Desertification
Climatic change, including global warming (natural factor). The distribution of rainfall in the surrounding area of desert is uneven. From 1970 onwards, the world's weather has been changing. There has been less rain, and certain areas of the world are becoming drier. Drought affects the area surrounding a desert. As a result, many crops and animals have died. There is no vegetation to protect the soil. The topsoil is removed by sudden flash floods or strong wind. This makes the soil erode and the desert spread towards the surrounding area. Here are a few more ways of desertification: