Desertification is a serious problem that threatens the livelihoods and the lives of nearly a billion people in more than 100 countries. The total area affected covers one-third of the Earth's land surface. The people living in these areas are at risk of having to abandon their homes and migrate because the land can no longer sustain them. Though significant efforts have been initiated to combat desertification, the problem is worsening: each year, according to the Worldwatch Institute, the continents lose 24 billion tons of topsoil, creating a condition that often results in severe desertification.