A recent review of statistics published by the United Nations Food and Agriculture Organization showed that global livestock numbers have increased steadily over the past 30 years. By 2030, livestock numbers in the developing world are expected to reach record highs that will surpass livestock population levels of the entire planet recorded at the turn of the 20th century while native grassland areas worldwide are expected to shrink by more than 12 million hectares over the same time period. This predicted trend is likely to trigger a substantial increase in forage demand, placing unprecedented pressures on rangelands of developing nations. The review of FAO data also revealed that counter to global trends, livestock inventories of developed countries have tended to decrease over the same period. This phenomenon has been particularly evident on rangelands of the western US where management emphasis has shifted from heavy investments in land improvements (common until the 1970s) to systems characterized by low capital investment focused on optimizing efficiency of per-capita livestock production. Knowledge-intensive management approaches involving selection of livestock biotypes better adapted to arid environments, and development of geospatial technology that allow more precise manipulation of the ruminant/plant interface have emerged as a result of this trend. Nonetheless, expected increases in the price of oil and costs of agricultural crop production used as animal feed could dramatically change this scenario, augmenting the role of rangelands as a source of forage for US livestock in the near future. Thus, development of strategies to increase sustainable herbivory of a broader array of native arid land forages (including woody plants) will most probably become a top priority shared by pastoral livestock systems of the developed and developing world alike.