Nearly four decades ago, British economist E.F. Schumacher stated the essence of environmental protection in three words: Small is beautiful. As Schumacher argued in his famous book by that title, man-made disturbances of the natural world-farms, for example, and power plants-should have the smallest possible footprints.

But how can that ideal be realized in a world that must produce more and more food and energy for its growing population? The answer, in just one word, is density.

Over the course of the last century, human beings have found ways to concentrate crops and energy production within smaller and smaller areas, conserving land while meeting the ever-growing global demand for calories and watts. But this approach runs counter to the entrenched beliefs of many environmental activists and politicians, whose "organic" and "renewable" policies, as nature-friendly as they sound, squander land and other resources.

Food cultivation exemplifies the virtues of density. During the second half of the 20th century, hybrid seeds and synthetic fertilizers, along with better methods of planting and harvesting, produced stunning increases in agricultural productivity. Between the mid-1960s and mid-2000s, global production of all cereal crops doubled, according to U.N. data, even though the amount of cultivated acreage remained about the same.

Indur Goklany, a policy analyst for the U.S. Department of the Interior, estimates that if agriculture had remained at its early 1960s level of productivity, feeding the world's population in 1998 would have required nearly eight billion acres of farmland, instead of the 3.7 billion acres that were actually under cultivation. Where in the world-literally-would we have found an extra 4.3 billion acres, an area slightly smaller than South America?

Meanwhile, a recent analysis of U.S. Department of Agriculture data, by plant pathologist Steve Savage, found that land devoted to organic farming produces about 29% less corn and 38% less winter wheat than the same acreage conventionally farmed. Since world population is growing and food prices are already at near-record highs, mandates for organic farming could be disastrous. For example, low-density agriculture could increase deforestation as farmers desperately seek more farmland-a result that should disturb environmentalists.

David Fuller's view Not everyone will like the conclusions in this intelligent article, because they clash with our romanticised fantasies of what life on our planet should be like... that is... if we could downsize to the global population of the 18th century while retaining our more comfortable technology.

However this does not seem very fair on the people we would have to lose. A more enlightened alternative might be to pay more attention to EF Schumacher and keep on developing our wonderful technologies and use them to improve the planet.