Lester R. Brown: The Rising Tide of Environmental Refugees

Our early twenty-first century civilization is being squeezed between advancing deserts and rising seas. Measured by the biologically productive land area that can support human habitation, the earth is shrinking. Mounting population densities, once generated solely by population growth, are now also fueled by the relentless advance of deserts and may soon be affected by the projected rise in sea level. As overpumping depletes aquifers, millions more are forced to relocate in search of water.

Desert expansion in sub-Saharan Africa, principally in the Sahelian countries, is displacing millions of people