Many of the world's greatest economic and security problems likely will emanate from sub-Saharan Africa unless the region can be more successfully integrated into the global economy, a top official of the World Bank warned Pittsburgh-area students yesterday.

While most of the world was growing richer after World War II, Africa was getting poorer, said Dr. Geoffrey Lamb, the World Bank's vice president for concessional finance and global partnerships. The bank makes low-interest loans to poor countries to help finance economic development projects.

"By 2015, most of Asia and Latin America are going to be OK," Lamb said. "Bangladesh is going to be OK." But much of Africa is likely to remain further mired in despair, he said, with potentially dire effects for the rest of the world.

Lamb spoke to several hundred Western Pennsylvania high school students assembled yesterday by the World Affairs Council of Pittsburgh at a forum at the Ramada Inn, Downtown. He also spoke at North Hills High School in Ross and La Roche College in McCandless.

"There are 700 million people in sub-Saharan Africa," Lamb said. "There will be a billion in 20 years. If you think you can leave a billion people out of a functioning world economy, you're mistaken."

The AIDS epidemic has ravaged many African nations, but malaria is an even greater threat. "Malaria is the biggest killer of children in Africa," Lamb said, "and it has gotten worse in the last 10 to 15 years."

Extreme poverty and political chaos also are providing a breeding grounds for the al-Qaida terror network and international drug rings, he said. Fifteen of the world's 18 poorest countries are in sub-Saharan Africa, and average per-capita annual income in those countries is just $350, he said.

The boundaries of African countries were drawn by European colonial powers in the 19th century, without regard to the settlement patterns of the native peoples. So strife has been almost constant, triggering a migration of refugees fleeing the violence. "In almost every African country, there are substantial groups of refugees from some other country," Lamb said.

Another huge problem that Africa faces in modernizing its economies is the vast size of the continent and the small number and poor quality of roads and railroads. Because of that, Lamb said, it costs Africa 70 percent more than the world average to get its goods to world markets.

Once Africans get their goods to market, they face political barriers. For example, West Africa is the world's most efficient producer of cotton, Lamb said, but West African cotton isn't competitive in the United States because of the subsidies that the U.S. government pays domestic cotton growers.

In response to questions from the audience, Lamb acknowledged another major problem for the continent's nations: a heavy burden of debt owed to developed countries and international financial institutions. "Africa has contracted far more debt than it can possibly repay," he said. And while many debts must be written off, Lamb said it is primarily up to African countries to get their financial house in order.

There are hopeful signs, Lamb said. Nigeria, Africa's most populous and potentially wealthiest country because of its oil reserves, seems to be getting serious about political corruption. In addition, a fragile truce has been arranged in a 30-year civil war in the Sudan between Muslims in the north and Christians and animists in the south.

But Africa's problems are so immense that they cannot be solved without help from the outside world, Lamb said. Aid is not the only answer, but it is critical, he argued. Lamb noted that pledges by individuals and countries to provide relief to Asian nations ravaged by last December's tsunami amounted to $1,000 for every man, woman and child in the affected countries, yet per-capita aid to sub-Saharan Africa's people is just $7 a year.