World Leaders Gather at Rio for Earth Summit

ON this day, the United Nations claims, some 100 to 300 plant and animal species around the world will die out - far above what scientists believe is the natural rate of extinction, and largely attributable to human impact on the environment. Also today, the UN predicts, 40,000 people (mostly children) will die from hunger and hunger-related diseases. Much of that loss, too, is because of human impact on the environment.

These are the defining figures that have brought more than 100 heads of state or government, 10,000 delegates, and another 20,000 observers to the "Earth Summit," which starts here tomorrow.

Since the last gathering convened 20 years ago, both the seriousness of global environmental problems and general awareness about them have increased dramatically, as has the level of human suffering due to related poverty. (See summary of issues, Page 10.)

Maurice Strong, secretary-general of the UN Conference on Environment and Development, as the meeting here in Rio is officially called, puts the problem this way:

"Humanity is confronted with deepening disparities within and between nations. There is pervasive hunger, poverty, illiteracy, and ill health. The ecological consequences of ozone depletion, climate change, soil degradation, deforestation, loss of biodiversity and the increasing pollution of air, water and land threaten our common and sustainable future."

Mostafa Tolba, executive director of the United Nations Environment Program (UNEP), stresses that there are in fact no "global" ecological issues, but instead "the global crisis facing our planet is the sum total of the billions of daily actions of individuals, industries, and governments."

Among the problems detailed in the UN report:

r More than 25 billion tons of topsoil are lost each year due to erosion tied to agricultural activities. Use of chemical fertilizers has doubled during the past 20 years, but the period also saw the number of chronically hungry people increase by 90 million to a total of 550 million.

r Some 900 million people in urban areas are exposed to unhealthy levels of sulphur dioxide, and more than one billion are exposed to excessive levels of particulate emissions.

r Six and one-half million tons of garbage are dumped into the oceans every year.

There are other problems as well. James Gustave Speth, president of the World Resources Institute points out that because of a 50 percent increase in the rate of tropical deforestation during the 1980s, "an area ... about the size of the state of Washington now is lost each year; that's an acre and a half a second."

"Humans continue to alter in a few decades precise ecological balances that have evolved over billions of years," says Dr. Tolba of UNEP. "The facts show again and again - in dwindling fish stocks, projected shortfalls in fuel wood, quickening soil erosion, and millions of tons of greenhouse gases spewed into the atmosphere - that time is running out."

Brazil last year ended its tax subsidies that encouraged deforestation, but still cuts about 1.4 million hectares (3.46 million acres) annually. People problems here also make it a good spot to be discussing the development side of the Earth Summit equation: Rio has 11 million people, many of them packed into the notorious slums known as "favelas." According to the UN, 58 percent of all Brazilians are poor or indigent.

Many experts point out the close relationship between population growth and the twin environmental problems of pollution and resource depletion. There are 5.4 billion people in the world today, a figure that is expected to increase to more than 7 billion over the next two decades - 90 percent of that growth in developing countries where 1.1 billion people already live in poverty.

A recent study by the World Health Organization points out that current population growth rates mean "each year an additional 80 to 100 million will have to be fed, clothed, and sheltered." Over the next 20 years, that will add up to the need for a 36 percent increase in food, other agricultural products, and potable water - straining resources even further.

"The most immediate problems in the world are ill health and premature death caused by biological agents in the human environment; in water, food, air, and soil," the report states.

"The real enemies are poverty and social inequality," Edouard Saouma, director-general of the UN Food and Agriculture Organization warned last week. "How can hungry people be expected to protect natural resources and the environment, and concern themselves with the well-being of future generations, when their immediate survival is at stake?" The question is directed not only at chronically hungry people, but at those in more developed countries - which are both wealthier and use up resources and energy a t a much higher per-capita level.

The UN and the World Bank figure it will cost hundreds of billions of dollars over the next decade to begin turning around the poverty, population growth, pollution, and over-use of resources that have brought so many policy makers and advocacy groups to Rio this week. This will involve technology transfer, foreign aid, and debt relief. A proposed UN declaration to be considered over the next two weeks also states that "changes in life styles of the rich to those that are less polluting and wasteful is e ssential to reaching sustainable development."

But in the end, UNCED organizer Maurice Strong told a group of scientists and religious leaders who met recently at the United States Senate, "The real key to survival of the human species is a revival of the moral and spiritual values which are the undergirding of our civilization."