It is now more widely understood that, where rainfall is subject to a high degree of spatial variability, mobility is an ecological necessity. Mobile pastoralism provides a highly efficient way of managing the sparse vegetation and relatively low fertility of dryland soils. In essence, pastoralists accept the variability of productive inputs (pasture and rainfall) and adapt their social and herding systems accordingly. As a result, biological diversity is enhanced and ecosystem integrity and resilience is maintained.

Mobile pastoralists are a large and significant minority, and often an ethnic minority, in many countries around the world. Precise figures are hard to come by, but when all types of mobility are considered, nomadic and transhumant pastoralists may number between 100 and 200 million people globally. If extensive agro-pastoralists are included, the number rises very sharply, and such people are often a clear majority of dryland inhabitants.

Pastoralists constitute an estimated 16% of the population of the Sahelian Zone of Africa, but in a few countries such as Somalia and Mauritania, they are the majority of people. In parts of southern Europe, and even more in central Asia following de-collectivization, there is an ongoing resurgence of transhumant pastoralism.

Although mobile pastoralism is the most viable form of production and land use in most of the world’s fragile drylands, it is increasingly under threat from legal, economic, social and political disincentives and barriers to mobility of livestock. State of the art findings on the viability of pastoralism, and its positive influence on drylands ecosystems, are not communicated effectively to decision makers and alternative policy options still need to be formulated. Key policy gaps include regulation of transhumance, production investment, mobile (or otherwise appropriate) service delivery, conflict resolution, decentralisation and democracy adapted to mobile populations, alternative and complementary income generation opportunities and “exit strategies” for some pastoralists.

"Mobile pastoralism is clearly a viable and modern livelihood, and people are reverting to ways of living which a generation ago were thought to have disappeared."