9. Less than a quarter of our agricultural land is used to feed people directly. The rest is devoted to grazing and growing food for animals. Ecosystems of forest,wetland and grassland have been decimated to fuel the demand for land. Using so much land heightens topsoil loss,the use of harsh fertilizers and pesticides,and the need for irrigation water from dammed rivers. If people can shift away from meat,much of this land could be converted back to wilderness.