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.