Although land is damaged in numerous ways, our particular interest is degradation by soil erosion. Any land is potentially threatened where accelerated erosion occurs. Land must be protected against excessive soil erosion to remain a viable resource indefinitely. A few years of careless use can greatly accelerate soil erosion that degrades the land permanently, especially for food production (figure 8.1). Some lands degraded by erosion can be restored, but at a prohibitive cost, including removing the land temporarily from food production. Countries with severe population pressure may not have the luxury of permanently, or even temporarily, retiring land from food production or may not have the resources to apply soil conservation to the land if the land stays in production.