The world’s population is predicted to reach 10.1 billion by 2100, according to a United Nations report released May 3, 2011. Much of the growth is expected to occur in Africa, where the population could triple to 3.6 billion by the end of the century.

The figures for Africa are the most “disconcerting aspect” of the UN report, according to David Bloom, Clarence James Gamble Professor of Economics and Demography and chair, Department of Global Health and Population at HSPH. He joined four other experts for an online discussion of the report on The New York Times website.

“It took humankind more than 50,000 years to reach 1 billion, and now Africa alone will be adding more than that number in just four decades,” Bloom writes.

Bloom says that the projected population growth poses immense challenges for Africa. “The first and most urgent is the challenge of absorbing large numbers into productive employment. Failure to do this will sink Africa more deeply into a poverty trap and could be a major source of social and political instability,” he writes. The second challenge, says Bloom, is to reduce fertility by making contraception more available to delay childbearing or to limit the number of children. “It also involves moderating the high rates of desired fertility seen in much of Africa, which will naturally occur as the status and education of women improve and couples increasingly recognize that they will be better off with smaller families,” he writes.

Read The New York Times’ debate: “Can the Planet Support 10 Billion People?”