IN an unprecedented joint statement, the presidents of the two most prestigious scientific bodies in the United States and Great Britain recently outlined the relationship between world population growth and the health of the global environment. In atypically dramatic fashion, the National Academy of Sciences (NAS) and the Royal Society of London warned that "if current predictions of population growth prove accurate and patterns of human activity on the planet remain unchanged, science and technology ma y not be able to prevent either irreversible degradation of the environment or continued poverty for much of the world."
Noting that world population is growing at a rate of almost 100 million people a year and could double by the mid-21st century, the scientists argued that the upcoming United Nations Conference on Environment and Development (UNCED) - the Earth Summit - should "consider human activities and population growth, in both developing and developed worlds, as crucial components affecting the sustainability of human society."
This declaration sent a powerful message to world leaders: Our environmental survival depends on stopping the population explosion that threatens to overwhelm the planet's ability to support humanity.
While population has been considered in the context of environmental problems such as soil degradation and deforestation, policymakers have neglected its relevance to global warming. The scientists' statement links population and global warming: more people, more pollution.
Ironically, the global warming treaty - expected to serve as the centerpiece of the Earth Summit - does not include a single reference to population in more than 60 pages of negotiating text. Only cursory attention has been paid to it in other preparatory meetings for UNCED, and no major population initiatives will be unveiled at the Earth Summit.
The critical link between population and global warming has only recently become an important focus for scientists and population experts. The results of these studies are best explained by former US Sen. Daniel Evans, chair of the NAS's global warming panel, who concluded in 1991 that "population is the single biggest driver of atmospheric pollution." According to a recent analysis by the United Nations Population Fund, between 1950 and 1985 (when population nearly doubled from 2.5 billion to just under
5 billion), population growth was responsible for almost two-thirds of the increase in the most important greenhouse gas, carbon dioxide.
Methane, the second most significant greenhouse gas, is linked even more closely to population growth. The two biggest sources of methane emissions - livestock raising and rice farming - will increase as the demand for food swells.
SINCE the industrialized world consumes most of the earth's natural resources, it is primarily responsible for the global warming threat. In the future, however, 90 percent of population growth will occur in developing countries. Unlike the industrialized world, where 7 out of 10 women use effective contraception, less than half that many women in Africa and South Asia use birth control. Worldwide, 120 to 300 million couples who want comprehensive family planning services do not have access to them.
To stabilize population, industrialized nations must make family planning a reality for all people by committing the equivalent of one day's worldwide military spending to international population programs. The US agreed in the 1989 Amsterdam Declaration to the goal of making international family planning assistance universally available. This investment - $650 million in fiscal year 1993 - is both modest and cost-effective given that some in industry, government, and the scientific community are estimat ing that mitigation and adaptation to global warming could cost our society tens of billions of dollars.
In 1973, the US representative to the UN argued that "success in the population field" might "determine whether we can resolve successfully the other great questions of peace, prosperity, and individual rights that face the world." At the time George Bush wrote those words, about 4 billion people were on the planet. Unfortunately, President Bush, in an effort to placate extremists, has retreated from convictions that defined this forward-looking politician of the 1970s.
As it now stands, world leaders will conclude the Earth Summit having lost a historic opportunity to address world population. Efforts to cure environmental ills must include a global effort to slow and eventually stop population growth. Failing to do so will not only put "peace, prosperity, and individual rights" at risk, but could jeopardize our global environment.