This book stands in an ancient intellectual tradition. Its theme dates back to the year 1798, in which the English economist Thomas Malthus published his famous theory of demography. Human population, Malthus reasoned, grows exponentially, as each extra couple multiplies itself in turn; whereas food production can increase only arithmetically, and beyond a point not at all. Return to equilibrium is possible only through starvation or disease, provoked either by natural catastrophe or by wars over the scarce remaining resources.
The resources of the earth have proved to be more elastic than Malthus foresaw. The mechanisms by which they may be exhausted are infinitely more complicated than he realised. And, apart from the phenomenon of soil exhaustion, which had been familiar to mankind since ancient times, he did not foresee the actual destruction of the productive capacity of the earth in the process of trying to extract more from it. Nor did he anticipate the technology by which mankind would one day acquire the means of controlling its own fertility. But for all this, Malthusian theory remains broadly speaking the foundation of most ecological concerns about mankind’s future.
Jared Diamond’s important book is a sober account by a reputable American scientist of historical communities in which the Malthusian dynamic has gone to its ultimate conclusion: collapse. Easter Island is probably the paradigm case, and certainly the best known. Diamond starts with it. After the first arrival of men on the island, they lived on their capital, consuming the produce of what was once a thickly wooded paradise, rich in animal and plant life. Prosperity multiplied their numbers, and in the course of about 500 years the island became a desert, the forest vanished. Without trees, the soil eroded and supported no crops; bird and mammal life became extinct; men could no longer make canoes from which to fish. In due course, men too became extinct on Easter Island. From this awful beginning, Diamond moves on to find the same symptoms in other Pacific islands, and then in communities closer to Western experience: Central America, Iceland and Greenland, Rwanda, the Dominican Republic, finally Australia and the United States. The prime mechanisms of the coming crisis, in his view, are population growth and deforestation, followed by global warming and other symptoms of atmospheric pollution.
We have heard much of this before, although rarely with as much detailed information or dispassionate analysis. It is history as moral lesson, the kind of history which was once used to warn generations of schoolchildren of the perils of popery, tyranny, masturbation and surfeits of lampreys, but is now deployed mainly by prophets and ecologists. Yet historical analogies are rarely exact. There are always variables whose significance is more or less difficult to assess.
Perhaps the most important variable in this case is the one implicit in Diamond’s subtitle, ‘How Societies Choose to Fail or Survive’. The Easter Islanders did not ‘choose to fail’, whereas modern societies may plausibly be said to do so. The difference is that the islanders lacked the basic knowledge to make a choice, whereas we have a reasonably good understanding of what is happening to us and why. We can therefore, at least in theory, change our habits to avoid worse misfortune. Diamond of course understands this perfectly. Otherwise there would be no point in his warning.
He professes himself to be cautiously optimistic about the outcome. Mankind will be saved. Most people will agree with him about this, although not necessarily for the same reasons. People will not change their ways for moral reasons, at least not in sufficient numbers to make the difference. Although some individuals may plan for the long-term improvement of mankind, men en masse respond to the unspoken calculus of advantage and disadvantage. Most activities which damage the environment are immediately enjoyable or profitable or both. In some places, they are the only alternative to immediate starvation. But the ecological benefits produced by abandoning them seem remote, and they depend on everyone else, worldwide, making the same choice.
Diamond’s touching faith in democracy as the ultimate answer will not convince every one. Democratic governments respond to average opinion, not to enlightened opinion. And they respond to their electorates, not to the world. As President Bush has unintentionally reminded us, there is an immediate cost to ecological virtue which electorates are not usually willing to pay, especially if they think that much of the benefit will go to free riders living elsewhere. These things are easier for tyrants. It was President Balaguer of the Dominican Republic who devised the most effective remedy to date for third- world logging. He sent in troops to machine-gun the loggers from helicopters.
All this suggests that the situation will have to get a great deal worse before it gets better, and will no doubt be correspondingly more expensive and difficult to deal with when the time comes. But it will happen, because one day the catastrophe will be sufficiently imminent for the calculus of advantage and disadvantage to point another way. The end may not be far off, but neither is it nigh. People will change their ways in response to an imminent and perceptible impact on their own way of life. They will not do so in response to mere exhortation. It does not of course follow that exhortation is useless. Works like Jared Diamond’s have the great virtue of setting out the choices, so that we can make them when eventually we have to.