Research Papers by Dr. Laina Farhat-Holzman

Climate Change, Volcanoes, and Plagues--the New Tools of History
Good Times.  Thursday, January 23, 2003
Climate Change, Volcanoes, and Plagues--the New Tools of History by Laina Farhat-Holzman For Good Times, January 29, 2003

The study of history used to be primarily the study of kings, wars, and great men. But that is the old stuff. A whole new group of historians has emerged in the past couple of centuries who are looking at history differently. Rather than just concentrating on the actions of great men, (a few) great women, and wars, they are going for the big picture. They are looking at the role of disease and plagues in affecting history, the effects of oceanic currents and desert winds on long-term climate change, and the effects of catastrophic events--objects from space or massive volcanic eruptions--on the rise and fall of empires and peoples. This is fascinating new material in which history and a variety of sciences intersect.

"Nuclear Winter?" Scientists today are looking with interest and concern at the growing activity of volcanos around the world. Apparently this has happened before during human history, and of course, much more before we were around. What we have not until now understood is these events have had an enormous affect on governments and religions. One work that is a must-read is David Keys' Catastrophe: A Quest for the Origins of the Modern World (1999). Keys has written the ultimate historic detective story and takes us through his investigation, and concludes with a cautionary look into the future.

The story is that in 535 AD, something happened that was the natural equivalent of what scientists fear would befall the world's climate in the event of nuclear war: the so-called "nuclear winter." According to David Keys: "In that appalling potential future disaster, hydrogen bomb explosions would force vast quantities of pulverized debris, dust, and temporarily vaporized earth up into the atmosphere. There, this nuclear pollution would form a barrier which would prevent much of the sun's light and heat from reaching the ground. Temperatures would fall, the world's climate system would be thrown into chaos, and famine followed by epidemics would begin to rage."

"The mid-sixth-century climatic catastrophe displayed all the hallmarks of nuclear winter. But obviously there were no H--bombs in the first millennium A.D. So what was the culprit?"

With this opening, Keys lays out a historic mystery story that uses the tools of good modern historians: government records, journals, epidemiology, climatology, tree-ring and ice core samples, and makes this all relevant to the global changes that we are undergoing today. Taking the mysterious global event that affected climate, animal and insect life, and human behavior as the trigger for a catastrophe, Keys shows how the ancient world died and the modern world began. It lost its old form of governance (Roman), its old religion (Paganism), and whole peoples were replaced by newcomers from Asia. Keys tells us: "...climatic catastrophe was translated into massive political and religious change through four key interrelated factors: climate, migration, disease, and religion." Just as in Europe, the Middle East and the Orient had experienced massive geopolitical change in the century following the climatic disasters of the 530s; so, too, did the Americas. In Mesoamerica and the Andes, there was a total geopolitical realignment, driven ultimately by the engine of climatic change, which is the most reasonable explanation I have heard for the desertion of the huge Mesoamerican city of Teotihuacan. When a city of perhaps one million people empties practically overnight, something draconian must have happened. A prolongued drought lasting decades would certainly do the trick. In addition, people could lose faith in the gods they had trusted to protect them. Archaeologists have found mounds of violently broken images of the gods and goddesses. They have also found wall paintings that had grown increasingly warlike and savage. Could such a thing happen today? Does this also explain the disappearance of the mysterious cliff dwellers in our own Four Courners region (where Arizona and New Mexico meet)?

Keys takes us through the records of the late Roman Empire, the barbarian invasions that brought it down, and transformed Rome from the greatest metropolis in the world of its time to a miserable Medieval town trying to survive in a malerial swamp. The barbarians (in one instance, Slavs) replaced entire ancient populations, and before they were brought into the Christian fold, they terrorized Europe. This is a frightening story. (Plague plays a role here too, which I will address in another section of this article.)

Keys has us visit Yemen, a wretched backwater today that is in the news only because it is a nexus of terrorist activity and the homeland of Osama bin Laden. In the 6th century, it was a country of substance and considerable wealth. But after 535 AD, something changed. The first major outbreak of bubonic plague broke out there and traveled through all the sea lanes and trade routes, killing off sometimes half the population. What was it that changed the climate, caused a population explosion of a certain kind of rodent carrying a certain kind of fleas? And did this mechanism work in Central Asia also, providing more grassland for the horsemen living there, which in turn, caused them to have a population explosion? Historians know more about the later attack of bubonic plague in the 13th century than they do about this earlier bout, but the mechanisms are the same. What happens to a society that loses up to half its adult population? What is happening to Africa today? We have been there before.

The last section of the book explores what Keys thinks (with good evidence) what happened. Was it a collision with a comet? Siberia had such an event (apparently a piece of a comet) in 1908, that set off hundreds of miles of forest fires. Also, there is evidence that one enormous collision off Yucatan may have triggered the extinction of the dinosaurs. But this 6th century event does not seem to have been from outer space.

There is evidence for a huge volcanic eruption of Mr. Tuba in Java, one so huge that it split the island in two. The sound of it was heard a thousand miles away in China (and duly noted in court journals), and there was a rain of ash that traveled even further. This was followed by months of little sunlight globally, untoward climatic events, such as snow in August in southern China, and droughts and floods in areas not expecting them -- a perfect environment for gestating plagues and barbarian invasions, as well as loss of confidence in government and religion. Keys ends his book with a speculation on potential global catastrophes tomorrow and what we may need to know to protect ourselves. There is evidence that we are entering a new era of geothermal activity, even one of which could create massive dislocations as we have seen before. Third World overpopulation, malnutrition, and new diseases, as we can see in Africa and India today, are already positioning such people as vulnerable to chaos. The developed world is in a much better condition to handle such a catastrophe, but we will have to deal with a desperate Third World exodus.

Taking History Global Keys is the latest of the new historians. One of the older ones, who wrote and taught in the mid-950s, was William McNeill, University of Chicago, who argued that it is ridiculous to consider Europe without Asia. Eurasia is one single land mass, and what happens in one end has always had ramifications in the other end. He taught Eurasian history, the great panorama of interactions between the settled and the migratory peoples (the farmers and herders), which later evolved into empires taken down by barbarian invasions. Civilization (meaning urban systems) has always been threatened by, or tried to dominate, peasants and marauding tribes. That age-old struggle is going on today in Pakistan, Afghanistan, and Central Africa. Like the round earth, history is cyclical, not really linear. We are once more dealing with developed civilizations under attack by some new barbarians, waving the banner of militant religion William McNeill followed up in his inter-continental view of history by writing Plagues and Peoples (1976), a history of successive waves of plagues that have been with us since the domestication of animals. Many of our diseases have migrated from animal to human hosts--including smallpox, as one of the first, and now AIDS, as the most recent. This is still a human issue, and we are still keeping only one step ahead of calamity. Plagues and Peoples is a fascinating read, and the story of the Black Death--a disease that traveled from Asia to Europe and killed from 1/2 to 1/3 of the Old World's population--has never been better told. It may be appropriate to read this today to prepare ourselves for our own bouts with modern plagues--both natural (AIDS) and man-induced (biological warfare).

We now also know that plagues are connected with climate change. Too much or too little rain can spur insect and rodent growth which can bring disease to human beings. Prolongued drought or drastic changes in temperature can bring crop failure, famine, and can make humans vulnerable to diseases they might otherwise resist. Today's global warming is giving a great boost to malarial mosquitos, and scientists are noticing the migration northward of tropical diseases. What we are learning from all of this is the interconnection of all life with the planet's changes and even relationships within our planetary system (commets, for example).

McNeill notes the connection between disease and religion. One of the major reasons for the conversion of Roman and Greek pagans to Christianity has to do with Christian hospitals. The Pagan Romans had a horror of blood and disease, which the early Christians did not. They ministered to the sick, and earned their gratitude. Does this make you think about missionary hospitals around the world today and why Fundamentalist Muslims are beginning to target these institutions?

El Ninos, past and present Today scientists are beginning to understand the complexities of how the planet's oceans, air, and climate interact. Brian Fagan's latest work, Floods, Famines, and Emperors: El Nino and the Fate of Civilizations (1999), addresses this issue.

Fagan has written extensively on pre-Columbian history, most of which depends upon the work of archaeology because New World cultures did not have much by way of written records. He has also spent time in Egypt and Mesopotamia in archaeology digs, which provided him with a good comparison with the New World societies that he explored. I used his book Kingdoms of Jade, Kingdoms of Gold, as the best and most accessible text on Native American empires for an undergraduate World History course.

His latest book goes beyond archaeology and introduces us to the great global climatic systems that are increasingly affecting our lives. Before we had a global civilization, it was difficult for people in one part of the world to know what was going on in another part. A volcanic eruption in Java was the unknown cause for several years of no summer (and famine) in northern Europe. Nor did people in India or Africa, suffering from failure of their Monsoons to arrive, know anything about the great oceanic cycles that we have now named "El Nino" or "La Nina." Our ancestors, when confronted with climatic disasters, were compelled to attribute them to the will of the gods--or, as in today's Central African Republic, to the malevolence of witches.

Fagan provides an exceedingly useful and fascinating overview of the oceanic effects on climate, global warming, global cooling, and how these great natural systems have shaped human history. Empires have risen and collapsed, largely because of relatively rapid changes of climate caused either by oceanic systems, the oscillation of the earth, or (as Keys charts) from catastrophic volcanic activities. It doesn't take much to propel a society that is failing into collapse. A decade or two of drought can do it.

Fagan begins his book with our fairly recent awareness of the El Nino cycles which affected world climate just a few years ago. Disastrous floods in South America and California and equally disastrous droughts in Africa and India forced us to see this oceanic system as global. He then shows how a great industry in South America, the Guano business (sea bird droppings that were exceedingly effective as fertilizers) boomed and then collapsed when the oceanic currents warmed and then cooled. Economies are not just in the hands of their human makers; Nature can also make or break them.

He then charts the effects of the oceanic warming and cooling on the atmosphere and on winds. "We live in a world of seething air, which flows around us in a state of constant change," he tells us. We take for granted the hurricanes, tropical cyclones, searing desert winds, and months of steady trade winds. These atmospheric systems constantly change and have an effect on the success or the failures of our enterprises and indeed, on our very lives themselves.

The Northern Atlantic Oscillation is a system that governs the currents of water, warm and cold, that travel from the tropics to northern Europe. Without the Gulf Stream, that current of warm water, Northern Europe would have the climate of Siberia. If anything happens to that current, Europe may again have such a climate. Periodically the current shifts, and we see violent weather incidents. We could see this happen now.

The second part of his book charts the effects of El Ninos in antiquity. Fagan looks at the warming phase that launched civilization, and those climatic catastrophes that brought down Pharaohs in Egypt, the Moche Lords on the Pacific coast of Peru, the classic Maya collapse, and the disappearance of the Old Ones (the great Pueblo civilization in the American southwest).

His observations of the correlation between the Egyptian Old Kingdom Nile flood rates and political thriving or collapse provides a standard by which to observe modern Egypt. The Nile flood rates are at their lowest today, and their population at its highest. Can disaster be far behind?

He tells us: "The NAO [North Atlantic Oscillations] and ENSO [El Nino Southern Oscillations] are two parts of a single, complex world climatic system. This climatic system oscillates on many time scales, confronting humanity with unusual and challenging weather at every season of the year. These oscillations--hot and cold, wet and dry, have always forced humans to adapt to rapid climatic change."

He notes that when we were few in number (population explosion buffs take note), we could move away and save ourselves. When we are many and married to our locale, we lack the flexibility to meet these challenges.

The Sahara Desert winds are one other great engine in the global climate system. These winds interact with other air and water systems of the planet, affecting human life. Today's famines in Africa result from climate changes, desertification, and an exploding population living already at subsistence level. In such disasters, religious Pied Pipers move in and reap violent converts. It is already happening.

The last part of his book examines climate change and the stream of time. He looks at the Little Ice Age during Europe's Medieval period, the droughts that followed the plow, El Ninos that shook the world, and his conclusions on the fate of civilizations.

Fagan does not attribute global warming exclusively to human activity. The value of this book is to show us the interaction of climate changes or catastrophic events with human responses--both wise and foolish. We may be hastening the advent of global warming, but the system is much bigger than we are. Nonetheless, knowledge of how these systems work and what we can do to survive their worst depredations is essential to our survival.

Obviously the population explosion that has burgeoned over the past 400 years has consequences. Fagan notes that those underdeveloped regions in which too many people live too close to disaster anyway will, and are, suffering from global climate changes right now. If enough people heed this message, we could prioritize and mandate population control globally. We either do it voluntarily or El Nino will do it for us.

Other New Areas of History A number of historians are working in prehistory. Almost every day, it seems, we learn more about the amazing accomplishments of our most ancient ancestors. A colleague of mine, Stedman Noble, has been doing research on the sea-going capability of people much earlier than conventional history ever guessed. He is working on growing evidence that these very early sea people are somehow connected to the mysterious stone megaliths (such as Stonehenge) all over the world. While this research is still in its infancy, it is apparent that we humans were global travelers long before the discovery of the New World by Columbus. Two more scholars who have plumbed the dim recesses of earliest human history are Jared Diamond (Guns, Germs, and Steel, 1998), and Bryan Sykes (The Seven Daughters of Eve, 2001). Diamond attributed the success of Eurasia in its conquest of the rest of the world more to luck than virtue. The Eurasian land mass had a confluence of suitable edible grains and large domesticable animals that was capable of producing civilizations of power and wealth. The New World and Sub-Saharan Africa did not have these benefits until conquest and colonization by Eurasians. (By Eurasians, he includes Japan and China, India, the Middle East, the Mediterranean, and Europe.)

DNA and Human Evolution Bryan Sykes, a British expert on DNA and human evolution, made a discovery whose scientific and cultural ramifications have turned past knowledge on its ear. He has proven through painstaking research that almost all people of native European descent, no matter where they now live in the world, can trace their ancestry back to one of seven women who were descendants of the original mother of us all, the first female (named by scientists "Eve"), who was homo sapiens and lived in Africa. Something--probably major climate change--drove our ancestors out of Africa and the newest thinking is that this one small group peopled the world. All of the rival groups of human-like creatures, including the Neanderthals, eventually failed. We now know this because none of their genetic material is found in modern humans anywhere on earth, whereas all of us bear the DNA of that original mother.

Sykes is a professor of Human Genetics at Oxford University and is a science adviser for the British Parliament. He and his research team, over the last ten years, have compiled the most complete DNA family tree of our species ever done.

What is fascinating in this book (Sykes is a wonderful writer) are the stories that we can imagine about the lives of those who preceded us. DNA studies (focussing on the maternal line) in the British Isles have shown that while we all descend from one human line, no matter how different we may look, and that our ancestors have traveled the globe. Sykes has found remote DNA evidence of connection to a Siberian maternal line in people living even in isolated islands off the Scottish coast. Even a woman living in a village in England has a DNA connection to Africa that is several thousand years old. Was that mother a Roman slave brought to Britain, perhaps? There are no Pure Bloods among us, and despite racist claims, there is only one thoroughly mixed human race. The New Biological Sciences Science is just now beginning to take on the underlying causes for why human beings behave as they do--a range that runs from criminality to genius and altruism. Until now, only great literature has speculated into why we are as we are (think of Shakespeare's Macbeth or King Lear, or Sophocles' Antigone--all three effectively dealing with human propensities for good or evil).

Now, with the Genome Project's mapping completed, biologists are beginning to identify where in the genes certain traits may be found. We are learning more about mental illness, about those aspects of antisocial behavior not created by environment, and about propensity to diseases that may lie within our genes. I cannot imagine that these discoveries will not turn our legal and religious systems on their ears. How can we punish someone for behavior that was programmed rather than a deliberate choice? What is guilt and what is innocence?

Keep an eye on the new historians who are leading us into worlds we dreamt not of and explanations that illuminate what was dark and mysterious. ---------- 3436 words

Dr. Laina Farhat-Holzman is a historian, lecturer, and writer. Her new book: God's Law or Man's Law--The Fundamentalist Challenge to Secular Rule, is available at local bookstores and at You may contact her at or visit her website at