Wright writes a colourful history of our species and sets about asking of humanity three questions posed by the reclusive artist Gauguin: "Where do we come from? What are we? Where are we going?" (p. 2). Detailing amongst other things how four historical civilizations in particular — those of Easter Island, Sumer, the Maya and Rome — self-destructed from a combination of lack of foresight and poor choices that lead to overpopulation and irreparable environmental damage. From his reading of the "flight recorders in the wreckage of crashed civilizations" (p. 129) such as these there follows the persistent concern that "each time history repeats itself, the price goes up", and the lessons our now global civilization should therefore have learnt from them in order to become sustainable today with reference also to global warming and climate change.
Wright begins his journey with pre-agricultural or hunter-gatherer man in the Stone age and the worldwide slaughter of megafauna whenever and wherever Homo sapiens migrated to new lands. He includes that other Ice Age hunter, Neanderthal man, and argues that our closest evolutionary relative and competitor may well have been the first victim of human genocide: "or, worse, not the first — merely the first of which evidence survives" (p. 25). And further: "it may follow from this that we are descended from a million years of ruthless victories, genetically predisposed by the sins of our fathers to do likewise again and again".
In analysing his four particular cases, Wright notes that Easter Island and Sumer failed due to depletion of natural resources: "their ecologies were unable to regenerate". Whereas the Maya and Rome failed in their heartlands, "where ecological demand was highest," but left remnant populations that survived. He asks: "Why, if civilizations so often destroy themselves, has the overall experiment of civilization done so well?" For the answer, he says, we must look to natural regeneration and human migration (p. 102).
Wright argues that while most ancient civilizations depleted their ecologies and failed, few thrived. Large expanses of our (now shrinking) planet remained unsettled and available for migration. And a handful of civilizations — as evidenced by Egypt and China (pp. 103–4) — experienced greater longevity for atypical reasons:
* an abundance of resources, particularly topsoil, with alluvial deposits from annual Nile River flooding and wind-blown glacial loess that was exceedingly deep, respectively
* farming methods that worked with, rather than against, natural cycles
* settlement patterns that did not exceed, or permanently damage, the carrying capacity of the local environment
Wright borrows from Joseph Tainter in identifying three models of societal collapse — the "Runaway Train", the "Dinosaur", and the "House of Cards" (p. 107, 128) — emphasizing that they usually operate in combination and going further in suggesting that civilization itself "is an experiment, a very recent way of life in the human career, and it has a habit of walking into what I am calling progress traps" (p. 108). "Material progress creates problems that are — or seem to be — soluble only by further progress ... the devil here is in the scale: a good bang can be useful; a better bang can end the world" (p. 7). In addition to describing in detail these sorts of technological "progress traps" throughout the book — including even the invention of agriculture itself — Wright labels such cultural beliefs and interests that act against sustainability — and hence civilizational survivability as a whole — the very worst kind of "ideological pathology":
“ We still have differing cultures and political systems, but at the economic level there is now only one big civilization, feeding on the whole planet’s natural capital. We’re logging everywhere, building everywhere, and no corner of the biosphere escapes our haemorrhage of waste. The twentyfold growth in world trade since the 1970s has meant that hardly anywhere is self-sufficient. Every Eldorado has been looted, every Shangri-La equipped with a Holiday Inn. Joseph Tainter notes this interdependence, warning that "collapse, if and when it comes again, will this time be global. ... World civilization will disintegrate as a whole." ”
Changes brought on by the exponential growth of the human population — over six billion by 2006 and adding over 70 million additional people every year — the worldwide scale of resource consumption — an area of farmland the size of Scotland lost to erosion every year — have altered the picture. Ecological markers now indicate that human civilization has surpassed (since the 1980s) nature's capacity for regeneration. Humans in 2006 used more than 125% of nature's yearly output annually: "If civilization is to survive, it must live on the interest, not the capital of nature" (p. 129).
Wright concludes that "our present behaviour is typical of failed societies at the zenith of their greed and arrogance" (p. 129). "It is a suicide machine" and "Things are moving so fast that inaction itself is one of the biggest mistakes. The 10,000-year experiment of the settled life will stand or fall by what we do, and don’t do, now". We must therefore "transition from short-term to long-term thinking", "from recklessness and excess to moderation and the precautionary principle" (p. 131).
Just as for the Easter Islanders before us the collapse of human civilization appears imminent if we do not act immediately to prevent it and his final prognosis for our future is a far less positive one than Jared Diamond's Collapse: How Societies Choose to Fail or Succeed.