There is arguably no more pressing global problem than migration, brought even more sharply into focus by recent events. While it is hardly a new phenomenon, now as never before we find whole populations on the move, fleeing their homes to escape poverty, drought, famine, war, or to seek asylum from political oppression. Others are in search of greater economic opportunity, encouraged by the material wealth seen night after night on television. While in the past it might have taken weeks or longer for information to travel (as recently as World War II countries could claim ignorance of the death camps), instant communication makes us all aware of events around the world as they are unfolding. Indeed, images of "ethnic cleansing" in the Balkans finally caused Western governments to step in to stop the bloodshed. But awareness is not always enough; scenes of the genocide in central Africa did not produce a similar response, at least not in time to save millions from perishing. Brazilian-born photojournalist Sebastião Salgado has for many years been crisscrossing the Third World to bring to public view the changing face of humanity. Viewers may be familiar with his series Workers, documenting the many forms of manual labor disappearing as a result of industrialization. As people lose their livelihoods they are forced to move on. However, Salgado sees today's migrations as evidence of what he calls "a revolution in the way we live, produce, communicate, and travel," often summarized by the catchword "globalization." As Salgado wrote in his introduction to Migrations: "We are all affected by the widening gap between rich and poor, by the availability of information, by population growth in the Third World, by the mechanization of agriculture, by destruction of the environment, by nationalistic, ethnic, and religious bigotry." Salgado has spent six years traveling in forty countries to create this compelling document, which is divided into four sections. Migrants and Refugees: The Survival Instinct portrays Mexicans, Moroccans, Vietnamese, Bosnians, Kurds, and others as they head toward the crowded slums of the nearest metropolis. For others, the goal is the United States or Western Europe, even as these borders are made more difficult and dangerous to cross. In The African Tragedy: A Continent Adrift Salgado returned to the continent he had first visited in the 1970s, only to find its people more desperate. The only conclusion Salgado could draw from the largely unchecked 1994 genocide in Rwanda was that Africa had been dismissed as a lost cause by the West. Mozambique provided the only enclave of hope as the end of civil war there allowed refugees to return home. Latin America is the focus of Rural Exodus, Urban Disorder. Because the best land is held by a small minority of landowners, tens of millions of farmers are relocating to vastly overcrowded urban centers like Mexico City and São Paulo. There they continue their struggle for even a meager living; many are forced to beg. In Asia: The New World's Urban Face a similar movement toward urbanization has taken place, a change even more sudden than that in Latin America. In cities like Shanghai, shantytowns exist next to thriving financial centers. But despite their daily fight to survive, these new urban dwellers maintain hope for a better future. Many of Salgado's pictures are painful to view, but he asks that we do not hide our eyes. Because of his powerful images in newspapers, magazines, and here collected in an exhibition, we are well informed about the plight of refugees. But knowing is only the first step. Salgado will have failed if his photographs do not stimulate rethinking policies and attitudes and exercising our shared responsibility to act.