Collapse: How Societies Choose to Fail or Succeed (23 page)

How does Easter rate according to these nine variables predisposing to deforestation? It has the third highest latitude, among the lowest rainfalls, the lowest volcanic ash fallout, the lowest Asian dust fallout, no makatea, and the second greatest distance from neighboring islands. It is among the
lower and smaller of the 81 islands that Barry Rolett and I studied. All eight
of those variables make Easter susceptible to deforestation. Easter's volca
noes are of moderate age (probably 200,000 to 600,000 years); Easter's Poike
Peninsula, its oldest volcano, was the first part of Easter to become defor
ested and exhibits the worst soil erosion today. Combining the effects of all
those variables, Barry's and my statistical model predicted that Easter, Ni-
hoa, and Necker should be the worst deforested Pacific islands. That agrees
with what actually happened: Nihoa and Necker ended up with no human
left alive and with only one tree species standing (Nihoa's palm), while
Easter ended up with no tree species standing and with about 90% of its
former population gone.

In short, the reason for Easter's unusually severe degree of deforestation
isn't that those seemingly nice people really were unusually bad or improvident. Instead, they had the misfortune to be living in one of the most fragile
environments, at the highest risk for deforestation, of any Pacific people.
For Easter Island, more than for any other society discussed in this book, we
can specify in detail the factors underlying environmental fragility.

Easter's isolation makes it the clearest example of a society that destroyed
itself by overexploiting its own resources. If we return to our five-point
checklist of factors to be considered in connection with environmental col
lapses, two of those factors
—attacks by neighboring enemy societies, and
loss of support from neighboring friendly societies—played no role in
Easter's collapse, because there is no evidence that there were any enemies or friends in contact with Easter Island society after its founding. Even if it turns out that some canoes did arrive subsequently, such contacts could not have been on a large enough scale to constitute either dangerous attacks or important support. For a role of a third factor, climate change, we also have
no evidence at present, though it may emerge in the future. That leaves us
with just two main sets of factors behind Easter's collapse: human environ
mental impacts, especially deforestation and destruction of bird popula
tions; and the political, social, and religious factors behind the impacts,
such as the impossibility of emigration as an escape valve because of Easter's
isolation, a focus on statue construction for reasons already discussed, and

competition between clans and chiefs driving the erection of bigger statues
requiring more wood, rope, and food.

The Easter Islanders' isolation probably also explains why I have found
that their collapse, more than the collapse of any other pre-industrial soci
ety, haunts my readers and students. The parallels between Easter Island
and the whole modern world are chillingly obvious. Thanks to globaliza
tion, international trade, jet planes, and the Internet, all countries on Earth
today share resources and affect each other, just as did Easter's dozen clans. Polynesian Easter Island was as isolated in the Pacific Ocean as the Earth is today in space. When the Easter Islanders got into difficulties, there was no
where to which they could flee, nor to which they could turn for help; nor
shall we modern Earthlings have recourse elsewhere if our troubles in
crease. Those are the reasons why people see the collapse of Easter Island
society as a metaphor, a worst-case scenario, for what may lie ahead of us in
our own future.

Of course, the metaphor is imperfect. Our situation today differs in important respects from that of Easter Islanders in the 17th century. Some of
those differences increase the danger for us: for instance, if mere thousands
of Easter Islanders with just stone tools and their own muscle power suf
ficed to destroy their environment and thereby destroyed their society, how
can billions of people with metal tools and machine power now fail to do
worse? But there are also differences in our favor, differences to which we
shall return in the last chapter of this book.

CHAPTER
3

The Last People Alive:
Pitcairn
and Henderson
Islands

Pitcairn before the
Bounty
m
Three dissimilar islands
■ Trade ■
The movie's ending
m

M

any centuries ago, immigrants came to a fertile land blessed with
apparently inexhaustible natural resources. While the land lacked a
few raw materials useful for industry, those materials were readily
obtained by overseas trade with poorer lands that happened to have deposits of them. For a time, all the lands prospered, and their populations
multiplied.

But the population of the rich land eventually multiplied beyond the
numbers that even its abundant resources could support. As its forests were felled and its soils eroded, its agricultural productivity was no longer suffi
cient to generate export surpluses, build ships, or even to nourish its own
population. With that decline of trade, shortages of the imported raw materials developed. Civil war spread, as established political institutions were overthrown by a kaleidoscopically changing succession of local military
leaders. The starving populace of the rich land survived by turning to can
nibalism. Their former overseas trade partners met an even worse fate: de
prived of the imports on which they had depended, they in turn ravaged
their own environments until no one was left alive.

Does this grim scenario represent the future of the United States and
our trade partners? We don't know yet, but the scenario has already played
itself out on three tropical Pacific islands. One of them, Pitcairn Island, is
famous as the "uninhabited" island to which the mutineers from the H.M.S.
Bounty
fled in 1790. They chose Pitcairn because it was indeed uninhabited
at that time, remote, and hence offered a hiding place from the vengeful
British navy searching for them. But the mutineers did find temple plat
forms, petroglyphs, and stone tools giving mute evidence that Pitcairn had
formerly supported an ancient Polynesian population. East of Pitcairn, an
even more remote island named Henderson remains uninhabited to this

day. Even now, Pitcairn and Henderson are among the most inaccessible islands in the world, without any air or scheduled sea traffic, and visited only by the occasional yacht or cruise ship. Yet Henderson, too, bears abundant marks of a former Polynesian population. What happened to those original Pitcairn Islanders, and to their vanished cousins on Henderson?

The romance and mystery of the H.M.S.
Bounty
mutineers on Pitcairn, retold in many books and films, are matched by the mysterious earlier ends of these two populations. Basic information about them has at last emerged from recent excavations by Marshall Weisler, an archaeologist at the University of Otago in New Zealand, who spent eight months on those lonely outposts. The fates of the first Pitcairners and the Henderson Islanders prove to have been linked to a slowly unfolding environmental catastrophe hundreds of miles overseas on their more populous island trading partner, Man-gareva, whose population survived at the cost of a drastically lowered standard of living. Thus, just as Easter Island offered us our clearest example of a collapse due to human environmental impacts with a minimum of other complicating factors, Pitcairn and Henderson Islands furnish our clearest examples of collapses triggered by the breakdown of an environmentally damaged trade partner: a preview of risks already developing today in association with modern globalization. Environmental damage on Pitcairn and Henderson themselves also contributed to the collapses there, but there is no evidence for roles of climate change or of enemies.

Mangareva, Pitcairn, and Henderson are the sole habitable islands in the area known as Southeast Polynesia, which otherwise includes just a few low atolls supporting only temporary populations or visitors but no permanent populations. These three habitable islands were settled sometime around
a.d.
800, as part of the eastwards Polynesian expansion explained in the preceding chapter. Even Mangareva, the westernmost of the three islands and hence the one closest to previously settled parts of Polynesia, lies about a thousand miles beyond the nearest large high islands, such as the Societies (including Tahiti) to the west and the Marquesas to the northwest. The Societies and Marquesas in turn, which are the largest and most populous islands in East Polynesia, lie more than a thousand miles east of the nearest high islands of West Polynesia and may not have been colonized until perhaps nearly 2,000 years after West Polynesia's settlement. Thus, Mangareva and its neighbors were isolated outliers even within Polynesia's more remote eastern half. They were probably occupied from the Marquesas or

Societies during the same colonizing push that reached the even more re
mote Hawaiian Islands and Easter, and that completed the settlement of
Polynesia (maps, pp. 84-85 and this page).

Of those three habitable islands of Southeast Polynesia, the one capable
of supporting by far the largest human population, and most abundantly
endowed with natural resources important to humans, was Mangareva. It
consists of a large lagoon 15 miles in diameter, sheltered by an outer reef,
and containing two dozen extinct volcanic islands and a few coral atolls
with a total land area of 10 square miles. The lagoon, its reefs, and the ocean
outside the lagoon teem with fish and shellfish. Especially valuable among
the species of shellfish is the black-lipped pearl oyster, a very large oyster of
which the lagoon offered virtually inexhaustible quantities to Polynesian settlers, and which is the species used today to raise the famous black cul
tured pearls. In addition to the oyster itself being edible, its thick shell, up to
eight inches long, was an ideal raw material that Polynesians carved into
fishhooks, vegetable peelers and graters, and ornaments.

The higher islands of Mangareva's lagoon received enough rain to have
springs and intermittent streams, and were originally forested. In the nar
row band of flat land around the coasts, the Polynesian colonists built their

settlements. On the slopes behind the villages they grew crops such as sweet potato and yams; terraced slopes and flats below the springs were planted in
taro, irrigated by spring water; and higher elevations were planted in tree crops such as breadfruit and bananas. In this way, farming and fishing and
gathering of shellfish would have been able to support a human population of several thousand on Mangareva, more than 10 times the likely combined
populations of Pitcairn and Henderson in ancient Polynesian times.

From a Polynesian perspective, Mangareva's most significant drawback
was its lack of high-quality stone for making adzes and other stone tools.
(That's as if the United States contained all important natural resources ex
cept high-grade iron deposits.) The coral atolls in Mangareva lagoon had
no good raw stone at all, and even the volcanic islands offered only rela
tively coarse-grained basalt. That was adequate for building houses and garden walls, using as oven stones, and fashioning into canoe anchors and food pounders and other crude tools, but coarse-grained basalt yielded only infe
rior adzes.

Fortunately, that deficiency was spectacularly remedied on Pitcairn, the much smaller (2V2 square miles) and steeper extinct volcanic island lying 300 miles southeast of Mangareva. Imagine the excitement when the first canoeload of Mangarevans discovered Pitcairn after several days' travel on
open ocean, landed at its only feasible beach, scrambled up the steep slopes, and came upon Down Rope Quarry, Southeast Polynesia's sole useable lode
of volcanic glass, whose flakes could serve as sharp tools for fine cutting
tasks
—the Polynesian equivalent of scissors and scalpels. Their excitement
would have turned to ecstasy when, barely a mile farther west along the
coast, they discovered the Tautama lode of fine-grained basalt, which be
came Southeast Polynesia's biggest quarry for making adzes.

In other respects, Pitcairn offered much more limited opportunities than did Mangareva. It did have intermittent streams, and its forests in
cluded trees large enough to fashion into hulls of outrigger canoes. But Pit-
cairn's steepness and small total area meant that the area of level plateau
suitable for agriculture was very small. An equally serious drawback is that
Pitcairn's coastline lacks a reef, and the surrounding sea bottom falls off
steeply, with the result that fishing and the search for shellfish are much less
rewarding than on Mangareva. In particular, Pitcairn has no beds of those black-lipped pearl oysters so useful for eating and tool-making. Hence the
total population of Pitcairn in Polynesian times was probably not much
greater than a hundred people. The descendants of the
Bounty
mutineers
and their Polynesian companions living on Pitcairn today number only 52.