Desertification led to desert sands overwhelming entire civilizations in the Biblical world and continues to threaten even Beijing by dumping millions of tons of sand on the city. It leads to millions of people suffering poverty, violence, social breakdown and war, or emigrating to other countries. Throughout history, and in universities, environmental organizations, and international agencies today livestock (cattle, sheep, goats, camels, horses) have been and continue to be blamed for causing desertification. Just too many animals.
In 1965 a Zimbabwean Ecologist Allan Savory, working on the problem of biodiversity loss/desertification in national parks with no livestock, discovered human belief had become scientific truth and was wrong.