of our age. As politicians warn of the threat
from weapons of mass destruction, Prince Charles frets about the
world
being turned into 'gray goo' by miniature robots. Meanwhile, food
campaigners warn by turns that we're going to starve if we don't
plant GM crops, and if we do, there's barely time to heed warnings
that Sars was just a dress rehearsal for a pandemic that will
make
Ebola look like the common cold. Charles Arthur weighs fact against
hysteria, science against supposition - and assesses our chances
of making it to the year 3000
THE PASSAGE
OF TIME
Copernicus upset the
Church by pointing out that the Earth did not
occupy an exalted place at the center of the universe; instead
we orbited the Sun, along with some other planets. The "Copernican
principle" says that wherever or whenever we are, it's nothing
special. When J Richard Gott III, an astrophysicist from Princeton,
visited the Berlin Wall in 1969, he used the Copernican principle
to estimate how much longer it would last. It was erected in August
1961. He assumed that he was there at no special time in the
wall's life - not its beginning or end, just some time during
the other, say, 95 per cent of its existence. That meant that
it would last between 2.66 (if he was there 97.5 per cent into
its life) and 24 more years (if it was just 2.5 per cent along).
Twenty years later, it fell.
The same maths with
Homo sapiens (which appeared 200,000 years ago)
means that we'll last between 5,100 and 7.8 million years - but
not more. "Other mammal species' longevity is about two million
years," Professor Gott comments. "If we remain on Earth,
then
we're subject to the same probabilities as other species.
That's why the space program is so important."
Worry rating:
0/10. Lots of time to go.
TINY ROBOTS
AND GREY GOO
Imagine this: you're
standing around minding your own business
when a wave of nano-robots, so small you'd need a microscope
even to see them, comes along and starts using the atoms
in the clothes you're wearing to construct new versions
of themselves. Metal from your buttons, starch polymer
(the cotton) for fuel. Then those new ones start using
you - iron from your blood, all sorts of minerals in your
bones - to make copies of themselves. Within a few minutes
there's just an unsightly puddle where you used to be and
a whole stack more nano-robots looking for the next object
- living or dead - to use. Within days the planet is covered
with them, leaving nothing alive.
This is the "'gray
goo" scenario. Yes, the technology
to build cell-sized machines is within reach, but not
that needed to design machines able to replicate themselves.
In a 2001 paper entitled, thrillingly, "Some Limits to
Global Ecophagy by Biovorous Nanoreplicators, with Public
Policy Recommendations" (translation: how politicians can
stop 'gray goo eating the planet), Robert Freitas Jr noted
two points: first, the replication might generate so much
heat that the evil nanobots would fry themselves; and second,
that such "badbots" could be stopped by building "goodbots"
that only feed on the bad ones. Also, physics dictates that
the smaller something is, the greater its drag moving through
water or air. A nanobot could move about 2.5mm per second
- about the speed of a racing snail.
Worry rating:
0/10. If they're ever built, we can outrun them.
CHEMICAL WEAPONS
Dangerous, deadly,
and all around. World stocks of chemical
weapons amount to 80,000 tonnes - half of it in Russia,
stored in seven sites. Yes, the stuff is remarkably deadly
if it's released near you. But the problem with chemical
weapons for terrorists and nation states alike is that
they're unpredictable; the wrong weather can turn an attack
into a damp squib. And, although 12 people were killed
when the Aum Shinrikyo cult released sarin gas on the
Tokyo underground in 1995, more would have been killed
by a bomb the size of the canisters.
This doesn't mean that
terrorists, and terrorist states,
don't want chemical weapons. But they're hard to store,
hard to transport, and remarkably hard to deploy. Saddam
Hussein may go down in history as the last war leader
to use them. Everyone else prefers conventional weapons:
an explosion is so much more final.
Worry rating:
0/10. Civilization is not remotely threatened
by these stocks.
GERMS WE CAN
MAKE
"Within a few
years, it may be possible for an inexperienced
graduate student with a few thousand dollars' worth of equipment
to download the gene structure of smallpox, insert sequences
known to increase infectiousness or lethality, and produce
enough material to threaten millions of people," wrote
Henry Kelly, the president of the Federation of American
Scientists, in The New York Times earlier this month.
Maybe - though plenty
of experienced graduate students
could already have a stab. But nature knows that infectious
diseases are very hard to get right. Only HIV/Aids has
100 per cent mortality, and takes a long time to achieve it.
By definition, lethal diseases kill their host. If they kill
too quickly, they aren't passed on; if too slowly, we can
detect them and isolate the infected. Any mutant smallpox
or other handmade germ would certainly be too deadly
or too mild. And even Sars killed fewer people worldwide
than die on Britain's roads in a week. As scares go,
this one is ideal - overblown and unrealistic.
Worry rating:
1/10. Bioengineered diseases would be grim,
but short lived.
BLACK HOLES
When scientists began
building particle accelerators,
they wondered if there was a possibility that smashing
atoms together at huge energies might do something odd
to what Star Trek's Mr Spock used to call "the time-space
continuum". Such as, create some sort of subatomic hole
that would suck in other matter.
They decided that this
wasn't really a risk, because
it happens already around the universe, which is still
there - literally, as far as we can see. But in 1999
the question was raised again with the building of the
Brookhaven accelerator in the United States. Sir Martin
Rees, who is the Astronomer Royal, has evaluated the
possibility and worries about it in his latest book,
Our Final Hour. As accelerators get more and more powerful,
they might one day create a "strangelet" of hypercompressed
quarks (the smallest possible units of matter), which
would bind all matter to it and then collapse everything
- the whole universe - into a void that would spread out
at light speed from the place that used to be Earth.
You may think that's
something to make Mr Spock prick up
his ears - but the only people in any position to know
(the physicists who do this work) laugh off the risk.
If we're doomed, they reckon it's not by this method.
(And if it does happen this way, we'll know nothing about it.)
Worry rating:
1/10. Impossible to understand or estimate,
and will happen too fast if it does.
GENETICALLY
MODIFIED CROPS
In 1798, the mathematician
Thomas Malthus noted that
agricultural output grew arithmetically (1, 2, 3, ...)
but populations grew geometrically (1, 2, 4, ...).
To him, this suggested that starvation and disaster
were not far off. Our numbers are still growing,
but the GM lobby now says that we need genetically
modified crops to keep pace... or face disaster.
In contrast, the anti-GM
lobby thinks that using
those crops could itself be the disaster. "The impact
on soil fertility of GM is only poorly understood,"
says Stephen Tindale, the director of Greenpeace UK.
"There's evidence that the pesticides used on GM crops
hangs around longer in the soil, because it's not organic.
That can reduce fertility. And that could rapidly lead
to us not being able to feed ourselves. Far from being
the way to feed the world, it could be the biggest threat."
Worry
rating: 3/10. More research would clear this up.
VOLCANIC ERUPTION
Supervolcanoes - there
are only a few in the world
- lie dormant for hundreds of thousands of years,
building up magma and then exploding with earth-shattering
force. The last was in Sumatra, 75,000 years ago.
It threw up enough volcanic dust to block out the
sunlight, and it changed the course of life here:
global temperatures fell by an average of 11C.
The dust made the rain acidic. Three-quarters
of the plants in the northern hemisphere died,
and humans were pushed close to extinction - just
a couple of thousand survived.
One example of a supervolcano
is Yellowstone, the national
park in the US. Scientists only realized it had a crater
when they looked at satellite photographs. And when is it
due to go off? Apparently, it should explode every 600,000
years... and it last exploded 640,000 years ago.
If, or when, it goes
off, tens of thousands will die almost
immediately, and the world's harvests will fail dramatically.
Humans could once again face being snuffed out. What can we do
about it? Unfortunately, nothing at present. Best buy a sweater
while you're out.
Worry rating:
6/10. Big and, like other volcanoes, unstoppable.
AN ASTEROID
STRIKE
The dinosaurs did not
have Bruce Willis to save them,
Armageddon-style, from impending doom 65 million years
ago when an asteroid struck the planet. Unfortunately,
neither do we. Despite the publicity about the hundreds
of big and small rocks floating about our solar system,
governments aren't funding a program to spot them early
enough, before they come dangerously close. "If we're due
to be hit within a day, week, month or year, we aren't
going to spot it," says Professor Duncan Steel, reader
in astrophysics at Salford University, who has done much
to alert politicians to the dangers through The Spaceguard
Foundation. "But if one's due in 50 years, I think we could
spot it. I do get called a doom-monger, but while it's true
that an asteroid could hit Earth and push us back into the
Dark Ages - it's unlikely, but possible - I'm optimistic
that we have the scientific and technical capability to
detect and divert it."
Even so, he thinks
that it might take a cosmic calling-card
to wake everyone up: something like the meteorite that came
down over Tunguska, Siberia, in 1908. That was about 50 meters
across and exploded in the atmosphere with the force of a
10- to 20-megaton bomb. Had it entered the atmosphere a
few minutes earlier, it would have devastated London.
Such events happen about once a century, on average.
So statistically speaking...
Worry
rating: 8/10. We have house insurance but not
planet insurance. Is that sensible?
CLIMATE CHANGE
"The biggest threat
we face is climate change," says
Stephen Tindale of Greenpeace UK. "Especially, positive
feedback loops forming within the climatic system."
He worries that we might suddenly cross a threshold
which would cause a flip in our climatic systems -
melting the permafrost in the Arctic, thus releasing
more methane into the atmosphere and speeding up climate
change even more. "That's the most worrying prospect,
and the one where we can say there's a possibility,"
Tindale says. That wouldn't wipe out the planet, but
it would leave a small group of survivors scrabbling
for subsistence. "It would be the end of Civilization,
and of political and economic structures," he says.
"It's not entirely far-fetched."
Of all the doom scenarios,
this is the one that's
hardest to discount, because scientists know that
our climate uses many complex feedback loops that
they don't fully understand. Breaking one of them
down might be just the bad news we don't want to hear.
But Tindale adds: "We are optimistic, though, that
it's possible to address these doom scenarios through
the use of new technology. Look at the ozone layer
- 15 years ago that would have been high on the doom
list, with the suggestion that we'd all be about
to die of skin cancer. But governments acted and
now it's healing. Now we need the international
community to get together again."
Worry
rating: 9/10. It's real, happening now,
and we can do something about it.
So what are our prospects?
It might seem surprising
that politicians and media alike spend their time rowing
about who last saw the weapons of mass destruction and
how many lanes the motorways should have. The problem
is that these threats tend to fall into two categories:
those that make a good sound bite ("'gray goo" is a
rising star) and those that are vital but involve making
sacrifices (climate change). Being human, we're better
at worrying about short-term things than taking care of
long-term issues, even when the latter are more important.
It may be that the
only real way for us to avoid doom is,
as a species, to grow up a little. It may take a "species
incident" - an asteroid obliterating a major city, or a
volcano devastating a continent - before we realize that
J Richard Gott's comments really do apply to all of us.
Asked where he would go if he had a time machine for an
hour, he replied: "210,000 years into the future, to see
if we're still here. Because I think the message from
the future is - don't waste your time, humanity.
You have just a little of it."
© 2003 Independent
Digital (UK) Ltd
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