Collapse: How Societies Choose to Fail or Succeed (4 page)

any particular human society, and may benefit one society while hurting
another society. (For example, we shall see that the Little Ice Age was bad for
the Greenland Norse but good for the Greenland Inuit.) In many historical
cases, a society that was depleting its environmental resources could absorb
the losses as long as the climate was benign, but was then driven over the
brink of collapse when the climate became drier, colder, hotter, wetter, or
more variable. Should one then say that the collapse was caused by human environmental impact, or by climate change? Neither of those simple alter
natives is correct. Instead, if the society hadn't already partly depleted its en
vironmental resources, it might have survived the resource depletion caused
by climate change. Conversely, it was able to survive its self-inflicted re
source depletion until climate change produced further resource depletion.
It was neither factor taken alone, but the combination of environmental im
pact and climate change, that proved fatal.

A third consideration is hostile neighbors. All but a few historical soci
eties have been geographically close enough to some other societies to have
had at least some contact with them. Relations with neighboring societies
may be intermittently or chronically hostile. A society may be able to hold
off its enemies as long as it is strong, only to succumb when it becomes
weakened for any reason, including environmental damage. The proximate
cause of the collapse will then be military conquest, but the ultimate
cause-
—the factor whose change led to the collapse—will have been the fac
tor that caused the weakening. Hence collapses for ecological or other rea
sons often masquerade as military defeats.

The most familiar debate about such possible masquerading involves
the fall of the Western Roman Empire. Rome became increasingly beset by
barbarian invasions, with the conventional date for the Empire's fall being
taken somewhat arbitrarily as
a.d.
476, the year in which the last emperor of the West was deposed. However, even before the rise of the Roman Empire,
there had been "barbarian" tribes who lived in northern Europe and Central
Asia beyond the borders of "civilized" Mediterranean Europe, and who pe
riodically attacked civilized Europe (as well as civilized China and India).
For over a thousand years, Rome successfully held off the barbarians, for in
stance slaughtering a large invading force of Cimbri and Teutones bent on conquering northern Italy at the Battle of Campi Raudii in 101
b.c.

Eventually, it was the barbarians rather than Romans who won the bat
tles: what was the fundamental reason for that shift in fortune? Was it be
cause of changes in the barbarians themselves, such that they became more
numerous or better organized, acquired better weapons or more horses, or

profited from climate change in the Central Asian steppes? In that case, we
would say that barbarians really could be identified as the fundamental
cause of Rome's fall. Or was it instead that the same old unchanged barbar
ians were always waiting on the Roman Empire's frontiers, and that they
couldn't prevail until Rome became weakened by some combination of eco
nomic, political, environmental, and other problems? In that case we would
blame Rome's fall on its own problems, with the barbarians just providing the coup de grace. This question continues to be debated. Essentially the same question has been debated for the fall of the Khmer Empire centered
on Angkor Wat in relation to invasions by Thai neighbors, for the decline in
Harappan Indus Valley civilization in relation to Aryan invasions, and for
the fall of Mycenean Greece and other Bronze Age Mediterranean societies
in relation to invasions by Sea Peoples.

The fourth set of factors is the converse of the third set: decreased sup
port by friendly neighbors, as opposed to increased attacks by hostile neigh
bors. All but a few historical societies have had friendly trade partners as
well as neighboring enemies. Often, the partner and the enemy are one and
the same neighbor, whose behavior shifts back and forth between friendly
and hostile. Most societies depend to some extent on friendly neighbors, ei
ther for imports of essential trade goods (like U.S. imports of oil, and Japanese imports of oil, wood, and seafood, today), or else for cultural ties that
lend cohesion to the society (such as Australia's cultural identity imported from Britain until recently). Hence the risk arises that, if your trade partner becomes weakened for any reason (including environmental damage) and
can no longer supply the essential import or the cultural tie, your own society may become weakened as a result. This is a familiar problem today because of the First World's dependence on oil from ecologically fragile and
politically troubled Third World countries that imposed an oil embargo in 1973. Similar problems arose in the past for the Greenland Norse, Pitcairn
Islanders, and other societies.

The last set of factors in my five-point framework involves the ubiqui
tous question of the society's responses to its problems, whether those
problems are environmental or not. Different societies respond differently
to similar problems. For instance, problems of deforestation arose for many
past societies, among which Highland New Guinea, Japan, Tikopia, and Tonga developed successful forest management and continued to prosper,
while Easter Island, Mangareva, and Norse Greenland failed to develop suc
cessful forest management and collapsed as a result. How can we under
stand such differing outcomes? A society's responses depend on its political,

economic, and social institutions and on its cultural values. Those institu
tions and values affect whether the society solves (or even tries to solve) its problems. In this book we shall consider this five-point framework for each
past society whose collapse or persistence is discussed.

I should add, of course, that just as climate change, hostile neighbors, and trade partners may or may not contribute to a particular society's collapse, environmental damage as well may or may not contribute. It would
be absurd to claim that environmental damage must be a major factor in all
collapses: the collapse of the Soviet Union is a modern counter-example,
and the destruction of Carthage by Rome in 146
b.c.
is an ancient one. It's
obviously true that military or economic factors alone may suffice. Hence a
full title for this book would be "Societal collapses involving an environ
mental component, and in some cases also contributions of climate change,
hostile neighbors, and trade partners, plus questions of societal responses."
That restriction still leaves us ample modern and ancient material to consider.

Issues of human environmental impacts today tend to be controversial, and
opinions about them tend to fall on a spectrum between two opposite camps.
One camp, usually referred to as "environmentalist" or "pro-environment,"
holds that our current environmental problems are serious and in urgent need of addressing, and that current rates of economic and population
growth cannot be sustained. The other camp holds that environmentalists' concerns are exaggerated and unwarranted, and that continued economic and population growth is both possible and desirable. The latter camp isn't
associated with an accepted short label, and so I shall refer to it simply as
"non-environmentalist." Its adherents come especially from the world of big
business and economics, but the equation "non-environmentalist" = "pro-
business" is imperfect; many businesspeople consider themselves environ
mentalists, and many people skeptical of environmentalists' claims are not
in the world of big business. In writing this book, where do I stand myself
with the respect to these two camps?

On the one hand, I have been a bird-watcher since I was seven years old.
I trained professionally as a biologist, and I have been doing research on
New Guinea rainforest birds for the past 40 years. I love birds, enjoy watch-
mg them, and enjoy being in rainforest. I also like other plants, animals, and habitats and value them for their own sakes. I've been active in many efforts
to preserve species and natural environments in New Guinea and elsewhere.

For the past dozen years I've been a director of the U.S. affiliate of World
Wildlife Fund, one of the largest international environmentalist organizations and the one with the most cosmopolitan interests. All of those things
have earned me criticism from non-environmentalists, who use phrases
such as "fearmonger," "Diamond preaches gloom and doom," "exaggerates
risks," and "favors endangered purple louseworts over the needs of people." But while I do love New Guinea birds, I love much more my sons, my wife,
my friends, New Guineans, and other people. I'm more interested in envi
ronmental issues because of what I see as their consequences for people
than because of their consequences for birds.

On the other hand, I have much experience, interest, and ongoing in
volvement with big businesses and other forces in our society that exploit environmental resources and are often viewed as anti-environmentalist. As
a teenager, I worked on large cattle ranches in Montana, to which, as an
adult and father, I now regularly take my wife and my sons for summer vacations. I had a job on a crew of Montana copper miners for one summer. I
love Montana and my rancher friends, I understand and admire and sym
pathize with their agribusinesses and their lifestyles, and I've dedicated this
book to them. In recent years I've also had much opportunity to observe
and become familiar with other large extractive companies in the mining,
logging, fishing, oil, and natural gas industries. For the last seven years I've
been monitoring environmental impacts in Papua New Guinea's largest
producing oil and natural gas field, where oil companies have engaged
World Wildlife Fund to provide independent assessments of the environment. I have often been a guest of extractive businesses on their properties, I've talked a lot with their directors and employees, and I've come to under
stand their own perspectives and problems.

While these relationships with big businesses have given me close-up
views of the devastating environmental damage that they often cause, I've also had close-up views of situations where big businesses found it in their interests to adopt environmental safeguards more draconian and effective
than I've encountered even in national parks. I'm interested in what moti
vates these differing environmental policies of different businesses. My
involvement with large oil companies in particular has brought me condemnation from some environmentalists, who use phrases such as "Dia
mond has sold out to big business," "He's in bed with big businesses," or "He
prostitutes himself to the oil companies."

In fact, I am not hired by big businesses, and I describe frankly what I see happening on their properties even though I am visiting as their guest.

On some properties I have seen oil companies and logging companies being
destructive, and I have said so; on other properties I have seen them being
careful, and that was what I said. My view is that, if environmentalists aren't
willing to engage with big businesses, which are among the most powerful forces in the modern world, it won't be possible to solve the world's envi
ronmental problems. Thus, I am writing this book from a middle-of-the-
road perspective, with experience of both environmental problems and of
business realities.

How can one study the collapses of societies "scientifically"? Science is often
misrepresented as "the body of knowledge acquired by performing repli
cated controlled experiments in the laboratory." Actually, science is something much broader: the acquisition of reliable knowledge about the world. In some fields, such as chemistry and molecular biology, replicated con
trolled experiments in the laboratory are feasible and provide by far the
most reliable means to acquire knowledge. My formal training was in two
such fields of laboratory biology, biochemistry for my undergraduate de
gree and physiology for my Ph.D. From 1955 to 2002 I conducted experi
mental laboratory research in physiology, at Harvard University and then at
the University of California in Los Angeles.

When I began studying birds in New Guinea rainforest in 1964, I was immediately confronted with the problem of acquiring reliable knowledge
without being able to resort to replicated controlled experiments, whether
in the laboratory or outdoors. It's usually neither feasible, legal, nor ethical
to gain knowledge about birds by experimentally exterminating or manipu
lating their populations at one site while maintaining their populations at another site as unmanipulated controls. I had to use different methods.
Similar methodological problems arise in many other areas of population
biology, as well as in astronomy, epidemiology, geology, and paleontology.

A frequent solution is to apply what is termed the "comparative method" or the "natural experiment"
—i.e., to compare natural situations
differing with respect to the variable of interest. For instance, when I as an
ornithologist am interested in effects of New Guinea's Cinnamon-browed
Melidectes Honeyeater on populations of other honeyeater species, I com
pare bird communities on mountains that are fairly similar except that some do and others don't happen to support populations of Cinnamon-
browed Melidectes Honeyeaters. Similarly, my books
The Third Chim
panzee: The Evolution and Future of the Human Animal
and
Why Is Sex Fun?