IMAGINE AN EARTH SUMMIT AT WHICH THE DELEGATES were magically insulated from nationalist, religious and cultural pressures and then told to pick one issue that had the most impact on the quality of the environment and the cause of sustainable development. There is little doubt what this dream conference would focus on: population. By itself, controlled population growth will not solve the world's problems, but if human numbers and consumption continue to rise unabated, there is little hope for the other creatures with whom we share the earth and a high probability of catastrophe for humanity itself. After years of preparation, however, the negotiators preparing the main documents for Rio have relegated the issue to a few delicately worded phrases. In the draft of the Rio Declaration, the sole mention of population is a deliberately ambiguous reference to "appropriate demographic policies."
The problem is that the negotiators cannot operate in a world divorced from dogmas. In the case of discussions about birth control, the pressures came from the Vatican and fundamentalist Muslims. Ironically, according to summit officials, feminists led by former U.S. Congresswoman Bella Abzug may have unintentionally aided the forces aligned against family planning by pushing aggressively for a more liberal women's reproductive-rights agenda than the conservative cultures in the developing world could accept.
Unfortunately, the summit's capitulation on the population question will probably nullify whatever progress the conference makes on other issues. The United Nations Population Fund has just released new forecasts for population growth, which have been raised sharply. In 1980 the agency projected that the world's population, now at 5.4 billion, would stabilize at 10 billion people roughly 100 years from now, but the new estimates show it surpassing 11.6 billion by the year 2150.
And that prediction may be optimistic, based on the assumption that developing nations can reduce their birthrate from 3.8 children per mother to 3.3 by the year 2000. If that reduced birthrate is not reached until 2010, the population will hit 12.5 billion by the middle of the next century -- unless mass starvation, disease or war curbs the numbers. Almost all these people would live in developing countries, and it is difficult to imagine how any agreement coming out of Rio could offset the negative impact of this tide of humanity.
"We already have a full-occupancy planet," says Noel Brown, North American director of the U.N. Environment Program. Today 80% of deforestation results from population growth. If the numbers keep rising until 2050, the U.N. estimates, an additional 5.9 million sq km (2.3 million sq. mi.) of land will have to be turned over to farming, roads and urban uses. This is almost equivalent to the total size of protected natural areas on earth today. Most good agricultural land is already under plow, and each year desertification, improper irrigation and overuse take millions of acres out of production. Farms may increase in productivity, but it will be much harder to match the gains of the past, and whether agricultural output can keep pace with population is an open question.