Will the U.S. be a desert in 50 years?
What happens when climate variations and human actions such as land clearing, urbanization and unsustainable agricultural habits mix? The combination results in an ecological crisis: land degradation. When land degrades, it can no longer properly absorb, store and recycle water, nutrients and energy. Land degradation in arid, semi-arid and dry, subhumid areas (drylands) is called desertification. Water Image Gallery Seventy percent of drylands worldwide are degraded, and one-third of the world’s land surfaces are threatened — lands become more prone to flooding, wind damage and erosion, the quality of soil becomes poor, and productivity plummets [sources: