About one-third of the world's land surface is arid or semi-arid. The Earth's landmasses are losing 24 billion tons of topsoil and making 12 million hectares of the Earth useless for cultivation every year. The desertification is, however, not necessarily anthropogenic. So, first, we must elucidate what are the natural conditions of the desert. Then we can identify what are the artificial causes of desertification.