Floods and Plagues: New Lessons From the Old Testament

The late spring/early summer of 2010 was much wetter than normal in West Central Illinois. The sewer backed up into my basement while I was out of town. I returned home to an unmistakable smell and dismissed it as a “freak event” while I cleaned it up. A couple weeks later, I was home during a particularly Biblical downpour. The sewer began to back up again and, despite my best efforts to staunch the flow with a plunger, sewage poured out of my basement toilet with a ferocity that was reminiscent of the elevator scene in Stanley Kubrick's “The Shining” except in sepia-tone. When I called the city to remind them that I paid for sewage to be taken away from my house not delivered to it, I was told that May and June of 2010 were unusually wet and that the city's old-school combined system could not handle it (newer systems have separate pipes for sewage and storm run-off). The voice on the phone told me that we had received 24″ of rain in May and June. I checked the weather for 2010: In May we received 11.90″ and June 11.78″. I checked the climate records: The long term average for May was 4.27″ and the previous record for the month 11.29″ recorded in 1908. The long term average for June was 4.26″ and the previous monthly record of 13.97″ had been set in 1902. In other words, in two consecutive months we had nearly equaled or exceeded all time records, which were set over a century ago! This gave me something to think about as I squee-geed, shop-vacced, and Cloroxed my basement for the second time in as many weeks: How does a culture or civilization respond when all of its assumptions about the world (and the resulting necessary embodiment in infrastructure) no longer apply?


The instant flood and prospect of illness presented by the excrement got me thinking about two classic tales in the Old Testament: The Noahic Flood from Genesis and the Ten Plagues of Egypt from Exodus. As a Biologist I get some grief for being a scientist and for Science and Religion being incompatible. On the one hand, science is not known for supporting supernatural explanations of any kind. On the other hand, naturalistic accounts could explain some phenomena that appeared to be supernatural to people of the Old Testament.

I was brought up by a completely lapsed Southern Baptist, thoroughly agnostic father and Bahá'í mother (who was herself the product of a non-practicing Jewish father and non-practicing Catholic mother). Not surprisingly, I decided at a pretty young age that everything in the Abrahamic tradition could be read metaphorically rather than strictly literally, so I was amazed when I began to realize there was a cottage industry of scientists who tried to explain things in the Bible using modern methods and methodologies. If for no other reason than that I could tell people that science supported some of the things in the Bible (and that therefore they were not completely opposed to each other), I began to save some articles and make some notes.

In the late 1990's a pair of geologists published a book that explained the Noahic flood as the flooding of land around the Black Sea as the Mediterranean rose from melting glacial ice sheets and spilled over the Bosporus and offered some compelling evidence to support their ideas. At about the same time, a pair of epidemiologists (Marr and Malloy, 1996) arrived at a plausible epidemiological explanation of the 10 plagues of Egypt. I would like to explore both of these hypotheses a bit and put together my own synthesis.


As the Pleistocene ended about 12,000 years ago, the great ice sheets that covered much of the northern continents retreated and their run-off made the ocean rise hundreds of feet. That this happened globally probably explains why flood myths tend to be universal (Wilson, 2001). Some of these past floods were truly epic. Nearly 12,000 years ago, much of the Columbia River Gorge may have been carved out in about a week, when a glacial ice dam failed, allowing 2,000 feet deep Glacial Lake Missoula to empty at a flow rate of 9.46 cubic miles per hour, which is about 50 to 60 times the flow of the Amazon River (Gould 1980, Glacial Lake Missoula)! The scale of this event was so far beyond the pale, that it was initially dismissed as being incompatible with the Uniformitarianism and Gradualism that are the bedrock (pun intended!) assumptions of modern Geology.

The Noahic flood may be more familiar to many people. Two geologists (Ryan and Pittman, 1998), argued that it resulted from the rising waters of the Mediterranean Sea overflowing the Bosporus and filling the freshwater Black Sea with saltwater. By some estimates, a day's flow over the giant falls at the Bosporus would have a equalled up to a year's flow over Niagara! As the water rose at about a foot a day, the flooding of the low-lying area around the Black Sea led to a diaspora that spread agriculture, along with tales of a great flood, all over Eurasia.


We tend to present science as a monolithic enterprise in which the scientific method is solely practiced. Double-blind experiments with treatments, controls, and replication are the “Gold Standard,” and anything else is regarded as lesser or even suspect. Unfortunately, the real world is rarely so accommodating and it is just not ethical to infect half of a population with something nasty while the other half gets a placebo. Epidemiologists have assembled their own set of tools for practicing science within their set of constraints.


Focusing on the sequence and timing of events, and the specificity of symptoms and their causes, Marr and Malloy (1996) present the following argument: The Egyptians at that time were a river and agricultural people. A freshwater “red tide” caused by the aptly-named dinoflagellate Pfisteria piscimorte (Plague 1: Blood) killed fish (a major source of dietary protein) and forced frogs onto the land (Plague 2: Frogs), where they died, and thus were no longer around to control insect populations. Instead, their carcasses provided plenty of food for insect larvae that transformed into the adults of Plague 3: Lice, and Plague 4: Flies. Marr and Malloy believe these insects were Culicoides biting midges (“no-see-ums”) and Stomoxys stable flies, both efficient vectors for orbivirus infections that resulted in the death of livestock (Plague 5), and bacterial infections that caused Boils (Plague 6), both of which further reduced dietary protein and left fewer animals and people to practice agriculture with. Hail (Plague 7) killed people, animals, and lodged grain, further reducing food stocks. Solitary locusts, responding to crowding and stress, morphed into migratory swarms and devoured much of what grain remained (Plague 8: Locusts). Sandstorms, likely khamsin (hot Saharan winds) or sobaa (severe, multiday-long storms) caused the Darkness of Plague 9, and covered the wet grain with warm dust and locust feces, which promoted mold growth and mycotoxin production that led to the Death of the Firstborn: Plague 10 (or using a different translation, the death of first fruits or shoots). Whether this final plague involved killing children or new crops is not so important as the idea that this powerful civilization suddenly had no future. The assumptions behind their relationships to the water and land no longer held.


A common theme that ties together The Great Flood and The Ten Plagues is Global Climate Change. As the earth began warming near the end of the Pleistocene; ice sheets melted and the sea level rose, inundating coastlines around the world and some inland areas like those around the Black Sea. Another major prediction of global warming is that extreme weather will become more severe and more frequent. A look at global temperature measurements show a slight bump between 2000BCE and 1000BCE. The Ten Plagues are thought by many scholars to have occurred between 1500-1200 BCE. Warming could have triggered the Red Tide that then precipitated the next five plagues. Warming could also have increased the frequency of severe local weather like hailstorms, and sandstorms (Plagues 7 & 9), which initiated the plagues of Locusts and the Death of the Firstborn. Starvation and disease amplify each other's effects with the result that 1 + 1 = 5.


The end result of the Ten Plagues, was that the Israelite slaves were freed by the pharoah and subsequently fled Egypt. Slavery is not something that we tend to associate with our lives today, but in 21st Century North America we each rely upon 100 to 200 “energy slaves” in the form of fossil fuels for our daily activities. Like it or not, whether we voted for Palin or Obama, we are all pharoahs or plantation owners in that we rely on energy that is not from our own bodies for heating, cooking, manufacturing, and transport. Certainly, depending on black gold is preferable to exploiting black bodies, but is it in our best interests to be so inextricably entwined with fossil fuels? Peak oil and global warming suggest no.


Is oil our slave or are we its slave? That America has spent trillions of dollars over the last decades supporting a military that ensures safe passage of oil through the Persian Gulf suggests the latter. Just as the Egyptians depended on the flow of the Nile to water crops and slake the thirst of animals and human laborers, we depend on an ever increasing river of oil arriving at our shores from all over the planet to supply energy and chemical feedstocks for our civilization.

Of course, the real threat may be in the Carbon dioxide that is released by burning fossil fuels. Just as Abraham Lincoln and Stephen A. Douglas debated the future of human slavery 152 years ago, a few blocks from where I am writing this, we need to seriously address “energy slavery” and its consequences today. Unfortunately, I don't yet see either the political will or insight among any of our leaders.

A new exhibit about human origins at the Smithsonian Institution in Washington, D.C. declares “Humans Evolved in Response to a Changing World,” and seems by extension to imply that “we've done it before, we'll do it again,” while never discussing the role fossil fuels play in our current situation, or the role mass mortality plays in making natural selection work. Responding to climate change may be one of the factors that drove human evolution, but our domination of the planet has arisen during a period of relative climatic stability that we are in the process of pushing ourselves out of. Even if the average climate stays the same, the extremes will become even more extreme.

Not surprisingly, David H. Koch, billionaire oil tycoon, and climate change denier, underwrote the exhibit just as he underwrote the Mercatus Center at George Mason University, The Cato Institute, Americans for Prosperity, and Tea Partiers, among others (Mayer, 2010). It's his money and he can do what he wants with it, but it seems to me that one individual having so much influence undermines the concept of one man, one vote that underpins our democracy. One argument made by deniers is similar to that made by tobacco companies: We can't do a proper experiment, therefore we can never really be sure about the causal links between and X and Y (substitute tobacco and lung cancer or fossil fuel consumption and global climate change). Against that kind of money and argument, all I can do is point to the geological and historical records, and the epidemiology of Marr and Malloy, which suggest that we have already participated in some global warming experiments with severe results. The great flood chronicles the global rise in sea level that accompanied the end of the last Ice Age, from which refugees fled en masse. Exodus may be in fact describing the first epidemics and epizootics that would be expected when increasing population size mixes with a bit of climatic warming.

I am using science to attempt to confirm and explicate a literal reading of parts of The Old Testament, but one that implicates climate change as a causative agent for floods and plagues. Followers of the Abrahamic tradition could agree with the details of a literal reading but conclude that the causative agent was an angry God for the Great Flood, and one who later came down on the side of the enslaved Israelites by ensuring their emancipation and safe passage to freedom. Recognizing God's omnipotence affirms our smallness. With nearly seven billion people, some of whom have huge ecological footprints, that smallness is questionable today. Positing an all-powerful God may also have the effect of relieving us of any individual or collective responsibility for our actions. Many of the same people who believe in an all-powerful God also deny climate change, yet over the last century and a half, we have in fact achieved God-like power with our ability to change the earth's climate through our activities.

With great power comes great responsibility. Unfortunately, we have not fully owned-up to this responsibility. At the time of Exodus, an estimated 2.5 million people lived along the Nile and environs. Today a large fraction of the nearly 7 billion people live on or near coastlines or rivers. The rest will also be increasingly susceptible to floods and plagues that will be realized in a warming world. Recent events in Haiti and Pakistan may well be a preview of coming attractions. The effects on other species will likely be catastrophic as well. Minimizing the causes and effects of these changes will likely be the central challenge to humanity in the 21st Century.

As for my basement, the city informed me that a check valve installed on the line between the house and the sewer main would prevent future sewer back-ups. It will not be cheap, but it may be the first serious external cost of global change that I have to pay for directly. I hope it will be the last, but don't think it will be.


Stephen J. Gould. 1980. The Great Scablands Debate. in The Panda's Thumb: More Essays in Natural History. Norton. New York.

John S. Marr and Curtis D. Malloy. 1996. Epidemiologic Analysis of the Ten Plagues of Egypt. Cadaceus. (12):1: 7-24.

Jane Mayer. 2010. Covert Operations: The Billionaires Who Are Waging A War Against Obama. The New Yorker. August 30.

William Ryan and Walter Pitman. 1998. Noah’s Flood: The New Scientific Ideas About the Event that Changed History. Simon and Schuster, New York.

Ian Wilson. 2001. Before the Flood: The Biblical Flood as a Real Event and How It Changed the Course of Civilization. St. Martin's Press, New York.