Final answer:
The people of the Inner Asian Steppe shifted from agriculture to livestock herding around 1500 BCE mainly due to climatic deterioration, which made the environment less suitable for farming and more amenable to pastoralism and a nomadic lifestyle.
Step-by-step explanation:
Scholars believe that the people of the Inner Asian Steppe began to abandon agriculture for livestock herding around 1500 BCE due to deterioration of the climate. This environmental change included periods of cooling and potential droughts, which led to a decrease in the land's capacity to support agriculture. As the grasslands shrank and agriculture became less sustainable, communities turned to nomadic pastoralism, moving herds through the landscape in search of pastures. This lifestyle was better suited to the steppe's climate and allowed for a mobile society that could find new grazing grounds and manage their livestock, including the defense against predators and raids on agricultural settlements when necessary. Nomadism required cultural adaptation, such as mastering horseback riding, which became an essential skill for managing herds and conducting raids or trade.