The United Nations Earth Summit, held in Rio de Janeiro in June of 1992, illuminated some major differences among the nations of the world, differences that are summarized in the terms North and South. The latter term refers to nations of the Southern Hemisphere—nations that have significantly different environmental concerns from those of their northern neighbors. These concerns arise primarily from rapid population growth; low levels of technological and industrial development; and generally difficult living conditions.

The distinction between North and South did not originate with the Rio conference. It was popularized by a report delivered in 1980 to the Secretary-General of the United Nations by a commission headed by Willy Brandt (1913-1992), the former Chancellor of West Germany. The report, which was entitled To Ensure Survival—Common Interests of the Industrial and Developing Countries, is sometimes referred to as the Brandt Report. It recommended a marked rise in...