THE SWORD OF DAMOCLES AND
THE BIOSPHERE
John Cairns, Jr.
University Distinguished Professor of Environmental Biology Emeritus
Department of Biological Sciences
Virginia Polytechnic Institute and State University
Blacksburg, Virginia 24061, U.S.A.
January 2011
Dionysius (II) was a fourth century B.C. tyrant of Syracuse, a city in Magna Graecia,
the Greek area of southern Italy. To all appearances Dionysius was very rich and comfortable,
with all the luxuries money could buy, tasteful clothing and jewelry, and delectable food. He
even had court flatterers (adsentatores) to inflate his ego. One of the ingratiators was the
court sycophant, Damocles. Damocles used to make comments to the king about his wealth
and luxurious life. One day when Damocles complimented the tyrant on his abundance and
power, Dionysius turned to Damocles and said, “If you think I’m so lucky, how would you like to
try out my life?”
Damocles readily agreed, and so Dionysius ordered everything to be prepared for
Damocles to experience what life as Dionysius was like. Damocles was enjoying himself
immensely . . . until he noticed a sharp sword hovering over his head, that was suspended
from the ceiling by a horse hair. This, the tyrant explained to Damocles, was what life as ruler
was really like.
Damocles, alarmed, quickly revised his idea of what made up the good life, and
asked to be excused. He then eagerly returned to his poor, but safer life
(http://ancienthistory.about.com/od/ciceroworkslatin/f/DamoclesSword.htm).
 The Roman orator Cicero used this parable to describe a sense of foreboding, which could result in a defining
moment in a person’s life.
THE SWORD OF DAMOCLES HANGING BY A
THREAD OVER HUMANKIND IS DAMAGE TO THE
PRESENT BIOSPHERE, WHICH IS BOTH A LIFE SUPPORT
SYSTEM AND THE SOURCE OF RESOURCES THAT FUEL
THE HUMAN ECONOMY.
 Although I have been an environmental biologist since 1948, I had no sense of foreboding
until 1988 when I co-chaired the conference “On Global Warming: Atmospheric Carbon
Dioxide and Global Warming.”
 Since 1988, my sense of foreboding about the deleterious consequences of climate change
and biospheric damage for humankind has increased markedly.
 I have no foreboding about the future of life on Earth, at least until the sun begins to die.
LIFE ON EARTH BEGAN APPROXIMATELY 3.5
BILLION YEARS AGO. SINCE THEN, FIVE GREAT
EXTINCTIONS OF SPECIES HAS OCCURRED. FROM THE
SURVIVING SPECIES, EVOLUTION HAS RESTORED
BIODIVERSITY OVER SUBSTANIAL SPANS OF TIME.
 After each extinction, the new array of species has always been markedly
different from past arrays.
 The sixth biosphere (the present one) is now experiencing a marked reduction in
species caused by human-related activities.
 Since species are the basic components of biospheres, neither structure nor
function of the next biosphere can be predicted.
BY NURTURING THE PRESENT BIOSPHERE,
ITS LIFE COULD PROBABLY BE PROLONGED.
 Prolonging the present biosphere is in humankind’s enlightened self interest since this
biosphere has enabled Homo sapiens to evolve and, at times, flourish.
 Since the present biosphere is the only one that humans have experienced, they tend to
forget that other biospheres not favorable to human survival have existed.
 Once a tipping point has been passed, changes are irreversible.
 If humankind wishes to maintain the present, favorable conditions, it should change
practices that alter the biosphere NOW!
THE SIGNS OF MARKEDLY INCREASED RISK TO
HUMANS AND THE BIOSPHERE ABOUND, BUT THEY
DIFFER CONSIDERABLY FROM ONE AREA TO
ANOTHER, AND PEOPLE TEND TO JUDGE GLOBAL
CHANGE BY LOCAL EVENTS (e.g., unseasonable
snowfall in an area means global warming is a hoax).
 “The earth continues to get warmer, yet it’s feeling a lot colder outside. Over the past few
weeks, subzero temperatures in Poland claimed 66 lives; snow arrived in Seattle well before
the winter solstice, . . . All of this cold was met with perfect comic timing by the release of
World Meteorological Organization report showing that 2010 will probably be among the
three warmest years on record, and 2001 through 2010 the warmest decade on record. . . .
the overall warming of the atmosphere is actually creating cold-weather extremes.”1
CLIMATE CHANGES ARE JEOPARDIZING FOOD
SUPPLIES IN A VARIETY OF WAYS INCLUDING
IRRIGATION WATER SHORTAGES, CHANGED RAINFALL
PATTERNS, DISEASE, ETC.
 The population is growing exponentially but the food supply is declining  for example, “a devastating
fungus, a wheat “rust,” is spreading out of Africa, a grave threat to the food plant that covers more of the
planet’s surface than any other.”2
 About 1,000 tons of water is needed to produce 1 ton of grain. Water shortages are a major problems,
especially as ground water aquifers are depleted.
 In third-world countries, food does not always reach consumers because of lack of transport,
refrigeration, or preservation.
 In the United States, food (corn) is turned into subsidized fuel (ethanol), which increases the price of corn
for poor people.
IF BANKS ARE “TOO BIG TO FAIL,”
WHY ISN’T THE BIOSPHERE
CONSIDERED “TOO BIG TO FAIL”?
 The human economy is a subset of the Biosphere, which provides the resources that fuel it.
 Banks can block financial transactions of ‘whistle blowers,”3 but failure of the Biosphere can drive Homo
sapiens to extinction. Which is the larger threat?
 The Biosphere has “whistle blowers”  Earth’s scientists who often pay dearly for their disclosure of
harm  who alert the public to actions that harm biospheric health.
 The financial system has many well funded lobbyists and “think tanks”  the Biosphere has few, poorly
funded ones.
MANY METAPHORS ILLUSTRATE WAYS THAT
THE BLAMELESS MESSENGER IS PUNISHED FOR
BRINGING BAD NEWS.
 Scientists use the objective, scientific method to gather evidence  evidence that offends
non-scientists is “bad” news, regardless of the quality.
 The scientific method, the peer-review process, and the opportunity to challenge published
evidence/analysis are superb quality control measures.
 “The fact is that the critics  who are few in number but aggressive in their attacks  are
deploying tactics that they have honed for more than 25 years . . . to stop action on climate
change, with special interests like Exxon Mobil footing the bill . . .”4
THE PRESENT SITUATION IS NOT HOPELESS AND
HUMANKIND NEEDS HOPE! THE FIRST STEP IS TO
RESTORE EARTH’S ENERGY BALANCE SO THAT IT
RADIATES AS MUCH TO SPACE AS IT ABSORBS FROM
THE SUN.5
 Carbon dioxide should be reduced by 35 to 40 ppm to increase Earth’s heat radiation to space.
 Eventually this reduction might return the pH of Earth’s oceans from mildly acidic to mildly alkaline.
 Anthropogenic carbon dioxide emissions are not likely to be reduced because of present political or
economic beliefs.
 The good news is that the United States is in a good position in terms of scientific status and productivity.
The bad news is that US teenagers rank 29th in science worldwide.6 Perhaps the cuts in US educational
funding are not a good idea since both citizens and students must understand the importance of Earth’s
energy balance.
THE BIOSPHERE IS IN PERIL, WHICH DOES NOT
BODE WELL FOR
HOMO SAPIENS.
 Life on Earth is probably not in danger, but the continued existence of humankind may be.
Many of the activities of humankind damage the Biosphere. If some organisms survive the
present great extinction, evolution will restore biodiversity.
 However, Homo sapiens is taking needless risks by assuming all biospheres will be as
nurturing as the present one.
 Humans must be willing to alter their lifestyles and their economy to preserve the present
Biosphere.
Acknowledgments. I am indebted to Darla Donald for transcribing the handwritten draft and for editorial assistance in preparation of the Power Point
presentation.
References
1Cohen,
J. 2010. Bundle up, it’s global warming. New York Times 25Dec http://www.nytimes.com/2010/12/26/opinion/26cohen.html.
C. J. 2010. The problem with wheat: resurgent disease, climate change threaten one of the world’s most important crops. Associated Press 26Dec
http://carbon-based-ghg.blogspot.com/2010/12/resurgent-disease-climate-change.html.
3Editorial. 2010. Banks and Wikileaks. New York Times 26Dec http://www.nytimes.com/2010/12/26/opinion/26sun3.html.
4Sachs, J. 2010. The phony attack on climate science. Economist’s View 19Feb http://economistsview.typepad.com/economistsview/2010/02/the-phonyattack-on-climate-science.html.
5Hansen, J. 2009. Storms of My Grandchildren. Bloomsbury, New York, p. 63.
6Paulson, A. 2007. New report ranks U.S. teens 29 th in science worldwide. Christian Science Monitor 5Dec http://www.csmonitor.com/2007/1205/p02s01usgn.html.
2Hanley,