Technological Optimists and Pessimists: The Great Ideological Divide
For some time the world's environmental movement has tried to mediate the competing claims of two rival schools regarding planetary limitations. On the one hand, there are neo-Malthusians, acutely aware of the constraints that a finite planet places on human development. This view sees Earth's resources as limited; in the face of geometric growth in population and consumption, famine and misery are ineluctable. “Sustainable growth” by definition is an oxymoron.1 At the heart of any environmentally sound strategy for the future is self-restraint and sacrifice.
This view is challenged by a diverse group of advocates on the other extreme who are variously referred to as “cornucopians” or Prometheans. (Presumably, by bestowing fire on humanity, Promotheus provided humans with the means and inventiveness to become like gods.2) These technological optimists are confident that human ingenuity will be able to overcome any pollution problems3 or projected shortages and produce the necessary supply of resources or substitutes to expand global prosperity.4 The two views have clashed for more than 40 years, since the pessimistic projections of the Club of Rome5 and the highly publicized bet between economist Julian Simon and ecologist Paul Ehrlich over the anticipated rise in the prices of five metals due to scarcity.
Water scarcity constitutes a defining issue in this ongoing debate. On the one hand, the neo-Malthusean pessimists foresee increased shortages leading to massive deprivation, starvation, and the proliferation of water conflicts due to competition over hydrological assets.6 Promethian, hydrological optimists, on the other, are sanguine about future water supply7,8: Water is more renewable than ever before, and modern societies today can produce as much of it as they need or want. The opposing positions on the merits of seawater desalination offer a characteristic manifestation of this ideological divide. With 15,000 desalination plants presently in operation, providing some 300 million people with water today, the issue is particularly germane. Whether the world's mounting interest in “desal” constitutes a panacea for perennial scarcity or merely a greenhouse-gas-intensive bandage for wealthy nations is a debate that hitherto has largely been conducted on a hypothetical, theoretical plane. However, recent experience in several countries offers an empirical basis for assessing the sustainability of desalination, which along with wastewater reuse promises to eliminate the projected water shortages of the future. In particular, Israel, Australia, and Spain offer different policy approaches to this aspect of water management.
Alon Tal is a faculty member at the Institutes for Dryland Environment Research at Ben Gurion University.