Short answers, pulled from the story.
The first domesticated sheep appeared in the Middle East before the first permanent settlements were constructed around 7000 BC. This event marked the beginning of a human practice that would shape civilizations for millennia. Before this moment, nomadic peoples relied on hunting wild game.
The Enclosure Movement was a dramatic shift when common lands used by peasants for crop farming were enclosed and converted to pastures controlled by gentries to favor the wool trade. This transformation stripped many rural families of their traditional rights to graze livestock on open fields. In some cases, entire villages were demolished to make way for large sheep pastures.
The Taylor Grazing Act of 1934 was enacted after the Great Depression to regulate the use of public land for grazing purposes. It responded to the environmental devastation caused by unchecked overgrazing during the preceding decades. The Act established the Grazing Service to issue permits and manage the number of animals allowed on federal lands.
Patch-burn grazing burns a third of a pasture each year to mimic the pre-historical relationship between bison and fire that once dominated the North American prairies. This technique involves burning one section of the land while leaving the others to rest, creating a dynamic mosaic of habitats. During the next two years, the next two patches are burned consecutively, then the cycle begins anew.
A 2013 Food and Agriculture Organization report estimated that livestock were responsible for 14.5% of anthropogenic greenhouse gas emissions. Studies comparing the methane emissions from grazing and feedlot cattle concluded that grass-fed cattle produce much more methane than grain-fed cattle. In New Zealand, methane and nitrous oxide from agriculture made up somewhat less than half of the country's greenhouse gas emissions in 2004.
In the United States, more than 100,000 sheep graze at solar arrays, primarily in the South. This practice is known as agrivoltaics and allows for shade for the animals and the vegetation so the soil retains a higher moisture level. Organizations such as the American Solar Grazing Association promote best practices for co-locating solar energy and grazing operations.