Poor farming practices have degraded the world's soils causing them to release carbon that should have stayed in the soil. In the past 150 years soils have released twice as much carbon as fuel burning. Improved farming methods could quickly rebuild degraded land and store enough carbon to offset the damage already done by fuel burning. Dr Rattan Lal of Ohio State University, a leading expert on soil carbon, estimates that the potential of economical carbon sequestration in world soils may be .65 billion to 1.1 billion tons per year for the next 50 years. This is enough to draw down atmospheric CO2 by 50 ppm by 2100. This is a one-time opportunity, however. We must ultimately stop burning fossil fuels.