This is an amazing and counter-intuitive take by Alan Savory on the cause and potential solution to the process of desertification that is proceeding over large areas of the world. The start is not promising because he seems to be finger-pointing at fossil fuels but that might be just to get the audience on side. By the time he gets to the end he suggests that the desertification will not be reversed by reducing emissions. The answer is to return grazing cattle in large herds that are kept together while they graze and fertilize the soil, then they are moved on to allow the soil to absorb the next fall of rain and produce green growth.
Almost 100 years ago I was an agricultural scientist and I might have been able to make a judgement on the science of it, he is convincing and I am inclined to give him the benefit of the doubt until more information comes in.
The presentation describes the various efforts that have been made around the world to save the grasslands by taking animals away or s hooting them in large numbers and locking up the national parks. He describes the laborious process of trial and error that eventually led back to something like the original state of the grasslands with nomadic herders moving their herds from one place to the next, grazing, dunging and pissing on a limited area and then moving on to a fresh area while the previous area turned green after the next rain.
In a nutshell the answer was not less stock on the range, but many more, properly managed, not running wild. And far from saving the ecology of the deserts by getting rid of farting animals, we save the world with more animals, and that saves people as well in those arid parts of the world where people live by way of animals rather than agriculture.
In a companion presentation he looks at the matter of management and stocking rates because the intuitive response to pasture degradation is to reduce the rate. His point is that the key variable is the amount of time the grass is exposed to the grazing animals, more than the stocking rate. So stock densely and move them on.