Five Tools for Going Forward

Paul Seabright

Twenty years after The Limits to Growth comes the sequel. It’s a hard act to follow: the original sold nine million copies and made its authors and backers, the so-called Club of Rome, famous with its prophecy that the comfortable optimism of the Sixties was threatened by a combination of population growth, resource exhaustion and the effluents produced by affluence. The authors used a large computer model to project economic and demographic trends, and predicted a collapse of living standards by the middle of the 21st century unless dramatic changes were made. A decade after the Cuba missile crisis, a world that was learning to live with the superpower confrontation reacted in alarm to the warning that a population explosion would be no less deadly than that of the ICBMs, and much harder to control. Some pessimists even derived a certain lugubrious pleasure from thinking the baby boom more inevitable and more damaging than the atomic kind. Demographic warfare differs from the traditional sort in that going nuclear usually signals de-escalation. But the authors warned that slowing the birth rate (did they choose the title Club of Rome deliberately?) would be nothing like enough to avoid calamity. At any foreseeable stable population level, even existing consumption trends would exhaust the world’s resources and pollute its environment beyond repair.

Some of the messages of The Limits to Growth would hardly be thought controversial today. Environmental concern is now entirely respectable: indeed it forms an increasing part of the activities of such institutions as the World Bank and attracts any amount of celebrity endorsement. Many of its terms of art have entered everyday usage: the distinction between renewable resources, like forests, and non-renewable ones, like oil, is familiar to most non-specialists. That not all environmental problems can be left to the good sense of individual countries to sort out has also become evident, particularly where global warming and the ozone layer are concerned; and the Montreal Protocol on chlorofluorocarbon emissions has been an encouraging sign of the world community’s ability to respond collectively if a problem is sufficiently pressing (the story is well documented here). In some ways, too, the authors’ methodology has become more acceptable. Large-scale computer modelling is now commonplace, and the familiarity of chaos theory has meant that the sensitivity of a model’s predictions to initial conditions is no longer considered to its discredit. This is just as well, since the graph in which the authors superimpose all their projections of national income under different assumptions looks like a fan made out of spaghetti. On the other hand, as the authors implicitly acknowledge, many of the views they held twenty years ago seem simplistic today (some did so even then). In particular, the ease with which resource scarcity can lead to substitution has been strikingly apparent, both in the conservation measures initiated after the 1973 oil crisis and in the development of synthetic substitutes for many natural products. The exhaustion of a natural resource cannot, after all, leave us worse-off than we were before its original discovery. Wilfred Beckerman once pointed out that the world had survived remarkably well in the absence of Beckermonium, a mineral named after an ancestor of his who failed to discover it in the 19th century.

The central theme common to this and the earlier book is the nature of the limits to the Earth’s capacity to sustain life and economic activity. That there are such limits is an obvious, indeed banal point. But the authors claim that these limits have two important properties: first, if we run up against them sufficiently hard the consequence will be a complete collapse of our capacity to survive, and second, that our decentralised warning mechanisms (for example, the tendency of prices to rise as a resource becomes scarce) will not enable us to avoid such collapse – rather as a supertanker will be doomed if it relies on a human lookout rather than on radar to warn of the approach of the harbour wall.

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[*] This is not strictly correct. It is theoretically possible for the rate at which output is produced from given resources to increase fast enough to offset for ever the declining levels of those resources. But to do so it would have to increase at an accelerating rate, and this model – like most sensible ones – assumes that the more efficiently a given resource is utilised, the harder it is to make further efficiency improvements.