WASHINGTON - People do not normally leave their homes, their families, and their communities unless they have no other option. Yet as environmental stresses mount, we can expect to see a growing number of environmental refugees. Rising seas and increasingly devastating storms grab headlines, but expanding deserts, falling water tables, and toxic waste and radiation are also forcing people from their homes.
Advancing deserts are now on the move almost everywhere. The Sahara desert, for example, is expanding in every direction. As it advances northward, it is squeezing the populations of Morocco, Tunisia, and Algeria against the Mediterranean coast.
The Sahelian region of Africa - the vast swath of savannah that separates the southern Sahara desert from the tropical rainforests of central Africa - is shrinking as the desert moves southward. As the desert invades Nigeria, Africa's most populous country, from the north, farmers and herders are forced southward, squeezed into a shrinking area of productive land.
A 2006 U.N. conference on desertification in Tunisia projected that by 2020 up to 60 million people could migrate from sub-Saharan Africa to North Africa and Europe.
In Iran, villages abandoned because of spreading deserts or a lack of water number in the thousands. In Brazil, some 250,000 square miles of land are affected by desertification, much of it concentrated in the country's northeast.