Plagues and Peoples

Nobody comprehends the universe, because it is almost entirely out of sight.  We also can’t see the universe of microorganisms here on Earth, or fully comprehend their powerful influence.  Historian William McNeill learned that disease has played a major role in the human journey, and he wrote a fascinating introduction to our intimate companions, the parasites, in Plagues and Peoples.

All critters eat.  Hosts provide food, and parasites consume it.  Large-bodied parasites, like wolves, are macro-parasites.  Wolves kill their hosts.  Micro-parasites include bacteria, viruses, and small multi-celled organisms.  If they quickly kill their host, the banquet is short.  A more stable strategy is to simply take a free ride on a living host, like the billions of bacteria that inhabit our guts, share our meals, and don’t make us sick.

In healthy ecosystems, stability is the norm.  Species coevolve, which encourages balance, like the dance of oak trees and squirrels, or the foxes and rabbits.  Balance is disturbed by natural disasters, like when an invasion of organic farmers overwhelms an ecosystem with their plows, axes, and enslaved animals.  A farming community is a mob of macro-parasites that weakens or destroys its ecosystem host over time.  When parasites disturb balance, McNeill calls this disease.  “It is not absurd to class the ecological role of humankind in its relationship to other life forms as a disease.”

The ruling classes in civilizations behave like macro-parasites when they siphon nutrients away from the working class hosts that they exploit.  To survive, the elites must keep enough farmers alive to maintain an adequate supply of nutrients.  Elites rely on violence specialists to protect their host collection from other two-legged macro-parasites, like the bloodthirsty civilization across the river.  In this scenario, the worker hosts are suffering from a type of disease (the elites) that is called endemic, because it allows them to survive.

Disease that kills the host is epidemic.  “Looked at from the point of view of other organisms, humankind therefore resembles an acute epidemic disease, whose occasional lapses into less virulent forms of behavior have never yet sufficed to permit any really stable, chronic relationship to establish itself.”

Our chimp and bonobo cousins continue to have a stable relationship with their ecosystem.  Consequently, there are not seven billion of them.  Like them, our pre-human ancestors evolved in a tropical rainforest, a warm and wet ecosystem with immense biodiversity.  This diversity included many, many types of parasites, and they lovingly helped to keep our ancestors in balance.  Life was good.  “The balance between eater and eaten was stable, or nearly so, for long periods of time.”

Then, some too-clever ancestors began fooling around with technology.  With spears, we were able to kill more prey, and foolishly eliminate many of the rival predators that helped keep our numbers in check.  By and by, our ancestors began leaving Africa, moving into cooler and drier climates.  We left behind many tropical parasites, and explored new lands with far fewer parasites.  We suffered less disease.  We moved into new regions as skilled hunters, and encountered game animals that had no fear of us.  With clever new technology, like clothing and huts, our ancestors could sidestep our biological limitations and survive in non-tropical habitats.

Antelope and tsetse flies are unaffected by the sleeping sickness parasites they carry.  Many species of burrowing rodents live with the bubonic plague bacteria harmlessly.  These relationships are old and stable, but a blind date with a new parasite can be fatal.  With the advent of animal domestication, there were many blind dates.  We began living in close proximity to other species, and their parasites, to which we had no immunity.  This gave birth to the deadly new diseases of civilization, and led to a long era of epidemics.

“Most and probably all of the distinctive infectious diseases of civilization transferred to human populations from animal herds.”  Aborigines, who did not enslave herd animals, did not suffer from infectious disease.  The same was true for Native Americans, even those who lived in the densely populated regions of Mexico, Central America, and the Andes.

Humans share many diseases with domesticated animals: poultry (26), rats and mice (32), horses (35), pigs (42), sheep and goats (46), cattle (50), and dogs (65).  In addition to the diseases of civilization are ancient rainforest diseases like malaria and yellow fever, which were introduced to the Americas by the slave trade.

From 500 B.C. to A.D. 1200, as civilizations developed in different regions of Eurasia, each area developed pools of civilized diseases, some of which became quite popular.  India has a wonderful climate for parasites, and it may be where smallpox, cholera, and plague parasites first entered human hosts.  Bubonic plague slammed into a virgin population in the Mediterranean basin.  The plague of Justinian (A.D. 542-543) hit hard, maybe killing 100 million, about half of Europe.

From 1200 to 1500, the isolated disease pools of Eurasia eventually connected with the others, creating one large pool of civilized diseases.  Nomads, like the Mongols, transported parasites back and forth between China and Europe.  Parasites also travelled by ship.  Black Death began in China around 1331.  Between 1200 and 1393, China’s population dropped by half.  The disease arrived in Crimea in 1346, spread across Europe, and killed about a third of the people.  Muslims believed that those killed by the plague were martyrs, chosen by the will of Allah.  They mocked the Christian infidels who successfully limited the spread via quarantines.

Between 1300 and 1700, a number of epidemic diseases became domesticated.  To survive, parasites required a steady supply of new hosts without immunity — these were mostly children.  A population of 500,000 or more was needed to produce enough new hosts to support an ongoing infestation of measles.  If a disease was too virulent, it would eliminate its hosts and die off.  Over time, a number of serial killers softened into childhood diseases, like mumps, smallpox, and measles.

From 1500 to 1700, Old World diseases discovered the New World.  Europeans and their African slaves were walking disease bombs, but they were mostly immune to the parasites they carried.  Native Americans were a virgin population, having no immunity whatsoever to the new parasites, they were blindsided by catastrophic epidemics.  The population of Mexico and Peru dropped 90 percent in 120 years.

Since 1700, science has made great advances in death control (not balanced by equal achievements in birth control).  Vaccinations have been effective in controlling smallpox and polio.  Antibiotics have temporarily provided several decades of relief from a number of infectious parasites.  Sewage treatment and water purification systems have also provided temporary relief, during the bubble of abundant energy.

Industrial society, with its radically unhealthy way of life, has created new diseases of civilization, like cancer and heart disease.  Influenza is a powerful wild card, because it rapidly mutates, sometimes into highly virulent forms.  By the time the vaccines are mass-produced, the pandemic is over.  Many new viral diseases, like Ebola and AIDS, are appearing, as the human swarm meets new and exciting rainforest parasites.

The plague bacterium still lives harmlessly in burrowing rodents and their fleas.  Over the years, it has spread around the world.  By 1940, it was carried by 34 species of burrowing rodents in America, and 35 species of fleas.  By 1975, it was found across the western U.S., and portions of Canada and Mexico.  Black rats are the vector that moves the parasites into humans.  As long as the gas-guzzling garbage trucks keep running regularly, we’ll be safe, maybe.

Modern consumers have had little exposure to epidemic disease, but our elaborate, energy-guzzling systems of death control only provide temporary protection.  Sewage treatment, water purification, effective antibiotics, and industrial agriculture have a limited future in a Peak Energy world.

McNeill, William H., Plagues and Peoples, Anchor Books, New York, 1998.  [1976]

Other reviews of books on health include:  Bird Flu, Epidemics, Health & the Rise of Civilization, The Antibiotic Paradox.

Silent Spring

Silent Spring is a classic, a powerful broadside against synthetic pesticides.  Now, more than fifty years old, the book still packs a solid roundhouse punch.  With one book, one woman enlightened millions and spurred a loud outcry.  One woman inspired big changes.  Many of the pesticides she slammed have been banned or highly restricted.

Following World War II, Americans had big heads.  We had won the war, invented a terrible new weapon, our economy was booming, and life was great!  We succeeded at whatever we tried.  We were giddy with euphoria.  Then, Rachel Carson rolled a hand grenade into our dining rooms.  Suddenly, Sunday dinners at grandma’s looked far less delicious.  What were we eating?  Would it kill us?

During the war, researchers working on chemical warfare agents discovered substances that were highly toxic to insects.  After the war, greedy minds became fascinated by these super-poisons, and visions of big profits danced in their heads.  Synthetic pesticides were toxic to morals, ethics, and foresight.  And so, a new industry was born, and the production of pesticides increased five-fold between 1947 and 1960.

To control the elm bark beetles that caused Dutch elm disease, two to five pounds of DDT were sprayed on elm trees.  This killed the natural predators of the beetles, as well as 90 species of birds, and assorted mammals.  Worms ate the poison leaves, and the robins that ate the poison worms quit reproducing.  Elms kept dying.  More elms survived in places not sprayed.

To control gypsy moths, a million acres a year were sprayed with DDT.  Sprayers were paid by the gallon, not the acre, so some places were sprayed multiple times.  Bees died.  Cows ate DDT grass and produced DDT milk that was consumed by DDT humans.  Regulators did not block the sale of poison milk.  At the end of the expensive project, the gypsy moths returned.

To control fire ants, millions of acres were sprayed with two new poisons: dieldrin and heptachlor, which were far more toxic than DDT.  Newborn calves died after their first drink of milk.  Piglets were born dead.  Opossums, armadillos, raccoons, quail, songbirds, turkeys, livestock, poultry, and pets died.  In the end, there were more ants in Florida than before.

We know little about what these toxins do to the complex microorganisms in healthy topsoil.  Many of them interfere with nitrogen-fixing bacteria, which provide an essential nutrient for all living things.  Some organisms are wiped out, leading to explosions of other organisms.  The chemicals persist in the soil for years, and build up with each new application.  Soil beneath an apple tree can contain 113 pounds (51 kg) of DDT.  Old-fashioned arsenic pesticides keep the soil toxic forever.

Yes, it’s a bummer that all spawning salmon died when New Brunswick’s Miramichi River got sprayed with DDT, while the terrible spruce budworms laughed at the embarrassed entomologists.  When Ontario sprayed to kill blackflies, they wiped out blackfly predators, enabling the fly population to explode 17-fold.  The same thing happened in Florida, where large areas in coastal regions are now uninhabitable because of hordes of pesticide-resistant mosquitoes.

“Resistant” is a keyword in this comedy of errors.  Big Mama Nature routinely produces organisms that are resistant to insecticides, herbicides, fungicides, antibiotics, and antivirals.  We can throw one poison after another at life, and life will become resistant to it.  Winning the war on life is impossible.  Resistance can develop in as little as two months.  The average time is three years.  Insects are reproductive champions, and can promptly refill the land with resistant offspring.  The breeding process in humans is much slower, so it will take us thousands of years to become resistant to pesticides. 

Silent Spring delivered two powerful messages.  It alerted us to the nightmare world of pesticides.  It also turned big floodlights on the incredible incompetence of our experts and regulators.  In 1960, almost everyone was blissfully ignorant about the toxic chemicals in their lives.  In those days, most folks still trusted their elected officials.  They trusted the experts who told them that DDT was harmless, and chlordane was a wonder of scientific genius.  Today, for good reason, we automatically doubt any statements made by leaders or experts because they, too often, have little or no relationship to the full truth.

Carson did not believe that the use of pesticides should be banned entirely, but she did recommend that we shift toward less toxic alternatives, like pyrethins and Bacillus thuringiensis (Bt).  Not surprisingly, malarial mosquitos are becoming resistant to bed nets treated with pyrethin-based insecticides, and many crop pests are now resistant to Bt.

She was fascinated by research in sterilizing male bugs, so that female bugs would not be able to tell the studs from the duds.  Chemo-sterilants were used to render millions of houseflies impotent.  Male gypsy moths found their lovers via sexy scents.  Researchers sprayed this scent all over the place, and were delighted to observe the flying lads falling deeply in love with wood chips that smelled like hot babes.  Ultrasonic sounds could be used to kill blowflies, mealworms, and yellow fever mosquitoes.

About half of the insects called pests are immigrants from foreign lands.  Here, they were not controlled by their natural predators from the old country.  Carson recommended importing the predators and parasites of notorious immigrant pests.  Moving organisms from one region to another is a mistake that has often led to unintended disasters, like the rabbits of Australia, the potatoes of Ireland, smallpox, and so on.  She thought that it was OK for humans to try to sit in the ecosystem’s driver’s seat.

Carson was fighting breast cancer as she finished her book, and she died in 1964, two years after it was published.  If she had lived longer, I think she would have recognized the serious shortcomings of the anthropocentric worldview of her era.  Living like the masters of the planet has been a reliable recipe for countless catastrophes, and it’s the core reason why seven billion people are standing on very thin ice today.

Ecological thinking is the antidote.  Forget control — adapt!  Carson was intrigued by the brilliant rascal Paul Shepard, who could have exorcised her anthropocentric demons, had she lived longer.  She quoted Shepard, who summed it up nicely: “Why should we tolerate a diet of weak poisons, a home in insipid surroundings, a circle of acquaintances who are not quite our enemies, the noise of motors with just enough relief to prevent insanity?  Why would want to live in a world which is just not quite fatal?”

PS: Locust is the story of how humans, for once, actually succeeded in driving a major crop-destroying insect pest into extinction — unintentionally — by simply living like civilized people. 

Carson, Rachel, Silent Spring — Fortieth Anniversary Edition, Houghton Mifflin Company, New York, 2002.

Overshoot

William Catton’s book, Overshoot, describes the process by which most modern societies have achieved overshoot — a population in excess of the permanent carrying capacity of the habitat.  It examines the long human saga, and reveals embarrassing failures of foresight that make our big brains wince and blush.  Catton drives an iron stake through the heart of our goofy worldview — the myths, fantasies, and illusions of progress.  Readers are served a generous full strength dose of ecological reality with no sugar coating.

Humans evolved to thrive in a tropical wilderness.  In the early days, we lived lightly, like bonobos, in a simple manner that supported a modest population density.  As the millennia passed, we learned how to increase carrying capacity by adopting ever-more-clever technology, like spears, bows and arrows, and fire — better tools, more food.  This was a blind leap into the unknown.  It pushed us out of evolution’s safety net, and required us to create cultural safety nets, based on enlightened self-restraint.  Our path became slippery.

Much later, we slipped into soil mining — agriculture — which sent our carrying capacity into the stratosphere — temporarily.  Topsoil is created over geological time.  From a human timeframe, it is a nonrenewable resource.  Soil mining often leads to water mining and forest mining.  It has a long history of spurring population growth, bloody conflict, and permanent damage to ecosystems.

Then, we slipped into metal making, and invented many new tools for raising carrying capacity even higher.  This was a big fork in the path.  Up to this point, we increased carrying capacity by takeover, expanding into new habitat and pushing out other species.  Now, we added drawdown to the game, by tapping into finite nonrenewable resources, and becoming heavily addicted to them.

When communities lived with enlightened self-restraint, salmon and bison could be renewable sources of food for tens of thousands of years, or more.  Iron, oil, and topsoil are not renewable.  Their extraction does not contribute to the real carrying capacity of the habitat.  What they provide is phantom carrying capacity, a boost that can only be temporary.

A habitat’s carrying capacity is limited by the least abundant necessity.  The limiting factor was usually food, but it can also be water or oil.  Writing in the late 1970s, Catton perceived that 90 percent of humankind was dependent for survival on phantom carrying capacity.  Today, that figure is certainly higher, with billions of people dependent on oil-powered agriculture and market systems.  As the rate of oil extraction declines in the coming decades, there will be many growling tummies.

Columbus alerted Europeans to the existence of an unknown hemisphere, the Americas.  This “New World” was fully occupied by Stone Age nations that survived by low-tech hunting, fishing, foraging, and organic soil mining.  They had no wheels, metal tools, or domesticated livestock.  European colonists, with their state of the art technology, vigorously converted wilderness into private property devoted to the production of food and commodities for humans.  This greatly expanded the carrying capacity of the Americas (for humans).  Colonists exported lots of food to Europe, and population exploded on both sides of the Atlantic.

A bit later, we developed a tragic addiction to fossil fuels, which led to the Industrial Revolution.  We began extracting solar energy that had been safely stored underground for millions of years.  Cool new machines allowed us to expand cropland, increase farm productivity, and keep growing numbers of people well fed.  The population of hunter-gatherers grew 0.09% per generation.  With the shift to agriculture, population grew 0.78% per generation.  Since 1865, it’s growing 27.5% per generation.

For four centuries, much of the world experienced a ridiculously abnormal era of innovation, growth, and excess — the Age of Exuberance.  This created a state of mind that perceived high waste living as normal, and expected it continue forever.  We were proud that our children would be able to live even more destructively than we could.  Our glorious leaders worked tirelessly to increase drawdown and worsen overshoot.

We have no limits.  We’ll grow like crazy until the sun burns out.  This is known as the cornucopian paradigm.  Cornucopians hallucinate that withdrawals from finite nonrenewable savings are income, and that wealth can be increased by withdrawing even more nonrenewable savings.  Cornucopians proudly refer to overshoot as progress.  Ecology, on the other hand, insists that our ability to survive above carrying capacity, in overshoot, can only be temporary.  We can refuse to believe in limits, but limits don’t care if we believe in them.

The Age of Exuberance was brought to an end by the oil shocks of the 1970s.  Our poor children now have a bleak future, a sickening descent into primitive barbarism — no SUVs, ATVs, RVs, PWCs, or McMansions.  It was fun having the wonders of industrial society, like bicycles, metal pots, books, and running water.  But these luxuries were provided by a system that has been surviving for 200 years on an exponential drawdown of nonrenewable resources.  It’s a way of life that survives by burning up posterity’s savings.  Catton warned us, “It was thus becoming apparent that nature must, in the not far distant future, institute bankruptcy proceedings against industrial civilization, and perhaps against the standing crop of human flesh.”

Sadly, the consumer hordes can’t wrap their heads around the notion that the Age of Exuberance is over.  Yes, things are a bit rough now, but recovery is just around the corner, probably tomorrow.  The crazy cornucopian pipedream has become the primary worldview in most societies.  It is still injected into the brains of every student, numbing the lobes related to enlightened self-restraint, often permanently.

We become anxious and angry as we slip and slide into more and more limits.  Catton noted that a worrisome reaction to this is to blame someone, to identify scapegoats, hate them, and kill them — but this is pointless.  “The end of exuberance was the summary result of all our separate and innocent decisions to have a baby, to trade a horse for a tractor, to avoid illness by getting vaccinated, to move from a farm to a city, to live in a heated home, to buy a family automobile and not depend on public transit, to specialize, exchange, and thereby prosper.”

While Catton was writing, 40 years ago, a new paradigm was beginning to appear on the radar — the ecological paradigm.  This rational mindset made it easy to understand our predicament, and to envision intelligent responses, but probably not brilliant solutions.  Society is not rushing to embrace the ecological paradigm, because any mention of limits is still pure heresy to the dominant paradigm.

Ecology is not titillating infantile twaddle created by big city marketing nitwits trying to sell you the keys to a treadmill way of life.  It’s as real as life and death.  In the game of ecology, there is no “get out of overshoot free” card.  There is no undo command.  The cost of overshoot is die-off, an unpleasant return to carrying capacity.  After the fever comes the healing.  This is an essential book for animals younger than 100 years old.

Catton, William R., Overshoot — The Ecological Basis of Revolutionary Change, University of Illinois Press, Urbana, 1980.