What
the chances are that the human species will be destroyed in a mass extinction
like the Dinosaurs were? Not much and, surprisingly, we have even the meanings
to avoid it.
The
Dinosaurs became suddenly extinct at the end of the Cretaceous,
the last period of the Mesozoic Era,
about 65 million years ago. Their extinction was an enigma for a long time. It
still is, but some years ago scientist formulated a new theory that might
explain it.
Looking
at the sediments deposited between the end of Mesozoic and the beginning of the
Tertiary Era,
it can be seen that they are very similar, besides the great difference in
fossils content. Those sediments were deposited on the bottom of a shallow sea
continuously during the two geological periods. The boundary
between the sediment layers, called K-T, is very thin; it was deposited perhaps
during a few thousand years, almost nothing in geological terms. About twenty
years ago L. Alvarez found that the concentration of the rare element Iridium,
very stable in the Cretaceous layer, peaks abruptly at the boundary layer, to
return to its normal values in the Tertiary layer. Later other scientist
confirmed the same K-T peak worldwide for Iridium and other rare elements as
well. What is the meaning of all this? The
theory states that the Iridium surplus was an outsider, brought by a comet
or a meteorite rich in it, which hit Earth. The celestial body ought not to be
very big, a few tenth kilometer in diameter is enough, to raise so much powder
and other solid particles in the air, to obscure the sky all over the entire
Earth for many months, long enough to stop Photosynthesis and disrupt the
global food chain: “No Sun-no food, and the Dino gone for good”.
The
Cretaceous mass extinction was not the only one; it not even was the greatest
of them all. Fossil records show that many times
in the course of Earth history life has almost been destroyed. The meteorite
link triggered new research and soon scientists found a strong time correlation
between the frequency of big impact craters creation (the small one are eroded
and disappear) and the mass extinctions. Apparently once every 25-30 million
years a mountain-sized celestial body hits Earth, partially destroying the life
on it. Astronomy helps us to understand the cause: the Sun is not a single
star, but has a companion, nicknamed Nemesis
(Goddess of Punishment), which has an orbital period of about 26 million years.
When Nemesis approaches the perihelion it pushes towards the inner Solar System
a myriad of cometary bodies that normally wander at the edge of the system. The
Earth gravitational field captures one or more of them and they fall on us.
Astronomers did not find Nemesis yet, but they say it can be a very dim star or
a dark body like a brown dwarf. If and when Nemesis is found the
comet-extinction theory will be almost demonstrated. How much have we to be
concerned? Not at all! Since the dinosaur extinction Nemesis completed almost
exactly two and a half orbit. It is now the furthest it can be. It will take
about 13 million years before it returns to punish the human haughtiness. We
can forget of Nemesis. Still… perhaps the danger is nearer to us, in the inner
Solar System. A myriad of celestial bodies called asteroids orbits the sun,
most of them with a regular orbit in the space between Mars an Jupiter, the so
called Asteroid Belt,
but some of them approaches more the sun, crossing the Earth’s orbit. There is
a very small, but still real possibility, that one of them will hit our planet.
It cannot be ruled out and perhaps it happened in the past. Since the discovery
of the Earth-crossing
asteroids astronomers are constantly looking for them and calculating their
orbits. We are perhaps not aware of this, but the ‘Solar System Baywatch’ is
alert every night. If scientists come to the conclusion that some asteroid is
going to hit Mother Earth, they will promptly inform
our government officials. Meanwhile it seems just a science fiction story,
but in case of necessity we will have hopefully quite a few years, enough time
to send up several missiles with atomic warheads not to destroy the asteroid,
but rather to shift its orbit enough to miss the hit. There are good success
chances, if we are alerted in time.
In
the course of human history there were other mini-extinctions, provoked by
natural causes. Some mini-extinctions belong to legend, like Atlantis
and The Flood.
Others happened in historical times. A major Bubonic plague struck XIV century
Europe: The Black Death.
The disease, originated in China around 1330 A.D., broke out in Europe,
according to the tradition, as a result of biological warfare (which is not as
new as someone might think!). Contaminated
corpses where thrown over the wall of a besieged town near the coast of the
Black Sea. The plague, carried by rats on vessels, reached the Italian harbors
in 1347 and spread all over Europe. It ravaged for five years. By 1351 about
25,000,000 people, one third of the European population was dead. Historians
put the end of the Middle
Ages at 1492, the year Columbus
discovered America, but this is a late date. The process that led to the Modern
Era began with the Black Death one and a half century earlier. European economy
and society changed drastically following the Black Death. Because so many
people had died, there was a huge labor shortage. This contributed to the end
of the feudal system, since serfs could often leave their manors and make a
better living in cities. In addition to better work opportunities, survivors of
the plague had a surplus of material goods. Through these factors, Europe
experienced an overall rise in its standard of living. The best example of the
changed social and economical attitudes can be seen in Italian Tuscany, the
heart of Renaissance. The ruler family of Florence, the Medici, led a wise
foreign politics between the powerful nation around, based mostly on wealth.
Tuscany of XV and XVI century was the safe of Europe, a place where money could
be kept. Florence filled a role similar to modern Swiss. Even the powerful
Christian Church had to close her eyes when Florence, in bad need of a new
harbor (The Arno’s outlet had filled Pisa’s harbor with sand) decided to allow
freedom of cult to the Jews expelled from Spain if they go to live in the new
harbor town of Leghorn.
The Jews had still good relations with their relatives in the Arab world, on
the other side of the Mediterranean Sea, and someone had to keep the business
with the enemy going on. Faith paid a price to Economy. The expanding business
pushed the European rulers to seek for new raw materials and markets and to
send ships out to sea to reach for them. From 1487 to 1522, a matter of 35
years, Bartolomeu Dias doubled the Cape of Good Hope, Vasco De Gama reached
India, Columbus discovered America and the Magellan’s crew (he was killed
during the journey) circumnavigated the globe. The entire process from a
dreadful disease that killed an economy around the village to explorations that
started one around the globe, took about two centuries.
An
old adage says that history repeats herself. Is this true? Try for a moment to
strip out all the overcrowding particulars and stick to the kernel of the
historical process. Try to do some analogies and parallels. Although you might
come to conclusions that will prove wrong, you will perhaps be able also to
foresee things that you would prefer never to happen.
At
the beginning of the eighties a
strange disease spread among homosexuals, drug addicts and hemophiliacs,
killing them by the numbers. It took a few years to realize that a new viral
agent was attacking the cells at the very heart of their immune system. The
disease was named Acquired ImmunoDeficiency Syndrome – AIDS; the viral agent Human
Immunodeficiency Virus – HIV.
During
the following twenty years the AIDS Pandemic has spread all over the world. As
for end-of-2001 estimates, about 40 million people are affected by AIDS/HIV,
70% of them in Sub-Saharan Africa. Big figures do not say much to ordinary
people, they say even less to people, who heard of the disease only from the
media, so I will present the data in a slight different manner: one in 150
adult people in the world is affected by the HIV virus. In Sub-Saharan Africa
the figure is one in 11 (eleven!). Pick up a dozen of adult Africans at random:
one of them has AIDS.
Since AIDS is a fatal
disease, huge efforts have been made to curb it. The best minds worldwide are
actively conducting a research work worth thousands of hours and billions of
dollars. Despite of the big efforts, no remedy able to defeat the disease has
been found yet, but we are confident that sooner or later the scientists will
found the panacea. Ten years or so from now AIDS will surely be no more than an
old nightmare. After all we are no more in the Middle Ages. We have
Antibiotics. We have vaccines. We even experienced the global effort of
defeating the Smallpox, transforming this once worldwide disease in a controlled
endemic one. We are perhaps too confident. What if… we just missed the train?
Let’s
assume for a moment that no remedy is found in the near future, where for
remedy I mean something like a vaccine able to immunize healthy people from
contracting the disease or a medicine able to destroy the virus in vivo.
The AIDS Pandemic will relentlessly spread almost exponentially as more and
more people are infected. The ‘almost’ is because meanwhile people infected by
the HIV virus are constantly dying. Is it entirely unreasonable to think of a
ten times greater figure at the end of another decade? Might the HIV virus
infect 400 million people all over the world by 2011?
If
a remedy is found in the near future, how long will it take to carry out a
global vaccination, till the fate of AIDS is similar to that of the Smallpox?
Who is going to produce all that vaccine? Who is going to pay for it?
How can we asses whether the vaccine is effective in the long run or is
becoming ineffective, because a resistant strain of the virus in now on the
scene?
The
reader might well say that I am asking a lot of annoying questions, without
giving an answer. I do not mean to. These questions are only the tip of the
iceberg. Who is saying that the estimates above are right? First, the figures
might be already obsolete when this book is published. Second, they might be
underestimates, because what is called in medical laboratory terminology a
false-negative test result. AIDS is around only about 20 years. We do not know
yet whether the virus is capable to hide itself in the human body and pop up,
say, after an entire generation. May be the dormant virus is in there, but no
test will detect it. What about a late-effect syndrome of those who managed to
overcome the infection? We had some experience with the Post-Polio Syndrome
already.
Last,
but not least, let’s take a look at this appalling disease from a different
point of view. AIDS is not yet the major cause of death. Heart conditions,
cancer and Malaria are still killing more people around the globe. But AIDS,
being transmitted mainly by sexual relations, is a disease of the young,
sexually active people. Many infants already ill are born every day from
infected pregnant woman. AIDS, if non-stopped, is undermining the very
existence of the next generations, especially in Sub-Saharan Africa and other
developing regions.
Some
cynic might be tempted to affirm that AIDS will be the ultimate remedy to the
World Overpopulation Problem, especially because it decimates under-developed
people.
I
have bad news also for that cynic. As I will try to explain in another part of
this book, people from developing countries already started to migrate into the
developed countries. Nothing is going to stop them. They will bring mainly good
labor force and new blood to the sophisticate and decadent western nations,
but, alas! Some of them will carry with them the HIV virus too.
Let’s
compare the Black Death with the AIDS Pandemic. At the beginning in both cases
people sought for a human culprit. In the Middle Ages it was witches and ethnic
minorities. Now we use the euphemistic term “Population at risk”. Religious
people sought some God’s Punishment
(Because
the ‘Free Love’ of the sixties?). But when it comes to the bottom line the only
thing we can say is that people are dying from the disease. No more.
Are
we at the dawn of a new mini-extinction? Is the world population going to be
decimated by AIDS? Even so, the hope for the human species is not entirely lost
because, by analogy, some New Renaissance will be the scenario for the
survivors, at the end of the XXI century.
All
this, of course, if and only if no remedy is found in the near future.
I
will not be surprised if at this point the reader is tempted to close these
pages (and the eyes too) and say that she or he is not willing to hear anymore
from this prophet of doom.
Please
don’t: I have some additional less frightening bad news in my bucket, but also
a few good news and a happy end. Be patient.
Weather
forecasting was, until recent years, the wizardry of meteorologists and a font
of jokes and popular believes: “Grandfather said his old wound aches… so, in
spite of what they are saying on television, it is better to cancel our picnic,
‘cause tomorrow is raining!”…
Satellites and supercomputer technology
changed all this. Now is possible to have a very reliable forecast for the next
four-five days (and this is wonderful for long-weekend planning!). In fact
supercomputers were developed mainly to crunch data involved with air
turbulence analysis. But meteorologists can do even more: they provide us with
seasonal and annual forecasting. The state of art is still in cradle, yet
already good enough. The long-range forecasting is based mainly on statistical
analysis of the past seasons: meteorologists are collecting data on
temperature, air pressure and rainfall quantities for more than a century. Now
supercomputers can crunch these huge amounts of data and give us outputs about
similar patterns. Although we cannot prevent floods and droughts, if we know
with fair approximation that they are coming, at less we can take some steps to
reduce the damage. What was, not so long ago, caprice of nature (or God Will,
if you are a believer) will be a sophisticate and useful science field in the
near future.
In
recent years successful efforts have been made to understand better the weather
patterns on a global scale. This is the reason why you certainly heard of “El Niño”. Along
the western coast of South America flows a cold oceanic stream, bringing cool
and fresh waters from Antarctica to the equatorial coasts of Peru. There the
stream turns left (anticlockwise), passes the Galapagos and warms up in its
journey westward. Cool oxygenated water, together with sunny tropical days, is
good for plankton. Fishes like plankton very much and … fishermen, of course,
like fishes. The coasts of Peru are one of the richest fishery fields in the
world. But once in about four years – take or leave three – something goes
wrong. At about Christmas time the waters warm up and stay warm for a while.
For the poor Peruanos fishermen this is a very bad season. The word niño in
Spanish means child; written in capital means the Christ Child, born on
Christmas, so the Peruanos fishermen nicknamed the bad season “El Niño”.
Although the phenomenon is well known and recorded for at least a hundred
years, only recently, thanks to the new technologies, scientists began to
understand that El Niño is some more than a local fishing problem. It is part
of a global atmospheric and oceanic periodic interaction. At the same time El
Niño drives out the fishes from Peru, there are floods in California, mild
winters in New England and more bush fires in Australia. Generally speaking,
the once-in-a-few-years phenomenon is part of periodic fluctuations that
encompass the entire globe. A global dance. The analysis showed also that some
years the Peruan waters cool even more then usual. This phenomenon was nicknamed
“La Niña” (the sister of “El Niño”). Again, the scientists noted that elsewhere
on the globe rainfalls and drought are time-linked to La Niña. Sometimes both
phenomena are called together “Los Niños”. They are dancing a “Paso doble”
(double-step) dance: with the atmosphere and between themselves.
Lets’
do a little switch to a real dancing ground. There we can see very good dancers
swinging their Tangos and Rock-and-Rolls. We envy them a little. Why cannot we
look the same? Why we seem so ridiculous trying to make a few steps according
to the music, possibly not on the companion’s foot? But we want to enjoy
the party anyway, so we try and discover soon that nobody is criticizing us.
Most people there are not good dancers; they came to have a good time exactly
like us. And while we are jumping in the middle of the dancing floor, we look
to some outsider as very good swingers as well.
We
merged with the environment.
There
are two ways to cope with Nature. One is to try to command it. The other is to
flow with it. In this context the technological advanced Occidental world can
learn a lot from The Far East’s philosophy. The human species has become the
Master of Earth. We understand the Laws of Nature and use them for our own
welfare. This is wonderful until…we do it offending Mother Nature in such a way
that she will suffer an irreversible damage or … strike back.
We
can cope successfully with the natural threats against our existence if we
learn and understand our surrounding world, but we must be aware and careful
about the threats we are bringing to Nature as well. Nature cannot defend
herself with advanced technology.
We
are depriving the Earth of natural resources and filling our environment with
“unnatural” substances. This is our Damocles’ sword: threats against our
existence brought by ourselves.
NEXT CHAPTER: