Threats of AIDS, water depletion, and shrinking cropland could send death rates soaring early in the next century, according to a trio of World watch Institute researchers who have just published Beyond Malthus: Nineteen Dimensions of the Population Challenge.

Death rates are booming or likely to escalate, especially in sub-Saharan Africa and the Indian subcontinent, which account for one-third of the world's population. The biggest danger is posed by HIV, the AIDS virus, researchers say.

"It is an international emergency of epidemic proportions, one that could claim more lives in the early part of the next century than World War II," says World watch founder Lester R. Brown, one of the authors. Already, one-fifth to one-fourth of the adult populations in Zimbabwe, Namibia, Zambia, Swaziland, and Botswana are infected. In Botswana, life expectancy has dropped to 44 from 62 in 1990.

Barring a medical miracle, many African nations will lose one-fifth of their adult populations to AIDS within the next decade, Worldwatch contends, spurring a death rate unknown since the bubonic plague in fourteenth-century Europe.

The trend marks the first time that rising death rates are slowing world population growth since China's famine four decades ago caused 30 million deaths.

Clive Calver, president of World Relief, notes that two-thirds of the 33 million people infected with HIV live in Africa. He believes the only way to stem the AIDS death rate in Africa will be for the church to teach sexual morality. "We've got to empower African churches to run programs of care and prevention."