This Easter Island Earth

An ongoing tour of literature related to astrobiology, hosted by Dr. David Grinspoon, Curator of Astrobiology at the Denver Museum of Nature & Science.


Dr. David Grinspoon, Curator of Astrobiology at the Denver Museum of Nature & Science. Click image for larger view.

Greetings people of Earth. In this space we will present reviews of current and classic books related to questions about life in the universe, written by colleagues and friends from the field of Astrobiology, or the many related fields in the Earth, space and life sciences.

We will cast a wide net, including scholarly and popular books, fiction and nonfiction, books focused directly on astrobiology, as well as those that are more tangentially related to the field, yet help to illuminate the subject in interesting ways. Who knows, maybe we’ll even include an occasional movie, CD or interstellar webcast.

Here, Linda Sauter reviews Jared Diamond’s Collapse, a book that is not obviously about astrobiology, but one that upon closer examination bears upon some important questions about the likely development of life and civilizations in the universe. Sauter is a graduate student in the University of Washington’s Astrobiology program. Her research is on life detection, more specifically on developing fluorescent biosensors in microfluidic devices for physiological fingerprinting of individual cells. She is particularly interested in applications such as project Neptune, a regional-scale ocean observatory in the northeast Pacific Ocean, and the next generation of missions to Jupiter’s moon Europa.

This Easter Island Earth
By Linda Sauter

In 1961, radio astronomer Frank Drake devised an equation to express how many observable civilizations should be in our galaxy. The last variable in the Drake Equation, “L”, the lifetime of a communicating civilization, is difficult to pin down. On Earth, we have been communicating with radio waves for less than 100 years. Will our civilization continue at this level of technological sophistication for another 100 years? We certainly hope so. Another 10,000 years? This seems less certain. Another billion years? Impossible to say.

Star field
Estimates suggest that up to a quarter of all stars have planets.
Credit: NASA/ STScI/ ESA

The differences in these estimates profoundly affect the Drake Equation. Given the vast distances of space and the long times required to communicate using electromagnetic radiation, the lifetime of communicating civilizations will make the difference between taking part in a Galactic conversation and tossing occasional notes in bottles into the vast interstellar sea.

The biggest problem in estimating this variable in the Drake Equation, some say, is that we have only one example to go by. Our civilization on Earth in the 20th and 21st centuries is a new experiment built on a tumultuous history, and its future stability is not yet assured. Technologies, once established, may become essential to a civilization or may be instrumental in its destruction. Is there any way to predict whether our current civilization will continue to listen to the stars for many millennia to come? Can we assume that our story is sufficiently representative to lend insight into the lifetime of other galactic communicators? Are there any other data we can analyze to get at the underlying factors that determine the lifetime of a civilization?

Perhaps we can learn from the past. In Jared Diamond’s new book, Collapse: How Societies Choose to Fail or Succeed, he discusses the techniques used by archaeologists to follow the rise and fall of civilizations. Collapse provides data from isolated civilizations of the past, and compares these case studies to unearth causes of their success or failure.

Fans of Jared Diamond will find this follow-up to his Pulitzer Prize-winning Guns, Germs, and Steel fascinating. Even if you found the earlier work tedious, take heart, for Collapse is both more varied and more succinct in its arguments. Writing for the general public, Diamond develops his arguments clearly, though the conclusions might seem a bit one-sided.

Jared Diamond’s book, “Collapse: How Societies Choose to Fail or Succeed.”

The book is structured into four parts. In part two, “Past Societies,” Diamond spins intriguing tales about the South Pacific (including Easter Island), the ancient Anasazi and Maya in Mesoamerica, and spends a great deal of time following the travels and lives of the Vikings in the North Atlantic. Along the way, readers learn about the methods of tree-ring dating, the study of pack-rat middens, and what pollen gathered from bogs can tell us about extinct plant populations. Collapse is written with an enthusiasm for discovery that the reader can’t help but share.

Readers initially will be struck by the apparent foolishness of a society like that on Easter Island, a civilization that relied on trees for every aspect of its survival, and yet cut down every last one, spiraling into a collapse rife with warfare and cannibalism. The question often asked is, “What did the Easter Islander who cut down the last tree say while he was doing it?” It’s a question that begs for a bad punch line, if it wasn’t so tragic. Modern peoples often dismiss ancient societies as naïve and ignorant. But the Polynesians were a cunning people who colonized hundreds of islands across the vast distances of the Pacific in a short span of time. They were very aware of their environment and its resources. It was an incredible achievement to build a civilization of up to 15,000 people on Easter Island – a 100-square kilometer hunk of rock that is 2,000 kilometers away from its nearest neighbors – and maintain it for almost a thousand years. If NASA could build a civilization on the Moon or Mars that was one-tenth as successful, it would be considered one of the great achievements in human history.

So why do civilizations collapse? By comparing the different trajectories of isolated societies in the past (the hundreds of Polynesian settlements in the Pacific make up a robust data set), Diamond has discerned some common factors that correlate with long-term survival or collapse. In particular, he compares the severity of deforestation on Pacific islands, and determines that islands that are dry, cold, small, old, remote, low, and/or far from sources of ash and dust are more fragile and susceptible to environmental damage than other islands. Easter Island, as it turns out, rates as one of the most fragile environments by these factors. Using comparative methods such as these, Diamond expands his studies to include ancient societies across Mesoamerica, New Guinea, and the North Atlantic, and modern civilizations such as China, Australia, and Haiti.

Linda Sauter, of the University of Washington’s Astrobiology program. Click image for larger view.

From the perspective of Astrobiology, it is interesting to look at the causes for collapse in terms of the whole planet over the longest possible timescale. For ultimately, the Earth is Easter Island. Diamond breaks down the collapse factors into several categories. The first several factors include deforestation, habitat destruction, soil erosion and fertility loss, and freshwater loss and contamination. Trees seem to be an intrinsically renewable resource. But forest destruction, in conjunction with soil erosion and water loss, makes the loss of forest habitat an accelerating and potentially irreversible problem on this planet. Trees cannot grow back in places where the soil is lost, and soil regenerates at a much slower pace than that at which it is lost. Therefore, deforestation can be considered a global collapse factor for our modern civilization. The size and timescale of this factor is less certain, but could become critical within a century or two at current rates.

A second group of factors includes overhunting, overfishing, and the introduction of nonnative species. Hunting and fishing can in the short term be replaced by animal husbandry, agriculture and aquaculture, but these food sources have their own consequences in terms of soil fertility, animal waste accumulation, and water pollution. We are in the throes of a mass extinction of plant and animal species on this planet, caused at least in part by human practices of habitat destruction and climate change. There is an accelerating need for protein to feed a growing human population, and current protein sources are inefficient and unsustainable. How much longer will it be practical to grow animals as food? Can technology save us? Will we collapse in warfare and cannibalism, as the Easter Islanders did? When will these problems become global and acute? It is clear that we are in a human-dominated age of the biosphere of Earth. Whether and how the Earth will correct herself from this imbalance is unclear, but the timeline for these problems to come to a head could be as soon as decades or centuries.

The next set of factors includes human population growth and increased per-capita impact of people. It is the combination of these factors that is most important. Can the planet accommodate 6 billion people? So far, it seems, yes. But it cannot sustain 6 billion people living a modern American lifestyle. And the Third World will not be held down peacefully, or ethically, from aspiring to a First World lifestyle. Can the planet sustain 12 billion people? It is hard to imagine, but at the current rate of population doubling, we will learn the answer to this question in our lifetime.

The Moon, Venus, and Mars seen behind Ahu Tahai, a famous Easter Island statue. The bright star Aldebaran is also visible. Click image for larger view.
Credit: Magnus Galfalk, Stockholm Observatory

An Astrobiologist might answer that in terms of the Drake Equation, we only need a social elite that can operate radio telescopes, and this can be maintained in spite of these factors for a long time. Look at the “Dark Ages” in Europe. The intelligentsia in their ivory towers were scribbling in their notebooks and looking at the stars while the peasants starved. But Diamond answers, look at the Maya. The kings in their palaces might have been the last to starve, but starve they did all the same.

Diamond’s last collapse factors are new for modern civilizations: human-caused climate change, buildup of toxic chemicals in the environment, energy shortages, and full human utilization of the Earth’s photosynthetic capacity. He warns: “Much more likely than a doomsday scenario involving human extinction or an apocalyptic collapse of industrial civilization would be “just” a future of significantly lower living standards, chronically higher risks, and the undermining of what we now consider some of our key values. Such a collapse could assume various forms, such as the worldwide spread of diseases or else of wars, triggered ultimately by scarcity of environmental resources. If this reasoning is correct, then our efforts today will determine the state of the world in which the current generation of children and young adults lives out their middle and late years.”

Perhaps Collapse is too alarmist, but it does give reasons for hope, and it is not ultimately pessimistic. It is passionate in its plea for us to see the signs of collapse in our current global civilization, and be forewarned. It is a daring work. If the reader comes to it for the stories of the Maya and the Vikings, it is a thrilling tale. If one reads it for its look at modern societies such as Australia and Rwanda and Haiti, it provides an interesting perspective. Read it as an Astrobiologist, and think about all of those other civilizations in time and space, winking on, listening, and perhaps winking off again. Have hope, and work ever harder to keep the phone on here on this Earth, our small, remote island in space.

Related Web Pages

SETI and the Cosmic Quarantine Principle
The Great Debate: Is Complex Life Common in the Universe?
Cause for Optimism: Part III : The Drake Equation Revisited
Drake Matrix
Cosmic Imperative for Life: Ann Druyan Interview
Search for Life in the Universe: Neil deGrasse Tyson Interview
Mars in Pop Culture: Literature